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Li H, Daniel AJ, Buchanan CE, Nery F, Morris DM, Li S, Huang Y, Sousa JA, Sourbron S, Mendichovszky IA, Thomas DL, Priest AN, Francis ST. Improvements in Between-Vendor MRI Harmonization of Renal T 2 Mapping using Stimulated Echo Compensation. J Magn Reson Imaging 2024. [PMID: 38380700 DOI: 10.1002/jmri.29282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND T2 mapping is valuable to evaluate pathophysiology in kidney disease. However, variations in T2 relaxation time measurements across MR scanners and vendors may occur requiring additional correction. PURPOSE To harmonize renal T2 measurements between MR vendor platforms, and use an extended-phase-graph-based fitting method ("StimFit") to correct stimulated echoes and reduce between-vendor variations. STUDY TYPE Prospective. SUBJECTS 8 healthy "travelling" volunteers (37.5% female, 32 ± 6 years) imaged on four MRI systems across three vendors at four sites, 10 healthy volunteers (50% female, 32 ± 8 years) scanned multiple times on a given MR scanner for repeatability evaluation. ISMRM/NIST system phantom scanned for evaluation of T2 accuracy. FIELD STRENGTH/SEQUENCE 3T, multiecho spin-echo sequence. ASSESSMENT T2 images fit using conventional monoexponential fitting and "StimFit." Mean absolute percentage error (MAPE) of phantom measurements with reference T2 values. Average cortex and medulla T2 values compared between MR vendors, with masks obtained from T2 -weighted images and T1 maps. Full-width-at-half-maximum (FWHM) T2 distributions to evaluate local homogeneity of measurements. STATISTICAL TESTS Coefficient of variation (CV), linear mixed-effects model, analysis of variance, student's t-tests, Bland-Altman plots, P-value <0.05 considered statistically significant. RESULTS In the ISMRM/NIST phantom, "StimFit" reduced the MAPE from 4.9%, 9.1%, 24.4%, and 18.1% for the four sites (three vendors) to 3.3%, 3.0%, 6.6%, and 4.1%, respectively. In vivo, there was a significant difference in kidney T2 measurements between vendors using a monoexponential fit, but not with "StimFit" (P = 0.86 and 0.92, cortex and medulla, respectively). The intervendor CVs of T2 measures were reduced from 8.0% to 2.6% (cortex) and 7.1% to 2.8% (medulla) with StimFit, resulting in no significant differences for the CVs of intravendor repeat acquisitions (P = 0.13 and 0.05). "StimFit" significantly reduced the FWHM of T2 distributions in the cortex and whole kidney. DATA CONCLUSION Stimulated-echo correction reduces renal T2 variation across MR vendor platforms. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Hao Li
- The Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, China
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Alexander J Daniel
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
| | | | - Fábio Nery
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - David M Morris
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Shaohang Li
- The Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, China
| | - Yuan Huang
- Department of Radiology, University of Cambridge, Cambridge, UK
- EPSRC Cambridge Mathematics of Information in Healthcare Hub, University of Cambridge, Cambridge, UK
| | - João A Sousa
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Steven Sourbron
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Iosif A Mendichovszky
- Department of Radiology, University of Cambridge, Cambridge, UK
- Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - David L Thomas
- Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Andrew N Priest
- Department of Radiology, University of Cambridge, Cambridge, UK
- Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and School of Medicine, Nottingham, UK
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Selby NM, Francis ST. Assessment of Acute Kidney Injury using MRI. J Magn Reson Imaging 2024. [PMID: 38334370 DOI: 10.1002/jmri.29281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/10/2024] Open
Abstract
There has been growing interest in using quantitative magnetic resonance imaging (MRI) to describe and understand the pathophysiology of acute kidney injury (AKI). The ability to assess kidney blood flow, perfusion, oxygenation, and changes in tissue microstructure at repeated timepoints is hugely appealing, as this offers new possibilities to describe nature and severity of AKI, track the time-course to recovery or progression to chronic kidney disease (CKD), and may ultimately provide a method to noninvasively assess response to new therapies. This could have significant clinical implications considering that AKI is common (affecting more than 13 million people globally every year), harmful (associated with short and long-term morbidity and mortality), and currently lacks specific treatments. However, this is also a challenging area to study. After the kidney has been affected by an initial insult that leads to AKI, complex coexisting processes ensue, which may recover or can progress to CKD. There are various preclinical models of AKI (from which most of our current understanding derives), and these differ from each other but more importantly from clinical AKI. These aspects are fundamental to interpreting the results of the different AKI studies in which renal MRI has been used, which encompass different settings of AKI and a variety of MRI measures acquired at different timepoints. This review aims to provide a comprehensive description and interpretation of current studies (both preclinical and clinical) in which MRI has been used to assess AKI, and discuss future directions in the field. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 3.
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Affiliation(s)
- Nicholas M Selby
- Centre for Kidney Research and Innovation, Academic Unit for Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, UK
- Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and The University of Nottingham, Nottingham, UK
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Gullapudi VRL, Cox EF, Buchanan CE, Canaud B, White K, Taal MW, Selby NM, Francis ST. Randomized trial comparing standard versus thermocontrolled haemodialysis using intradialytic cardiac, brain and renal magnetic resonance imaging. Nephrol Dial Transplant 2024; 39:233-241. [PMID: 37433572 PMCID: PMC10828207 DOI: 10.1093/ndt/gfad150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Indexed: 07/13/2023] Open
Abstract
BACKGROUND Ischaemic end-organ damage during haemodialysis (HD) is a significant problem that may be ameliorated by intradialytic cooling. A randomised trial was performed to compare standard HD (SHD; dialysate temperature 37°C) and programmed cooling of the dialysate [thermocontrolled HD (TCHD)] using multiparametric magnetic resonance imaging (MRI) to assess structural, functional and blood flow changes in the heart, brain and kidneys. METHODS Prevalent HD patients were randomly allocated to receive either SHD or TCHD for 2 weeks before undergoing serial MRI at four time points: pre-, during (30 min and 180 min) and post-dialysis. MRI measures include cardiac index, myocardial strain, longitudinal relaxation time (T1), myocardial perfusion, internal carotid and basilar artery flow, grey matter perfusion and total kidney volume. Participants then crossed to the other modality to repeat the study protocol. RESULTS Eleven participants completed the study. Separation in blood temperature between TCHD (-0.1 ± 0.3°C) and SHD (+0.3 ± 0.2°C; P = .022) was observed, although there was no difference in tympanic temperature changes between arms. There were significant intradialytic reductions in cardiac index, cardiac contractility (left ventricular strain), left carotid and basilar artery blood flow velocities, total kidney volume, longitudinal relaxation time (T1) of the renal cortex and transverse relaxation rate (T2*) of the renal cortex and medulla, but no differences between arms. Pre-dialysis T1 of the myocardium and left ventricular wall mass index were lower after 2 weeks of TCHD compared with SHD [1266 ms (interquartile range 1250-1291) versus 1311 ± 58 ms, P = .02; 66 ± 22 g/m2 versus 72 ± 23 g/m2, P = .004]. CONCLUSIONS HD adversely affects cardiac function, reduces carotid and basilar artery blood flow and total kidney volume, but mild dialysate cooling using a biofeedback module did not result in differences in intradialytic MRI measures compared with SHD.
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Affiliation(s)
- Venkata R Latha Gullapudi
- Centre for Kidney Research and Innovation, University of Nottingham, Derby, UK
- Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Bernard Canaud
- Global Medical Office, Fresenius Medical Care, Bad Homburg, Germany
| | - Kelly White
- Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, University of Nottingham, Derby, UK
- Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Derby, UK
- Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
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Thapaliya G, Eldeghaidy S, Radford SJ, Francis ST, Moran GW. An examination of resting-state functional connectivity in patients with active Crohn's disease. Front Neurosci 2023; 17:1265815. [PMID: 38125406 PMCID: PMC10731262 DOI: 10.3389/fnins.2023.1265815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Background Alterations in resting state functional connectivity (rs-FC) in Crohn's Disease (CD) have been documented in default mode network (DMN) and frontal parietal network (FPN) areas, visual, cerebellar, salience and attention resting-state-networks (RSNs), constituting a CD specific neural phenotype. To date, most studies are in patients in remission, with limited studies in active disease. Methods Twenty five active CD cases and 25 age-, BMI- and gender-matched healthy controls (HC) were recruited to a resting-state-functional Magnetic Resonance Imaging (rs-fMRI) study. Active disease was defined as C-reactive protein>5 mg/dL, faecal calprotectin>250 μg/g, or through ileocolonoscopy or MRE. rs-fMRI data were analysed using independent component analysis (ICA) and dual regression. Differences in RSNs between HCs and active CD were assessed, and rs-FC was associated with disease duration and abdominal pain. Results Increased connectivity in the FPN (fusiform gyrus, thalamus, caudate, posterior cingulate cortex, postcentral gyrus) and visual RSN (orbital frontal cortex) were observed in CD versus HC. Decreased activity was observed in the salience network (cerebellum, postcentral gyrus), DMN (parahippocampal gyrus, cerebellum), and cerebellar network (occipital fusiform gyrus, cerebellum) in CD versus HCs. Greater abdominal pain scores were associated with lower connectivity in the precuneus (visual network) and parietal operculum (salience network), and higher connectivity in the cerebellum (frontal network). Greater disease duration was associated with greater connectivity in the middle temporal gyrus and planum temporale (visual network). Conclusion Alterations in rs-FC in active CD in RSNs implicated in cognition, attention, emotion, and pain may represent neural correlates of chronic systemic inflammation, abdominal pain, disease duration, and severity.
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Affiliation(s)
- Gita Thapaliya
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Sally Eldeghaidy
- Division of Food, Nutrition and Dietetics, School of Biosciences, The University of Nottingham, Loughborough, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and School of Medicine, The University of Nottingham, Nottingham, United Kingdom
| | - Shellie J. Radford
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and School of Medicine, The University of Nottingham, Nottingham, United Kingdom
| | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and School of Medicine, The University of Nottingham, Nottingham, United Kingdom
| | - Gordon William Moran
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and School of Medicine, The University of Nottingham, Nottingham, United Kingdom
- Translational Medical Sciences Unit, University of Nottingham, Nottingham, United Kingdom
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5
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Francis ST, Selby NM, Taal MW. Magnetic Resonance Imaging to Evaluate Kidney Structure, Function, and Pathology: Moving Toward Clinical Application. Am J Kidney Dis 2023; 82:491-504. [PMID: 37187282 DOI: 10.1053/j.ajkd.2023.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/20/2023] [Indexed: 05/17/2023]
Abstract
Recent advances in multiparametric magnetic resonance imaging (MRI) allow multiple quantitative measures to assess kidney morphology, tissue microstructure, oxygenation, kidney blood flow, and perfusion to be collected in a single scan session. Animal and clinical studies have investigated the relationship between the different MRI measures and biological processes, although their interpretation can be complex due to variations in study design and generally small participant numbers. However, emerging themes include the apparent diffusion coefficient derived from diffusion-weighted imaging, T1 and T2 mapping parameters, and cortical perfusion being consistently associated with kidney damage and predicting kidney function decline. Blood oxygen level-dependent (BOLD) MRI has shown inconsistent associations with kidney damage markers but has been predictive of kidney function decline in several studies. Therefore, multiparametric MRI of the kidneys has the potential to address the limitations of existing diagnostic methods to provide a noninvasive, noncontrast, and radiation-free method to assess whole kidney structure and function. Barriers to be overcome to facilitate widespread clinical application include improved understanding of biological factors that impact MRI measures, development of a larger evidence base for clinical utility, standardization of MRI protocols, automation of data analysis, determining optimal combination of MRI measures, and health economic evaluation.
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Affiliation(s)
- Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham; NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, Academic Unit for Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham; Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, United Kingdom
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, Academic Unit for Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham; Department of Renal Medicine, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, United Kingdom.
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Hubbard Cristinacce PL, Markus JE, Punwani S, Mills R, Lopez MY, Grech-Sollars M, Fasano F, Waterton JC, Thrippleton MJ, Hall MG, O'Connor JPB, Francis ST, Statton B, Murphy K, So PW, Hyare H. Steps on the Path to Clinical Translation: A workshop by the British and Irish Chapter of the ISMRM. Magn Reson Med 2023. [PMID: 37222226 DOI: 10.1002/mrm.29704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/24/2023] [Accepted: 04/24/2023] [Indexed: 05/25/2023]
Abstract
The British and Irish Chapter of the International Society for Magnetic Resonance in Medicine (BIC-ISMRM) held a workshop entitled "Steps on the path to clinical translation" in Cardiff, UK, on 7th September 2022. The aim of the workshop was to promote discussion within the MR community about the problems and potential solutions for translating quantitative MR (qMR) imaging and spectroscopic biomarkers into clinical application and drug studies. Invited speakers presented the perspectives of radiologists, radiographers, clinical physicists, vendors, imaging Contract/Clinical Research Organizations (CROs), open science networks, metrologists, imaging networks, and those developing consensus methods. A round-table discussion was held in which workshop participants discussed a range of questions pertinent to clinical translation of qMR imaging and spectroscopic biomarkers. Each group summarized their findings via three main conclusions and three further questions. These questions were used as the basis of an online survey of the broader UK MR community.
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Affiliation(s)
- Penny L Hubbard Cristinacce
- Quantitative Biomedical Imaging Laboratory, Division of Cancer Sciences, School of Health Sciences, Faculty of Biology Medicine & Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Julia E Markus
- Centre for Medical Imaging, Division of Medicine, University College London, London, UK
| | - Shonit Punwani
- Centre for Medical Imaging, Division of Medicine, University College London, London, UK
| | - Rebecca Mills
- University of Oxford, Centre for Clinical Magnetic Resonance Research, The John Radcliffe Hospital, Oxford, UK
| | - Maria Yanez Lopez
- MR Physics Group, Department of Medical Physics and Clinical Engineering, Swansea Bay University Health Board, Singleton Hospital, Swansea, UK
| | - Matthew Grech-Sollars
- Department of Computer Science, University College London, London, UK
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
| | | | - John C Waterton
- Centre for Imaging Sciences, Division of Informatics Imaging & Data Sciences, School of Health Sciences, Faculty of Biology Medicine & Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester, UK
| | - Michael J Thrippleton
- Edinburgh Imaging/Centre for Clinical Brain Sciences, University of Edinburgh, The Chancellor's Building, Edinburgh, UK
| | - Matt G Hall
- National Physical Laboratory, Teddington, UK
| | - James P B O'Connor
- Quantitative Biomedical Imaging Laboratory, Division of Cancer Sciences, School of Health Sciences, Faculty of Biology Medicine & Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Ben Statton
- MRC London Institute of Medical Sciences, Du Cane Road, Imperial College London, London, UK
| | - Kevin Murphy
- Cardiff University Brain Research Imaging Centre, School of Physics and Astronomy, Cardiff, UK
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Harpreet Hyare
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
- Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, UK
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Iglesias M, McGrath DM, Tretyakov MV, Francis ST. Ensemble Kalman inversion for magnetic resonance elastography. Phys Med Biol 2022; 67. [PMID: 36322986 DOI: 10.1088/1361-6560/ac9fa1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 11/01/2022] [Indexed: 11/29/2022]
Abstract
Magnetic resonance elastography (MRE) is an MRI-based diagnostic method for measuring mechanical properties of biological tissues. MRE measurements are processed by an inversion algorithm to produce a map of the biomechanical properties. In this paper a new and powerful method (ensemble Kalman inversion with level sets (EKI)) of MRE inversion is proposed and tested. The method has critical advantages: material property variation at disease boundaries can be accurately identified, and uncertainty of the reconstructed material properties can be evaluated by consequence of the probabilistic nature of the method. EKI is tested in 2D and 3D experiments with synthetic MRE data of the human kidney. It is demonstrated that the proposed inversion method is accurate and fast.
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Affiliation(s)
- Marco Iglesias
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Deirdre M McGrath
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - M V Tretyakov
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Susan T Francis
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
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Bradley CR, Cox EF, Palaniyappan N, Aithal GP, Francis ST, Guha IN. Variability of noninvasive MRI and biological markers in compensated cirrhosis: insights for assessing disease progression. Eur Radiol Exp 2022; 6:52. [PMID: 36274113 PMCID: PMC9588852 DOI: 10.1186/s41747-022-00303-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 08/04/2022] [Indexed: 11/11/2022] Open
Abstract
Background We annually monitored stable compensated cirrhosis (CC) patients to evaluate serial variation in blood serum, liver stiffness, and multiparametric magnetic resonance imaging (mpMRI) measures to provide reference change values (RCV) and sample size measures for future studies. Methods Patients were recruited from a prospectively followed CC cohort, with assessments at baseline and annually over three years. We report on blood markers, transient elastography liver stiffness measures (LSM) and noninvasive mpMRI (volume, T1 mapping, blood flow, perfusion) of the liver, spleen, kidneys, and heart in a stable CC group and a healthy volunteer (HV) group. Coefficient of variation over time (CoVT) and RCV are reported, along with hazard ratio to assess disease progression. Sample size estimates to power future trials of cirrhosis regression on mpMRI are presented. Results Of 60 CC patients enrolled, 28 with stable CC were followed longitudinally and compared to 10 HVs. CoVT in mpMRI measures was comparable between CC and HV groups. CoVT of Enhanced Liver Fibrosis score was low (< 5%) compared to Fibrosis-4 index (17.9%) and Aspartate Aminotransferase-to-Platelet-Ratio Index (19.4%). A large CoVT (20.7%) and RCV (48.3%) were observed for LSM. CoVT and RCV were low for liver, spleen, and renal T1 values (CoVT < 5%, RCV < 8%) and volume (CoVT < 10%, RCV < 16%); haemodynamic measures were high (CoVT 12–25%, RCV 16–47%). Conclusions Evidence of low CoVT and RCV in multiorgan T1 values. RCV and sample size estimates are provided for future longitudinal multiorgan monitoring in CC patients. Trial registration ClinicalTrials.gov identifier: NCT02037867, Registered: 05/01/2013.
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Khalife S, Francis ST, Schluppeck D, Sánchez-Panchuelo RM, Besle J. Fast Event-Related Mapping of Population Fingertip Tuning Properties in Human Sensorimotor Cortex at 7T. eNeuro 2022; 9:ENEURO.0069-22.2022. [PMID: 36194620 PMCID: PMC9480917 DOI: 10.1523/eneuro.0069-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/11/2022] [Accepted: 07/31/2022] [Indexed: 12/15/2022] Open
Abstract
fMRI studies that investigate somatotopic tactile representations in the human cortex typically use either block or phase-encoded stimulation designs. Event-related (ER) designs allow for more flexible and unpredictable stimulation sequences than the other methods, but they are less efficient. Here, we compared an efficiency-optimized fast ER design (2.8-s average intertrial interval; ITI) to a conventional slow ER design (8-s average ITI) for mapping voxelwise fingertip tactile tuning properties in the sensorimotor cortex of six participants at 7 Tesla. The fast ER design yielded more reliable responses compared with the slow ER design, but with otherwise similar tuning properties. Concatenating the fast and slow ER data, we demonstrate in each individual brain the existence of two separate somatotopically-organized tactile representations of the fingertips, one in the primary somatosensory cortex (S1) on the postcentral gyrus, and the other shared across the motor and premotor cortices on the precentral gyrus. In both S1 and motor representations, fingertip selectivity decreased progressively, from narrowly-tuned Brodmann area (BA) 3b and BA4a, respectively, toward associative parietal and frontal regions that responded equally to all fingertips, suggesting increasing information integration along these two pathways. In addition, fingertip selectivity in S1 decreased from the cortical representation of the thumb to that of the pinky.
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Affiliation(s)
- Sarah Khalife
- Department of Psychology, American University of Beirut, Beirut, 11072020, Lebanon
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, NG72RD, United Kingdom
- National Institute for Health and Care Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Denis Schluppeck
- Visual Neuroscience Group, School of Psychology, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Rosa-Maria Sánchez-Panchuelo
- National Institute for Health and Care Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Julien Besle
- Department of Psychology, American University of Beirut, Beirut, 11072020, Lebanon
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de Boer A, Villa G, Bane O, Bock M, Cox EF, Dekkers IA, Eckerbom P, Fernández‐Seara MA, Francis ST, Haddock B, Hall ME, Hall Barrientos P, Hermann I, Hockings PD, Lamb HJ, Laustsen C, Lim RP, Morris DM, Ringgaard S, Serai SD, Sharma K, Sourbron S, Takehara Y, Wentland AL, Wolf M, Zöllner FG, Nery F, Caroli A. Consensus-Based Technical Recommendations for Clinical Translation of Renal Phase Contrast MRI. J Magn Reson Imaging 2022; 55:323-335. [PMID: 33140551 PMCID: PMC9291014 DOI: 10.1002/jmri.27419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool. PURPOSE To build technical recommendations for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies. STUDY TYPE Systematic consensus process using a modified Delphi method. POPULATION Not applicable. SEQUENCE FIELD/STRENGTH Renal fast gradient echo-based 2D PC-MRI. ASSESSMENT An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4-10) years of experience in 2D PC-MRI formulated consensus statements on renal 2D PC-MRI in two rounds of surveys. Starting from a recently published systematic review article, literature-based and data-driven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated. STATISTICAL TESTS Consensus was defined as ≥75% unanimity in response, and a clear preference was defined as 60-74% agreement among the experts. RESULTS Among 60 statements, 57 (95%) achieved consensus after the second-round survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PC-MRI data acquisition, processing, and reporting. DATA CONCLUSION These recommendations might promote a widespread adoption of renal PC-MRI, and may help foster the set-up of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PC-MRI. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Anneloes de Boer
- Department of RadiologyUniversity Medical Center Utrecht, Utrecht UniversityUtrechtThe Netherlands
| | - Giulia Villa
- Department of BioengineeringIstituto di Ricerche Farmacologiche Mario Negri IRCCSBergamoItaly
| | - Octavia Bane
- Biomedical Engineering and Imaging Institute/RadiologyIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
| | - Michael Bock
- Department of Radiology ‐ Medical Physics, Medical CenterUniversity of Freiburg, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Eleanor F. Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and AstronomyUniversity of NottinghamNottinghamUK
| | - Ilona A. Dekkers
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Per Eckerbom
- Department of Surgical SciencesUppsala UniversityUppsalaSweden
| | | | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and AstronomyUniversity of NottinghamNottinghamUK
| | - Bryan Haddock
- Department of Clinical Physiology, Nuclear Medicine and PET, RigshospitaletCopenhagen University HospitalCopenhagenDenmark
| | - Michael E. Hall
- Department of MedicineUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | | | - Ingo Hermann
- Computer Assisted Clinical Medicine, Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty MannheimHeidelberg UniversityMannheimGermany
| | | | - Hildo J. Lamb
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Christoffer Laustsen
- Department of Clinical Medicine, MR Research CentreAarhus UniversityAarhusDenmark
| | - Ruth P. Lim
- Departments of Radiology, Surgery and MedicineThe University of MelbourneParkvilleVictoriaAustralia
- Department of RadiologyAustin HealthHeidelbergVictoriaAustralia
| | - David M. Morris
- Centre for Inflammation ResearchUniversity of Edinburgh, Edinburgh BioquarterEdinburghUK
| | - Steffen Ringgaard
- Department of Clinical Medicine, MR Research CentreAarhus UniversityAarhusDenmark
| | - Suraj D. Serai
- Department of RadiologyChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Kanishka Sharma
- Department of Imaging, Infection, Immunity and Cardiovascular DiseaseThe University of SheffieldSheffieldUK
| | - Steven Sourbron
- Department of Imaging, Infection, Immunity and Cardiovascular DiseaseThe University of SheffieldSheffieldUK
| | - Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic ImagingNagoya University, Graduate School of MedicineNagoyaJapan
| | | | - Marcos Wolf
- High Field MR Center, Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Frank G. Zöllner
- Computer Assisted Clinical Medicine, Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty MannheimHeidelberg UniversityMannheimGermany
| | - Fabio Nery
- Developmental Imaging and Biophysics SectionUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Anna Caroli
- Department of BioengineeringIstituto di Ricerche Farmacologiche Mario Negri IRCCSBergamoItaly
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McGrath DM, Bradley CR, Francis ST. In silicoevaluation and optimisation of magnetic resonance elastography of the liver. Phys Med Biol 2021; 66. [PMID: 34678798 DOI: 10.1088/1361-6560/ac3263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/22/2021] [Indexed: 11/11/2022]
Abstract
Objective.Magnetic resonance elastography (MRE) is widely adopted as a biomarker of liver fibrosis. However,in vivoMRE accuracy is difficult to assess.Approach.Finite element model (FEM) simulation was employed to evaluate liver MRE accuracy and inform methodological optimisation. MRE data was simulated in a 3D FEM of the human torso including the liver, and compared with spin-echo echo-planar imaging MRE acquisitions. The simulated MRE results were compared with the ground truth magnitude of the complex shear modulus (∣G*∣) for varying: (1) ground truth liver ∣G*∣; (2) simulated imaging resolution; (3) added noise; (4) data smoothing. Motion and strain-based signal-to-noise (SNR) metrics were evaluated on the simulated data as a means to select higher-quality voxels for preparation of acquired MRE summary statistics of ∣G*∣.Main results.The simulated MRE accuracy for a given ground truth ∣G*∣ was found to be a function of imaging resolution, motion-SNR and smoothing. At typical imaging resolutions, it was found that due to under-sampling of the MRE wave-field, combined with motion-related noise, the reconstructed simulated ∣G*∣ could contain errors on the scale of the difference between liver fibrosis stages, e.g. 54% error for ground truth ∣G*∣ = 1 kPa. Optimum imaging resolutions were identified for given ground truth ∣G*∣ and motion-SNR levels.Significance.This study provides important knowledge on the accuracy and optimisation of liver MRE. For example, for motion-SNR ≤ 5, to distinguish between liver ∣G*∣ of 2 and 3 kPa (i.e. early-stage liver fibrosis) it was predicted that the optimum isotropic voxel size is 4-6 mm.
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Affiliation(s)
- Deirdre M McGrath
- Sir Peter Mansfield Imaging Centre, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.,NIHR Nottingham Biomedical Research Centre, Radiological Sciences, Division of Clinical Neuroscience, Queens Medical Centre, Nottingham, NG7 2UH, United Kingdom
| | - Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.,NIHR Nottingham Biomedical Research Centre, Radiological Sciences, Division of Clinical Neuroscience, Queens Medical Centre, Nottingham, NG7 2UH, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.,NIHR Nottingham Biomedical Research Centre, Radiological Sciences, Division of Clinical Neuroscience, Queens Medical Centre, Nottingham, NG7 2UH, United Kingdom
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12
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McGing JJ, Radford SJ, Francis ST, Serres S, Greenhaff PL, Moran GW. Review article: The aetiology of fatigue in inflammatory bowel disease and potential therapeutic management strategies. Aliment Pharmacol Ther 2021; 54:368-387. [PMID: 34228817 DOI: 10.1111/apt.16465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 09/30/2020] [Accepted: 05/20/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Fatigue is the inability to achieve or maintain an expected work output resulting from central or peripheral mechanisms. The prevalence of inflammatory bowel disease (IBD) fatigue can reach 86% in active disease, persisting in 50%-52% of patients with mild to inactive disease. Fatigue is the commonest reason for work absence in IBD, and patients often report fatigue burden to be greater than that of primary disease symptoms. Relatively few evidence-based treatment options exist, and the aetiology is poorly understood. AIM To review the available data and suggest a possible aetiology of IBD fatigue and to consider the efficacy of existing management strategies and highlight potential future interventions. METHODS We reviewed fatigue-related literature in IBD using PubMed database. RESULTS Disease related factors such as inflammation and pharmacological treatments negatively impact skeletal muscle and brain physiology, likely contributing to fatigue symptoms. Secondary factors such as malnutrition, anaemia, sleep disturbance and psychological comorbidity are potential determinants. Immune profile, faecal microbiota composition and physical fitness differ significantly between fatigued and non-fatigued patients, suggesting these may be aetiological factors. Solution-focused therapy, high-dosage thiamine supplementation and biological therapy may reduce fatigue perception in IBD. The effect of physical activity interventions is inconclusive. CONCLUSIONS A multimodal approach is likely required to treat IBD fatigue. Established reversible factors like anaemia, micronutrient deficiencies and active disease should initially be resolved. Psychosocial intervention shows potential efficacy in reducing fatigue perception in quiescent disease. Restoring physical deconditioning by exercise training intervention may further improve fatigue burden.
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Affiliation(s)
- Jordan J McGing
- School of Medicine, University of Nottingham, Nottingham, UK.,Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
| | - Shellie Jean Radford
- School of Medicine, University of Nottingham, Nottingham, UK.,National Institute of Health Research Nottingham Biomedical Research Centre (NIHR), Nottingham University Hospitals and University of Nottingham, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.,National Institute of Health Research Nottingham Biomedical Research Centre (NIHR), Nottingham University Hospitals and University of Nottingham, Nottingham, UK
| | - Sébastien Serres
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Paul L Greenhaff
- National Institute of Health Research Nottingham Biomedical Research Centre (NIHR), Nottingham University Hospitals and University of Nottingham, Nottingham, UK.,MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Gordon W Moran
- School of Medicine, University of Nottingham, Nottingham, UK.,National Institute of Health Research Nottingham Biomedical Research Centre (NIHR), Nottingham University Hospitals and University of Nottingham, Nottingham, UK
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13
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Burley CV, Francis ST, Whittaker AC, Mullinger KJ, Lucas SJE. Measuring resting cerebral haemodynamics using MRI arterial spin labelling and transcranial Doppler ultrasound: Comparison in younger and older adults. Brain Behav 2021; 11:e02126. [PMID: 34032379 PMCID: PMC8323033 DOI: 10.1002/brb3.2126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/23/2021] [Accepted: 03/06/2021] [Indexed: 02/04/2023] Open
Abstract
INTRODUCTION Resting cerebral blood flow (CBF) and perfusion measures have been used to determine brain health. Studies showing variation in resting CBF with age and fitness level using different imaging approaches have produced mixed findings. We assess the degree to which resting CBF measures through transcranial Doppler (TCD) and arterial spin labeling (ASL) MRI provide complementary information in older and younger, fit and unfit cohorts. METHODS Thirty-five healthy volunteers (20 younger: 24 ± 7y; 15 older: 66 ± 7y) completed two experimental sessions (TCD/MRI). Aging and fitness effects within and between imaging modalities were assessed. RESULTS Middle cerebral artery blood velocity (MCAv, TCD) was lower and transit time (MRI) slower in older compared with younger participants (p < .05). The younger group had higher gray matter cerebral perfusion (MRI) than the older group, albeit not significantly (p = .13). Surprisingly, fitness effects in the younger group (decrease/increase in MCAv/transit time with fitness, respectively) opposed the older group (increase/decrease in MCAv/transit time). Whole cohort transit times correlated with MCAv (r=-0.63; p < .05), whereas tissue perfusion did not correlate with TCD measures. CONCLUSION TCD and MRI modalities provide complementary resting CBF measures, with similar effects across the whole cohort and between subgroups (age/fitness) if metrics are comparable (e.g., velocity [TCD] versus transit time [MRI]).
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Affiliation(s)
- Claire V Burley
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK.,Dementia Centre for Research Collaboration, School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, UK
| | - Anna C Whittaker
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK.,Faculty of Health Sciences and Sport, University of Stirling, Stirling, UK
| | - Karen J Mullinger
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, UK.,School of Psychology, University of Birmingham, UK
| | - Samuel J E Lucas
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK
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14
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Dewey RS, Hall DA, Plack CJ, Francis ST. Comparison of continuous sampling with active noise cancelation and sparse sampling for cortical and subcortical auditory functional MRI. Magn Reson Med 2021; 86:2577-2588. [PMID: 34196020 DOI: 10.1002/mrm.28902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/01/2021] [Accepted: 06/04/2021] [Indexed: 11/06/2022]
Abstract
PURPOSE Detecting sound-related activity using functional MRI requires the auditory stimulus to be more salient than the intense background scanner acoustic noise. Various strategies can reduce the impact of scanner acoustic noise, including "sparse" temporal sampling with single/clustered acquisitions providing intervals without any background scanner acoustic noise, or active noise cancelation (ANC) during "continuous" temporal sampling, which generates an acoustic signal that adds destructively to the scanner acoustic noise, substantially reducing the acoustic energy at the participant's eardrum. Furthermore, multiband functional MRI allows multiple slices to be collected simultaneously, thereby reducing scanner acoustic noise in a given sampling period. METHODS Isotropic multiband functional MRI (1.5 mm) with sparse sampling (effective TR = 9000 ms, acquisition duration = 1962 ms) and continuous sampling (TR = 2000 ms) with ANC were compared in 15 normally hearing participants. A sustained broadband noise stimulus was presented to drive activation of both sustained and transient auditory responses within subcortical and cortical auditory regions. RESULTS Robust broadband noise-related activity was detected throughout the auditory pathways. Continuous sampling with ANC was found to give a statistically significant advantage over sparse sampling for the detection of the transient (onset) stimulus responses, particularly in the auditory cortex (P < .001) and inferior colliculus (P < .001), whereas gains provided by sparse over continuous ANC for detecting offset and sustained responses were marginal (p ~ 0.05 in superior olivary complex, inferior colliculus, medial geniculate body, and auditory cortex). CONCLUSIONS Sparse and continuous ANC multiband functional MRI protocols provide differing advantages for observing the transient (onset and offset) and sustained stimulus responses.
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Affiliation(s)
- Rebecca S Dewey
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.,National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,Hearing Sciences, Division of Mental Health and Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Deborah A Hall
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,Hearing Sciences, Division of Mental Health and Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom.,Heriot-Watt University Malaysia, Putrajaya, Malaysia
| | - Christopher J Plack
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom.,National Institute for Health Research Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom.,Department of Psychology, Lancaster University, Lancaster, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
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Burley CV, Francis ST, Thomas KN, Whittaker AC, Lucas SJE, Mullinger KJ. Contrasting Measures of Cerebrovascular Reactivity Between MRI and Doppler: A Cross-Sectional Study of Younger and Older Healthy Individuals. Front Physiol 2021; 12:656746. [PMID: 33912073 PMCID: PMC8072486 DOI: 10.3389/fphys.2021.656746] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular reactivity (CVR) is used as an outcome measure of brain health. Traditionally, lower CVR is associated with ageing, poor fitness and brain-related conditions (e.g. stroke, dementia). Indeed, CVR is suggested as a biomarker for disease risk. However, recent findings report conflicting associations between ageing or fitness and CVR measures. Inconsistent findings may relate to different neuroimaging modalities used, which include transcranial Doppler (TCD) and blood-oxygen-level-dependant (BOLD) contrast magnetic resonance imaging (MRI). We assessed the relationship between CVR metrics derived from two common imaging modalities, TCD and BOLD MRI, within the same individuals and with expected significant differences (i.e., younger vs. older) to maximise the expected spread in measures. We conducted two serial studies using TCD- and MRI-derived measures of CVR (via inspired 5% CO2 in air). Study 1 compared 20 younger (24 ± 7 years) with 15 older (66 ± 7 years) participants, Study 2 compared 10 younger (22 ± 2 years) with 10 older (72 ± 4 years) participants. Combining the main measures across studies, no significant correlation (r = 0.15, p = 0.36) was observed between individual participant TCD- and BOLD-CVR measures. Further, these measures showed differential effects between age groups; with TCD-CVR higher in the older compared to younger group (4 ± 1 vs. 3 ± 1 %MCAv/mmHg P ET CO2; p < 0.05, Hedges' g = 0.75), whereas BOLD-CVR showed no difference (p = 0.104, Hedges' g = 0.38). In Study 2 additional measures were obtained to understand the origin of the discrepancy: phase contrast angiography (PCA) MRI of the middle cerebral artery, showed a significantly lower blood flow (but not velocity) CVR response in older compared with younger participants (p > 0.05, Hedges' g = 1.08). The PCA CVR metrics did not significantly correlate with the BOLD- or TCD-CVR measures. The differing CVR observations between imaging modalities were despite expected, correlated (r = 0.62-0.82), age-related differences in resting CBF measures across modalities. Taken together, findings across both studies show no clear relationship between TCD- and BOLD-CVR measures. We hypothesize that CVR differences between imaging modalities are in part due to the aspects of the vascular tree that are assessed (TCD:arteries; BOLD:venules/veins). Further work is needed to understand the between-modality CVR response differences, but caution is needed when comparing CVR metrics derived from different imaging modalities.
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Affiliation(s)
- Claire V. Burley
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Dementia Centre for Research Collaboration, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Kate N. Thomas
- Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Anna C. Whittaker
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Samuel J. E. Lucas
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | - Karen J. Mullinger
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
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16
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Sanchez Panchuelo RM, Mougin O, Turner R, Francis ST. Quantitative T1 mapping using multi-slice multi-shot inversion recovery EPI. Neuroimage 2021; 234:117976. [PMID: 33781969 PMCID: PMC8204273 DOI: 10.1016/j.neuroimage.2021.117976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/27/2021] [Accepted: 03/13/2021] [Indexed: 11/12/2022] Open
Abstract
An efficient multi-slice inversion–recovery EPI (MS-IR-EPI) sequence for fast, high spatial resolution, quantitative T1 mapping is presented, using a segmented simultaneous multi-slice acquisition, combined with slice order shifting across multiple acquisitions. The segmented acquisition minimises the effective TE and readout duration compared to a single-shot EPI scheme, reducing geometric distortions to provide high quality T1 maps with a narrow point-spread function. The precision and repeatability of MS-IR-EPI T1 measurements are assessed using both T1-calibrated and T2-calibrated ISMRM/NIST phantom spheres at 3 and 7 T and compared with single slice IR and MP2RAGE methods. Magnetization transfer (MT) effects of the spectrally-selective fat-suppression (FS) pulses required for in vivo imaging are shown to shorten the measured in-vivo T1 values. We model the effect of these fat suppression pulses on T1 measurements and show that the model can remove their MT contribution from the measured T1, thus providing accurate T1 quantification. High spatial resolution T1 maps of the human brain generated with MS-IR-EPI at 7 T are compared with those generated with the widely implemented MP2RAGE sequence. Our MS-IR-EPI sequence provides high SNR per unit time and sharper T1 maps than MP2RAGE, demonstrating the potential for ultra-high resolution T1 mapping and the improved discrimination of functionally relevant cortical areas in the human brain.
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Affiliation(s)
- Rosa M Sanchez Panchuelo
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom.
| | - Olivier Mougin
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Robert Turner
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom
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Daniel AJ, Buchanan CE, Allcock T, Scerri D, Cox EF, Prestwich BL, Francis ST. Automated renal segmentation in healthy and chronic kidney disease subjects using a convolutional neural network. Magn Reson Med 2021; 86:1125-1136. [PMID: 33755256 DOI: 10.1002/mrm.28768] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/22/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Total kidney volume (TKV) is an important measure in renal disease detection and monitoring. We developed a fully automated method to segment the kidneys from T2 -weighted MRI to calculate TKV of healthy control (HC) and chronic kidney disease (CKD) patients. METHODS This automated method uses machine learning, specifically a 2D convolutional neural network (CNN), to accurately segment the left and right kidneys from T2 -weighted MRI data. The data set consisted of 30 HC subjects and 30 CKD patients. The model was trained on 50 manually defined HC and CKD kidney segmentations. The model was subsequently evaluated on 50 test data sets, comprising data from 5 HCs and 5 CKD patients each scanned 5 times in a scan session to enable comparison of the precision of the CNN and manual segmentation of kidneys. RESULTS The unseen test data processed by the 2D CNN had a mean Dice score of 0.93 ± 0.01. The difference between manual and automatically computed TKV was 1.2 ± 16.2 mL with a mean surface distance of 0.65 ± 0.21 mm. The variance in TKV measurements from repeat acquisitions on the same subject was significantly lower using the automated method compared to manual segmentation of the kidneys. CONCLUSION The 2D CNN method provides fully automated segmentation of the left and right kidney and calculation of TKV in <10 s on a standard office computer, allowing high data throughput and is a freely available executable.
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Affiliation(s)
- Alexander J Daniel
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Thomas Allcock
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Daniel Scerri
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Benjamin L Prestwich
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
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Eldeghaidy S, Yang Q, Abualait T, Williamson AM, Hort J, Francis ST. Thermal taster status: Temperature modulation of cortical response to sweetness perception. Physiol Behav 2021; 230:113266. [PMID: 33246000 DOI: 10.1016/j.physbeh.2020.113266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 10/22/2022]
Abstract
Temperature is known to impact taste perception, but its reported effect on sweet taste perception in humans is inconsistent. Here, we assess whether thermal taste phenotype alters the temperature modulation of the brains' response to sweet samples and sweet taste perception. Participants (n = 24 balanced for thermal tasters (TT) and thermal non-tasters (TnT), 25 ± 7 years (mean ± SD), 10 males) underwent a thermal taste phenotyping session to study responses to cooling and warming of the tongue using a thermode. In a separate session, functional Magnetic Resonance Images (fMRI) were collected during sweet samples (87 mM sucrose) delivery at two temperatures ('cold' (5 ± 2 °C) and 'ambient' (20 ± 2 °C)) and the perceived sweetness intensity rated.In the phenotyping session, TTs had heightened perceptual temperature sensitivity to cooling and warming of the tongue using a thermode compared to TnTs. Although there was no significant effect during the fMRI session, the fMRI response to the 'cold sweet' sample across all participants was significantly increased in anterior insula/frontal operculum and mid-insula compared to the 'ambient sweet' sample, likely to reflect the perceptual difference to temperature rather than taste perception. TTs showed significantly increased fMRI activation patterns compared with TnTs and an interaction effect between thermal taster status and sample temperature, with TTs showing selectively greater cortical responses to 'cold sweet' samples compared to TnTs in somatosensory regions (SI and SII).The increase in cortical activation in somatosensory cortices to the 'cold sweet' stimulus correlated with perceptual ratings of temperature sensitivity to the thermode. The results highlight the importance of investigating the effects of thermal taster phenotype across a range of temperatures representing the reality of consumer consumption to beverages.
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Affiliation(s)
- Sally Eldeghaidy
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; Division of Food, Nutrition & Dietetics, and Future Food Beacon, School of Biosciences, University of Nottingham, Loughborough LE12 5RD, United Kingdom
| | - Qian Yang
- Sensory Science Centre, School of Biosciences, Sutton Bonington Campus, University of Nottingham, Loughborough LE12 5RD, United Kingdom
| | - Turki Abualait
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; College of Applied Medical Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Joanne Hort
- Sensory Science Centre, School of Biosciences, Sutton Bonington Campus, University of Nottingham, Loughborough LE12 5RD, United Kingdom; Feast & Riddet Institute, Massey University, Palmerston North 4410, New Zealand
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.
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Buchanan CE, Mahmoud H, Cox EF, McCulloch T, Prestwich BL, Taal MW, Selby NM, Francis ST. Quantitative assessment of renal structural and functional changes in chronic kidney disease using multi-parametric magnetic resonance imaging. Nephrol Dial Transplant 2020; 35:955-964. [PMID: 31257440 PMCID: PMC7282828 DOI: 10.1093/ndt/gfz129] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/13/2019] [Indexed: 12/20/2022] Open
Abstract
Background Multi-parametric magnetic resonance imaging (MRI) provides the potential for a more comprehensive non-invasive assessment of organ structure and function than individual MRI measures, but has not previously been comprehensively evaluated in chronic kidney disease (CKD). Methods We performed multi-parametric renal MRI in persons with CKD (n = 22, 61 ± 24 years) who had a renal biopsy and measured glomerular filtration rate (mGFR), and matched healthy volunteers (HV) (n = 22, 61 ± 25 years). Longitudinal relaxation time (T1), diffusion-weighted imaging, renal blood flow (phase contrast MRI), cortical perfusion (arterial spin labelling) and blood-oxygen-level-dependent relaxation rate (R2*) were evaluated. Results MRI evidenced excellent reproducibility in CKD (coefficient of variation <10%). Significant differences between CKD and HVs included cortical and corticomedullary difference (CMD) in T1, cortical and medullary apparent diffusion coefficient (ADC), renal artery blood flow and cortical perfusion. MRI measures correlated with kidney function in a combined CKD and HV analysis: estimated GFR correlated with cortical T1 (r = −0.68), T1 CMD (r = −0.62), cortical (r = 0.54) and medullary ADC (r = 0.49), renal artery flow (r = 0.78) and cortical perfusion (r = 0.81); log urine protein to creatinine ratio (UPCR) correlated with cortical T1 (r = 0.61), T1 CMD (r = 0.61), cortical (r = −0.45) and medullary ADC (r = −0.49), renal artery flow (r = −0.72) and cortical perfusion (r = −0.58). MRI measures (cortical T1 and ADC, T1 and ADC CMD, cortical perfusion) differed between low/high interstitial fibrosis groups at 30–40% fibrosis threshold. Conclusion Comprehensive multi-parametric MRI is reproducible and correlates well with available measures of renal function and pathology. Larger longitudinal studies are warranted to evaluate its potential to stratify prognosis and response to therapy in CKD.
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Affiliation(s)
- Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Huda Mahmoud
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | | | - Benjamin L Prestwich
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Panchuelo RMS, Eldeghaidy S, Marshall A, McGlone F, Francis ST, Favorov O. A nociresponsive specific area of human somatosensory cortex within BA3a: BA3c? Neuroimage 2020; 221:117187. [PMID: 32711068 PMCID: PMC7762820 DOI: 10.1016/j.neuroimage.2020.117187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 01/03/2023] Open
Abstract
It is well recognized that in primates, including humans, noxious body stimulation evokes a neural response in the posterior bank of the central sulcus, in Brodmann cytoarchitectonic subdivisions 3b and 1 of the primary somatosensory cortex. This response is associated with the 1st/sharp pain and contributes to sensory discriminative aspects of pain perception and spatial localization of the noxious stimulus. However, neurophysiological studies in New World monkeys predict that in humans noxious stimulation also evokes a separate neural response-mediated by C-afferent drive and associated with the 2nd/burning pain-in the depth of the central sulcus in Brodmann area 3a (BA3a) at the transition between the somatosensory and motor cortices. To evoke such a response, it is necessary to use multi-second duration noxious stimulation, rather than brief laser pulses. Given the limited human pain-imaging literature on cortical responses induced by C-nociceptive input specifically within BA3a, here we used high spatial resolution 7T fMRI to study the response to thermonoxious skin stimulation. We observed the predicted response of BA3a in the depth of the central sulcus in five human volunteers. Review of the available evidence suggests that the nociresponsive region in the depth of the central sulcus is a structurally and functionally distinct cortical area that should not be confused with proprioceptive BA3a. It is most likely engaged in interoception and control of the autonomic nervous system, and contributes to the sympathetic response to noxious stimulation, arguably the most intolerable aspect of pain experience. Ablation of this region has been shown to reduce pain sensibility and might offer an effective means of ameliorating some pathological pain conditions.
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Affiliation(s)
- Rosa M Sanchez Panchuelo
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Sally Eldeghaidy
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK; Future Food Beacon, School of Biosciences, University of Nottingham, Nottingham, UK
| | - Andrew Marshall
- Institute of Aging and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Francis McGlone
- School of natural Science and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK; NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Oleg Favorov
- Department of Biomedical Engineering, University of North Carolina, CB #7575, Chapel Hill, NC 27599, USA.
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21
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Bradley CR, Bragg DD, Cox EF, El-Sharkawy AM, Buchanan CE, Chowdhury AH, Macdonald IA, Francis ST, Lobo DN. A randomized, controlled, double-blind crossover study on the effects of isoeffective and isovolumetric intravenous crystalloid and gelatin on blood volume, and renal and cardiac hemodynamics. Clin Nutr 2020; 39:2070-2079. [PMID: 31668721 PMCID: PMC7359406 DOI: 10.1016/j.clnu.2019.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/09/2019] [Accepted: 09/30/2019] [Indexed: 12/01/2022]
Abstract
BACKGROUND & AIMS Blood volume expanding properties of colloids are superior to crystalloids. In addition to oncotic/osmotic properties, the electrolyte composition of infusions may have important effects on visceral perfusion, with infusions containing supraphysiological chloride causing hyperchloremic acidosis and decreased renal blood flow. In this non-inferiority study, a validated healthy human subject model was used to compare effects of colloid (4% succinylated gelatin) and crystalloid fluid regimens on blood volume, renal function, and cardiac output. METHODS Healthy male participants were given infusions over 60 min > 7 days apart in a randomized, crossover manner. Reference arm (A): 1.5 L of Sterofundin ISO, isoeffective arm (B): 0.5 L of 4% Gelaspan®, isovolumetric arm (C): 0.5 L of 4% Gelaspan® and 1 L of Sterofundin ISO (all B. Braun, Melsungen, Germany). Participants were studied over 240 min. Changes in blood volume were calculated from changes in weight and hematocrit. Renal volume, renal artery blood flow (RABF), renal cortex perfusion and diffusion, and cardiac index were measured with magnetic resonance imaging. RESULTS Ten of 12 males [mean (SE) age 23.9 (0.8) years] recruited, completed the study. Increase in body weight and extracellular fluid volume were significantly less after infusion B than infusions A and C, but changes in blood volume did not significantly differ between infusions. All infusions increased renal volume, with no significant differences between infusions. There was no significant difference in RABF across the infusion time course or between infusion types. Renal cortex perfusion decreased during the infusion (mean 18% decrease from baseline), with no significant difference between infusions. There was a trend for increased renal cortex diffusion (4.2% increase from baseline) for the crystalloid infusion. All infusions led to significant increases in cardiac index. CONCLUSIONS A smaller volume of colloid (4% succinylated gelatin) was as effective as a larger volume of crystalloid at expanding blood volume, increasing cardiac output and changing renal function. Significantly less interstitial space expansion occurred with the colloid. TRIAL REGISTRATION The protocol was registered with the European Union Drug Regulating Authorities Clinical Trials Database (https://eudract.ema.europa.eu) (EudraCT No. 2013-003260-32).
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Affiliation(s)
- Christopher R Bradley
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Sir Peter Mansfield Imaging Centre, University Park, University of Nottingham, NG7 2RD, UK
| | - Damian D Bragg
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Eleanor F Cox
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Sir Peter Mansfield Imaging Centre, University Park, University of Nottingham, NG7 2RD, UK
| | - Ahmed M El-Sharkawy
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, University Park, University of Nottingham, NG7 2RD, UK
| | - Abeed H Chowdhury
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Ian A Macdonald
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Susan T Francis
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Sir Peter Mansfield Imaging Centre, University Park, University of Nottingham, NG7 2RD, UK
| | - Dileep N Lobo
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
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22
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Villa G, Ringgaard S, Hermann I, Noble R, Brambilla P, Khatir DS, Zöllner FG, Francis ST, Selby NM, Remuzzi A, Caroli A. Correction to: Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper. MAGMA 2020; 33:747. [PMID: 32529448 PMCID: PMC7502060 DOI: 10.1007/s10334-020-00849-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The article Phase‑contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper, written by Giulia Villa, Steffen Ringgaard, Ingo Hermann, Rebecca Noble, Paolo Brambilla, Dinah S. Khatir, Frank G. Zöllner, Susan T. Francis, Nicholas M. Selby, Andrea Remuzzi and Anna Caroli, was originally published electronically on the publisher's internet portal on 17 August 2019 without open access.
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Affiliation(s)
- Giulia Villa
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Steffen Ringgaard
- MR Center, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Ingo Hermann
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Rebecca Noble
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Paolo Brambilla
- Department of Diagnostic Radiology, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
| | - Dinah S Khatir
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Andrea Remuzzi
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.,Department of Management, Information and Production Engineering, University of Bergamo, Dalmine, BG, Italy
| | - Anna Caroli
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy.
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23
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Umeh A, Kumar J, Francis ST, Liddle PF, Palaniyappan L. Global fMRI signal at rest relates to symptom severity in schizophrenia. Schizophr Res 2020; 220:281-282. [PMID: 32222349 DOI: 10.1016/j.schres.2020.03.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/09/2020] [Accepted: 03/18/2020] [Indexed: 11/25/2022]
Affiliation(s)
| | - Jyothika Kumar
- Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, United Kingdom; Precision Imaging, University of Nottingham, Nottingham, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Peter F Liddle
- Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Lena Palaniyappan
- Department of Psychiatry, University of Western Ontario, London, Ontario, Canada; Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada.
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24
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Buchanan CE, Mahmoud H, Cox EF, McCulloch T, Prestwich BL, Taal MW, Selby NM, Francis ST. Quantitative assessment of renal structural and functional changes in chronic kidney disease using multi-parametric magnetic resonance imaging. Nephrol Dial Transplant 2020. [PMID: 31257440 DOI: 10.1093/ndt/gfz129/5525254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Multi-parametric magnetic resonance imaging (MRI) provides the potential for a more comprehensive non-invasive assessment of organ structure and function than individual MRI measures, but has not previously been comprehensively evaluated in chronic kidney disease (CKD). METHODS We performed multi-parametric renal MRI in persons with CKD (n = 22, 61 ± 24 years) who had a renal biopsy and measured glomerular filtration rate (mGFR), and matched healthy volunteers (HV) (n = 22, 61 ± 25 years). Longitudinal relaxation time (T1), diffusion-weighted imaging, renal blood flow (phase contrast MRI), cortical perfusion (arterial spin labelling) and blood-oxygen-level-dependent relaxation rate (R2*) were evaluated. RESULTS MRI evidenced excellent reproducibility in CKD (coefficient of variation <10%). Significant differences between CKD and HVs included cortical and corticomedullary difference (CMD) in T1, cortical and medullary apparent diffusion coefficient (ADC), renal artery blood flow and cortical perfusion. MRI measures correlated with kidney function in a combined CKD and HV analysis: estimated GFR correlated with cortical T1 (r = -0.68), T1 CMD (r = -0.62), cortical (r = 0.54) and medullary ADC (r = 0.49), renal artery flow (r = 0.78) and cortical perfusion (r = 0.81); log urine protein to creatinine ratio (UPCR) correlated with cortical T1 (r = 0.61), T1 CMD (r = 0.61), cortical (r = -0.45) and medullary ADC (r = -0.49), renal artery flow (r = -0.72) and cortical perfusion (r = -0.58). MRI measures (cortical T1 and ADC, T1 and ADC CMD, cortical perfusion) differed between low/high interstitial fibrosis groups at 30-40% fibrosis threshold. CONCLUSION Comprehensive multi-parametric MRI is reproducible and correlates well with available measures of renal function and pathology. Larger longitudinal studies are warranted to evaluate its potential to stratify prognosis and response to therapy in CKD.
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Affiliation(s)
- Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Huda Mahmoud
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | | | - Benjamin L Prestwich
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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25
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Bane O, Mendichovszky IA, Milani B, Dekkers IA, Deux JF, Eckerbom P, Grenier N, Hall ME, Inoue T, Laustsen C, Lerman LO, Liu C, Morrell G, Pedersen M, Pruijm M, Sadowski EA, Seeliger E, Sharma K, Thoeny H, Vermathen P, Wang ZJ, Serafin Z, Zhang JL, Francis ST, Sourbron S, Pohlmann A, Fain SB, Prasad PV. Consensus-based technical recommendations for clinical translation of renal BOLD MRI. MAGMA 2020; 33:199-215. [PMID: 31768797 PMCID: PMC7021747 DOI: 10.1007/s10334-019-00802-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 01/08/2023]
Abstract
Harmonization of acquisition and analysis protocols is an important step in the validation of BOLD MRI as a renal biomarker. This harmonization initiative provides technical recommendations based on a consensus report with the aim to move towards standardized protocols that facilitate clinical translation and comparison of data across sites. We used a recently published systematic review paper, which included a detailed summary of renal BOLD MRI technical parameters and areas of investigation in its supplementary material, as the starting point in developing the survey questionnaires for seeking consensus. Survey data were collected via the Delphi consensus process from 24 researchers on renal BOLD MRI exam preparation, data acquisition, data analysis, and interpretation. Consensus was defined as ≥ 75% unanimity in response. Among 31 survey questions, 14 achieved consensus resolution, 12 showed clear respondent preference (65-74% agreement), and 5 showed equal (50/50%) split in opinion among respondents. Recommendations for subject preparation, data acquisition, processing and reporting are given based on the survey results and review of the literature. These technical recommendations are aimed towards increased inter-site harmonization, a first step towards standardization of renal BOLD MRI protocols across sites. We expect this to be an iterative process updated dynamically based on progress in the field.
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Affiliation(s)
- Octavia Bane
- BioMedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | - Bastien Milani
- Center for BioMedical Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ilona A Dekkers
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jean-Francois Deux
- Department of Radiology, Groupe Hospitalier Henri Mondor, Créteil, France
| | - Per Eckerbom
- Department of Radiology, Institution for Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Nicolas Grenier
- Department of Radiology, Université de Bordeaux, CHU de Bordeaux, Bordeaux, France
| | - Michael E Hall
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Tsutomu Inoue
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Christoffer Laustsen
- The MR Research Center Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Chunlei Liu
- Electrical Engineering and Computer Science, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Glen Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Michael Pedersen
- Department of Clinical Medicine-Comparative Medicine Lab, Aarhus University Hospital, Aarhus, Denmark
| | - Menno Pruijm
- Nephrology and Hypertension Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Elizabeth A Sadowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Erdmann Seeliger
- Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Harriet Thoeny
- Department of Radiology, Hôpital Cantonal Fribourgois, University of Fribourg, Fribourg, Switzerland
| | - Peter Vermathen
- Departments for BioMedical Research and Radiology, Inselspital, Universitaetspital Bern, Bern, Switzerland
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco Medical Center, San Francisco, CA, USA
| | - Zbigniew Serafin
- Department of Radiology, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
| | - Jeff L Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan T Francis
- Sir Peter Mansfield Centre, University of Notthingham, Notthingham, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sean B Fain
- Departments of Biomedical Engineering, Radiology, and Medical Physics, University of Wisconsin, Madison, WI, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA.
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26
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Nery F, Buchanan CE, Harteveld AA, Odudu A, Bane O, Cox EF, Derlin K, Gach HM, Golay X, Gutberlet M, Laustsen C, Ljimani A, Madhuranthakam AJ, Pedrosa I, Prasad PV, Robson PM, Sharma K, Sourbron S, Taso M, Thomas DL, Wang DJJ, Zhang JL, Alsop DC, Fain SB, Francis ST, Fernández-Seara MA. Consensus-based technical recommendations for clinical translation of renal ASL MRI. MAGMA 2019. [PMID: 31833014 DOI: 10.1007/s10334‐019‐00800‐z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies. METHODS An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting. RESULTS Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model. DISCUSSION This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding.
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Affiliation(s)
- Fabio Nery
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Anita A Harteveld
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Aghogho Odudu
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Octavia Bane
- Translational and Molecular Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Katja Derlin
- Department of Radiology, Hannover Medical School, Hannover, Germany
| | - H Michael Gach
- Departments of Radiation Oncology, Radiology, and Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Xavier Golay
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Marcel Gutberlet
- Department of Radiology, Hannover Medical School, Hannover, Germany
| | - Christoffer Laustsen
- MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Alexandra Ljimani
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ananth J Madhuranthakam
- Department of Radiology and Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ivan Pedrosa
- Department of Radiology and Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA
| | - Philip M Robson
- Translational and Molecular Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Manuel Taso
- Division of MRI Research, Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - David L Thomas
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Danny J J Wang
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Jeff L Zhang
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - David C Alsop
- Division of MRI Research, Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Sean B Fain
- Departments of Medical Physics, Radiology, and Biomedical Engineering, University of Wisconsin, Madison, Madison, USA
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Nery F, Buchanan CE, Harteveld AA, Odudu A, Bane O, Cox EF, Derlin K, Gach HM, Golay X, Gutberlet M, Laustsen C, Ljimani A, Madhuranthakam AJ, Pedrosa I, Prasad PV, Robson PM, Sharma K, Sourbron S, Taso M, Thomas DL, Wang DJJ, Zhang JL, Alsop DC, Fain SB, Francis ST, Fernández-Seara MA. Consensus-based technical recommendations for clinical translation of renal ASL MRI. MAGMA 2019; 33:141-161. [PMID: 31833014 PMCID: PMC7021752 DOI: 10.1007/s10334-019-00800-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022]
Abstract
Objectives This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies. Methods An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting. Results Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model. Discussion This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding. Electronic supplementary material The online version of this article (10.1007/s10334-019-00800-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fabio Nery
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Anita A Harteveld
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Aghogho Odudu
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Octavia Bane
- Translational and Molecular Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Katja Derlin
- Department of Radiology, Hannover Medical School, Hannover, Germany
| | - H Michael Gach
- Departments of Radiation Oncology, Radiology, and Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Xavier Golay
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Marcel Gutberlet
- Department of Radiology, Hannover Medical School, Hannover, Germany
| | - Christoffer Laustsen
- MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Alexandra Ljimani
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ananth J Madhuranthakam
- Department of Radiology and Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ivan Pedrosa
- Department of Radiology and Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA
| | - Philip M Robson
- Translational and Molecular Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Manuel Taso
- Division of MRI Research, Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - David L Thomas
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Danny J J Wang
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Jeff L Zhang
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - David C Alsop
- Division of MRI Research, Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Sean B Fain
- Departments of Medical Physics, Radiology, and Biomedical Engineering, University of Wisconsin, Madison, Madison, USA
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Bane O, Mendichovszky IA, Milani B, Dekkers IA, Deux JF, Eckerbom P, Grenier N, Hall ME, Inoue T, Laustsen C, Lerman LO, Liu C, Morrell G, Pedersen M, Pruijm M, Sadowski EA, Seeliger E, Sharma K, Thoeny H, Vermathen P, Wang ZJ, Serafin Z, Zhang JL, Francis ST, Sourbron S, Pohlmann A, Fain SB, Prasad PV. Consensus-based technical recommendations for clinical translation of renal BOLD MRI. MAGMA 2019. [PMID: 31768797 DOI: 10.1007/s10334‐019‐00802‐x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Harmonization of acquisition and analysis protocols is an important step in the validation of BOLD MRI as a renal biomarker. This harmonization initiative provides technical recommendations based on a consensus report with the aim to move towards standardized protocols that facilitate clinical translation and comparison of data across sites. We used a recently published systematic review paper, which included a detailed summary of renal BOLD MRI technical parameters and areas of investigation in its supplementary material, as the starting point in developing the survey questionnaires for seeking consensus. Survey data were collected via the Delphi consensus process from 24 researchers on renal BOLD MRI exam preparation, data acquisition, data analysis, and interpretation. Consensus was defined as ≥ 75% unanimity in response. Among 31 survey questions, 14 achieved consensus resolution, 12 showed clear respondent preference (65-74% agreement), and 5 showed equal (50/50%) split in opinion among respondents. Recommendations for subject preparation, data acquisition, processing and reporting are given based on the survey results and review of the literature. These technical recommendations are aimed towards increased inter-site harmonization, a first step towards standardization of renal BOLD MRI protocols across sites. We expect this to be an iterative process updated dynamically based on progress in the field.
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Affiliation(s)
- Octavia Bane
- BioMedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | - Bastien Milani
- Center for BioMedical Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ilona A Dekkers
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jean-Francois Deux
- Department of Radiology, Groupe Hospitalier Henri Mondor, Créteil, France
| | - Per Eckerbom
- Department of Radiology, Institution for Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Nicolas Grenier
- Department of Radiology, Université de Bordeaux, CHU de Bordeaux, Bordeaux, France
| | - Michael E Hall
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Tsutomu Inoue
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Christoffer Laustsen
- The MR Research Center Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Chunlei Liu
- Electrical Engineering and Computer Science, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Glen Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Michael Pedersen
- Department of Clinical Medicine-Comparative Medicine Lab, Aarhus University Hospital, Aarhus, Denmark
| | - Menno Pruijm
- Nephrology and Hypertension Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Elizabeth A Sadowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Erdmann Seeliger
- Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Harriet Thoeny
- Department of Radiology, Hôpital Cantonal Fribourgois, University of Fribourg, Fribourg, Switzerland
| | - Peter Vermathen
- Departments for BioMedical Research and Radiology, Inselspital, Universitaetspital Bern, Bern, Switzerland
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco Medical Center, San Francisco, CA, USA
| | - Zbigniew Serafin
- Department of Radiology, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
| | - Jeff L Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan T Francis
- Sir Peter Mansfield Centre, University of Notthingham, Notthingham, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sean B Fain
- Departments of Biomedical Engineering, Radiology, and Medical Physics, University of Wisconsin, Madison, WI, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA.
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Dewey RS, Francis ST, Guest H, Prendergast G, Millman RE, Plack CJ, Hall DA. The association between subcortical and cortical fMRI and lifetime noise exposure in listeners with normal hearing thresholds. Neuroimage 2019; 204:116239. [PMID: 31586673 PMCID: PMC6905154 DOI: 10.1016/j.neuroimage.2019.116239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/07/2019] [Accepted: 09/30/2019] [Indexed: 10/26/2022] Open
Abstract
In animal models, exposure to high noise levels can cause permanent damage to hair-cell synapses (cochlear synaptopathy) for high-threshold auditory nerve fibers without affecting sensitivity to quiet sounds. This has been confirmed in several mammalian species, but the hypothesis that lifetime noise exposure affects auditory function in humans with normal audiometric thresholds remains unconfirmed and current evidence from human electrophysiology is contradictory. Here we report the auditory brainstem response (ABR), and both transient (stimulus onset and offset) and sustained functional magnetic resonance imaging (fMRI) responses throughout the human central auditory pathway across lifetime noise exposure. Healthy young individuals aged 25-40 years were recruited into high (n = 32) and low (n = 30) lifetime noise exposure groups, stratified for age, and balanced for audiometric threshold up to 16 kHz fMRI demonstrated robust broadband noise-related activity throughout the auditory pathway (cochlear nucleus, superior olivary complex, nucleus of the lateral lemniscus, inferior colliculus, medial geniculate body and auditory cortex). fMRI responses in the auditory pathway to broadband noise onset were significantly enhanced in the high noise exposure group relative to the low exposure group, differences in sustained fMRI responses did not reach significance, and no significant group differences were found in the click-evoked ABR. Exploratory analyses found no significant relationships between the neural responses and self-reported tinnitus or reduced sound-level tolerance (symptoms associated with synaptopathy). In summary, although a small effect, these fMRI results suggest that lifetime noise exposure may be associated with central hyperactivity in young adults with normal hearing thresholds.
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Affiliation(s)
- Rebecca S Dewey
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2RD, UK; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham, NG1 5DU, UK; Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, NG7 2UH, UK.
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2RD, UK.
| | - Hannah Guest
- Manchester Centre for Audiology and Deafness (ManCAD), University of Manchester, Manchester Academic Health Science Centre, M13 9PL, UK.
| | - Garreth Prendergast
- Manchester Centre for Audiology and Deafness (ManCAD), University of Manchester, Manchester Academic Health Science Centre, M13 9PL, UK.
| | - Rebecca E Millman
- Manchester Centre for Audiology and Deafness (ManCAD), University of Manchester, Manchester Academic Health Science Centre, M13 9PL, UK; National Institute for Health Research (NIHR) Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, M13 9WL, UK.
| | - Christopher J Plack
- Manchester Centre for Audiology and Deafness (ManCAD), University of Manchester, Manchester Academic Health Science Centre, M13 9PL, UK; National Institute for Health Research (NIHR) Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, M13 9WL, UK; Department of Psychology, Lancaster University, LA1 4YF, UK.
| | - Deborah A Hall
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham, NG1 5DU, UK; Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, NG7 2UH, UK; University of Nottingham Malaysia, Jalan Broga, 43500, Semeniyh, Selangor Darul Ehsan, Malaysia.
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Sokoliuk R, Mayhew SD, Aquino KM, Wilson R, Brookes MJ, Francis ST, Hanslmayr S, Mullinger KJ. Two Spatially Distinct Posterior Alpha Sources Fulfill Different Functional Roles in Attention. J Neurosci 2019; 39:7183-7194. [PMID: 31341028 PMCID: PMC6733553 DOI: 10.1523/jneurosci.1993-18.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 11/21/2022] Open
Abstract
Directing attention helps to extract relevant information and suppress distracters. Alpha brain oscillations (8-12 Hz) are crucial for this process, with power decreases facilitating processing of important information and power increases inhibiting brain regions processing irrelevant information. Evidence for this phenomenon arises from visual attention studies (Worden et al., 2000); however, the effect also exists in other modalities, including the somatosensory system (Haegens et al., 2011) and intersensory attention tasks (Foxe and Snyder, 2011). We investigated in human participants (10 females, 10 males) the role of alpha oscillations in focused (0/100%) versus divided (40/60%) attention, both across modalities (visual/somatosensory; Experiment 1) and within the same modality (visual domain: across hemifields; Experiment 2) while recording EEG over 128 scalp electrodes. In Experiment 1, participants divided their attention between visual and somatosensory modality to determine the temporal/spatial frequency of a target stimulus (vibrotactile stimulus/Gabor grating). In Experiment 2, participants divided attention between two visual hemifields to identify the orientation of a Gabor grating. In both experiments, prestimulus alpha power in visual areas decreased linearly with increasing attention to visual stimuli. In contrast, prestimulus alpha power in parietal areas was lower when attention was divided between modalities/hemifields compared with focused attention. These results suggest there are two alpha sources, one of which reflects the "visual spotlight of attention" and the other reflects attentional effort. To our knowledge, this is the first study to show that attention recruits two spatially distinct alpha sources in occipital and parietal brain regions, acting simultaneously but serving different functions in attention.SIGNIFICANCE STATEMENT Attention to one spatial location/sensory modality leads to power changes of alpha oscillations (∼10 Hz) with decreased power over regions processing relevant information and power increases to actively inhibit areas processing "to-be-ignored" information. Here, we used detailed source modeling to investigate EEG data recorded during separate unimodal (visual) and multimodal (visual and somatosensory) attention tasks. Participants either focused their attention on one modality/spatial location or directed it to both. We show for the first time two distinct alpha sources are active simultaneously but play different roles. A sensory (visual) alpha source was linearly modulated by attention representing the "visual spotlight of attention." By contrast, a parietal alpha source was modulated by attentional effort, showing lowest alpha power when attention was divided.
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Affiliation(s)
- Rodika Sokoliuk
- Centre for Human Brain Health, School of Psychology, University of Birmingham, B15 2TT, Edgbaston, Birmingham, United Kingdom,
| | - Stephen D Mayhew
- Centre for Human Brain Health, School of Psychology, University of Birmingham, B15 2TT, Edgbaston, Birmingham, United Kingdom
| | - Kevin M Aquino
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2QX, Nottingham, United Kingdom, and
- Monash University, 3800 Melbourne, Australia
| | - Ross Wilson
- Centre for Human Brain Health, School of Psychology, University of Birmingham, B15 2TT, Edgbaston, Birmingham, United Kingdom
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2QX, Nottingham, United Kingdom, and
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2QX, Nottingham, United Kingdom, and
| | - Simon Hanslmayr
- Centre for Human Brain Health, School of Psychology, University of Birmingham, B15 2TT, Edgbaston, Birmingham, United Kingdom
| | - Karen J Mullinger
- Centre for Human Brain Health, School of Psychology, University of Birmingham, B15 2TT, Edgbaston, Birmingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, NG7 2QX, Nottingham, United Kingdom, and
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Wilson R, Mullinger KJ, Francis ST, Mayhew SD. The relationship between negative BOLD responses and ERS and ERD of alpha/beta oscillations in visual and motor cortex. Neuroimage 2019; 199:635-650. [PMID: 31189075 DOI: 10.1016/j.neuroimage.2019.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/10/2019] [Accepted: 06/03/2019] [Indexed: 01/06/2023] Open
Abstract
Previous work has investigated the electrophysiological origins of the intra-modal (within the stimulated sensory cortex) negative BOLD fMRI response (NBR, decrease from baseline) but little attention has been paid to the origin of cross-modal NBRs, those in a different sensory cortex. In the current study we use simultaneous EEG-fMRI recordings to assess the neural correlates of both intra- and cross-modal responses to left-hemifield visual stimuli and right-hand motor tasks, and evaluate the balance of activation and deactivation between the visual and motor systems. Within- and between-subject covariations of EEG and fMRI responses to both tasks are assessed to determine how patterns of event-related desynchronization/synchronisation (ERD/ERS) of alpha/beta frequency oscillations relate to the NBR in the two sensory cortices. We show that both visual and motor tasks induce intra-modal NBR and cross-modal NBR (e.g. visual stimuli evoked NBRs in both visual and motor cortices). In the EEG data, bilateral intra-modal alpha/beta ERD were consistently observed to both tasks, whilst the cross-modal EEG response varied across subjects between alpha/beta ERD and ERS. Both the mean cross-modal EEG and fMRI response amplitudes showed a small increase in magnitude with increasing task intensity. In response to the visual stimuli, subjects displaying cross-modal ERS of motor beta power displayed a significantly larger magnitude of cross-modal NBR in motor cortex. However, in contrast to the motor stimuli, larger cross-modal ERD of visual alpha power was associated with larger cross-modal visual NBR. Single-trial correlation analysis provided further evidence of relationship between EEG signals and the NBR, motor cortex beta responses to motor tasks were significantly negatively correlated with cross-modal visual cortex NBR amplitude, and positively correlated with intra-modal motor cortex PBR. This study provides a new body of evidence that the coupling between BOLD and low-frequency (alpha/beta) sensory cortex EEG responses extends to cross-modal NBR.
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Affiliation(s)
- Ross Wilson
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK; SPMIC, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- SPMIC, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Stephen D Mayhew
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK.
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O'Neill GC, Watkins RH, Ackerley R, Barratt EL, Sengupta A, Asghar M, Sanchez Panchuelo RM, Brookes MJ, Glover PM, Wessberg J, Francis ST. Imaging human cortical responses to intraneural microstimulation using magnetoencephalography. Neuroimage 2019; 189:329-340. [PMID: 30639839 PMCID: PMC6435103 DOI: 10.1016/j.neuroimage.2019.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 01/02/2019] [Accepted: 01/08/2019] [Indexed: 01/25/2023] Open
Abstract
The sensation of touch in the glabrous skin of the human hand is conveyed by thousands of fast-conducting mechanoreceptive afferents, which can be categorised into four distinct types. The spiking properties of these afferents in the periphery in response to varied tactile stimuli are well-characterised, but relatively little is known about the spatiotemporal properties of the neural representations of these different receptor types in the human cortex. Here, we use the novel methodological combination of single-unit intraneural microstimulation (INMS) with magnetoencephalography (MEG) to localise cortical representations of individual touch afferents in humans, by measuring the extracranial magnetic fields from neural currents. We found that by assessing the modulation of the beta (13-30 Hz) rhythm during single-unit INMS, significant changes in oscillatory amplitude occur in the contralateral primary somatosensory cortex within and across a group of fast adapting type I mechanoreceptive afferents, which corresponded well to the induced response from matched vibrotactile stimulation. Combining the spatiotemporal specificity of MEG with the selective single-unit stimulation of INMS enables the interrogation of the central representations of different aspects of tactile afferent signalling within the human cortices. The fundamental finding that single-unit INMS ERD responses are robust and consistent with natural somatosensory stimuli will permit us to more dynamically probe the central nervous system responses in humans, to address questions about the processing of touch from the different classes of mechanoreceptive afferents and the effects of varying the stimulus frequency and patterning.
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Affiliation(s)
- George C O'Neill
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
| | - Roger H Watkins
- Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Rochelle Ackerley
- Department of Physiology, University of Gothenburg, Gothenburg, Sweden; Aix Marseille Univ, CNRS, LNSC (Laboratoire de Neurosciences Sensorielles et Cognitives - UMR 7260), Marseille, France
| | - Eleanor L Barratt
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Ayan Sengupta
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Michael Asghar
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | | | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Paul M Glover
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Johan Wessberg
- Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Wesolowski R, Blockley NP, Driver ID, Francis ST, Gowland PA. Coupling between cerebral blood flow and cerebral blood volume: Contributions of different vascular compartments. NMR Biomed 2019; 32:e4061. [PMID: 30657208 PMCID: PMC6492110 DOI: 10.1002/nbm.4061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
A better understanding of the coupling between changes in cerebral blood flow (CBF) and cerebral blood volume (CBV) is vital for furthering our understanding of the BOLD response. The aim of this study was to measure CBF-CBV coupling in different vascular compartments during neural activation. Three haemodynamic parameters were measured during a visual stimulus. Look-Locker flow-sensitive alternating inversion recovery was used to measure changes in CBF and arterial CBV (CBVa ) using sequence parameters optimized for each contrast. Changes in total CBV (CBVtot ) were measured using a gadolinium-based contrast agent technique. Haemodynamic changes were extracted from a region of interest based on voxels that were activated in the CBF experiments. The CBF-CBVtot coupling constant αtot was measured as 0.16 ± 0.14 and the CBF-CBVa coupling constant αa was measured as 0.65 ± 0.24. Using a two-compartment model of the vasculature (arterial and venous), the change in venous CBV (CBVv ) was predicted for an assumed value of baseline arterial and venous blood volume. These results will enhance the accuracy and reliability of applications that rely on models of the BOLD response, such as calibrated BOLD.
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Affiliation(s)
- Roman Wesolowski
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
- Medical Physics and ImagingUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUK
| | - Nicholas P. Blockley
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Ian D. Driver
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
- Cardiff University Brain Research Imaging Centre, School of PsychologyCardiff UniversityCardiffUK
| | - Susan T. Francis
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
| | - Penny A. Gowland
- Sir Peter Mansfield Imaging CentreUniversity of NottinghamNottinghamUK
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Aquino KM, Sokoliuk R, Pakenham DO, Sanchez-Panchuelo RM, Hanslmayr S, Mayhew SD, Mullinger KJ, Francis ST. Addressing challenges of high spatial resolution UHF fMRI for group analysis of higher-order cognitive tasks: An inter-sensory task directing attention between visual and somatosensory domains. Hum Brain Mapp 2018; 40:1298-1316. [PMID: 30430706 PMCID: PMC6865556 DOI: 10.1002/hbm.24450] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 10/05/2018] [Accepted: 10/12/2018] [Indexed: 01/20/2023] Open
Abstract
Functional MRI at ultra‐high field (UHF, ≥7 T) provides significant increases in BOLD contrast‐to‐noise ratio (CNR) compared with conventional field strength (3 T), and has been exploited for reduced field‐of‐view, high spatial resolution mapping of primary sensory areas. Applying these high spatial resolution methods to investigate whole brain functional responses to higher‐order cognitive tasks leads to a number of challenges, in particular how to perform robust group‐level statistical analyses. This study addresses these challenges using an inter‐sensory cognitive task which modulates top‐down attention at graded levels between the visual and somatosensory domains. At the individual level, highly focal functional activation to the task and task difficulty (modulated by attention levels) were detectable due to the high CNR at UHF. However, to assess group level effects, both anatomical and functional variability must be considered during analysis. We demonstrate the importance of surface over volume normalisation and the requirement of no spatial smoothing when assessing highly focal activity. Using novel group analysis on anatomically parcellated brain regions, we show that in higher cognitive areas (parietal and dorsal‐lateral‐prefrontal cortex) fMRI responses to graded attention levels were modulated quadratically, whilst in visual cortex and VIP, responses were modulated linearly. These group fMRI responses were not seen clearly using conventional second‐level GLM analyses, illustrating the limitations of a conventional approach when investigating such focal responses in higher cognitive regions which are more anatomically variable. The approaches demonstrated here complement other advanced analysis methods such as multivariate pattern analysis, allowing UHF to be fully exploited in cognitive neuroscience.
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Affiliation(s)
- Kevin M Aquino
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.,Brain and Mental Health Laboratory, Monash University, Clayton, Australia.,School of Physics, University of Sydney, Sydney, Australia
| | - Rodika Sokoliuk
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Daisie O Pakenham
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Rosa Maria Sanchez-Panchuelo
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Simon Hanslmayr
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Stephen D Mayhew
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Karen J Mullinger
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.,Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
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Bradley CR, Cox EF, Scott RA, James MW, Kaye P, Aithal GP, Francis ST, Guha IN. Multi-organ assessment of compensated cirrhosis patients using quantitative magnetic resonance imaging. J Hepatol 2018; 69:1015-1024. [PMID: 29886155 DOI: 10.1016/j.jhep.2018.05.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS Advancing liver disease results in deleterious changes in a number of critical organs. The ability to measure structure, blood flow and tissue perfusion within multiple organs in a single scan has implications for determining the balance of benefit vs. harm for therapies. Our aim was to establish the feasibility of magnetic resonance imaging (MRI) to assess changes in Compensated Cirrhosis (CC), and relate this to disease severity and future liver-related outcomes (LROs). METHODS A total of 60 patients with CC, 40 healthy volunteers and 7 patients with decompensated cirrhosis were recruited. In a single scan session, MRI measures comprised phase-contrast MRI vessel blood flow, arterial spin labelling tissue perfusion, T1 longitudinal relaxation time, heart rate, cardiac index, and volume assessment of the liver, spleen and kidneys. We explored the association between MRI parameters and disease severity, analysing differences in baseline MRI parameters in the 11 (18%) patients with CC who experienced future LROs. RESULTS In the liver, compositional changes were reflected by increased T1 in progressive disease (p <0.001) and an increase in liver volume in CC (p = 0.006), with associated progressive reduction in liver (p <0.001) and splenic (p <0.001) perfusion. A significant reduction in renal cortex T1 and increase in cardiac index and superior mesenteric arterial blood flow was seen with increasing disease severity. Baseline liver T1 (p = 0.01), liver perfusion (p <0.01), and renal cortex T1 (p <0.01) were significantly different in patients with CC who subsequently developed negative LROs. CONCLUSIONS MRI enables the contemporaneous assessment of organs in liver cirrhosis in a single scan without the requirement for a contrast agent. MRI parameters of liver T1, renal T1, hepatic and splenic perfusion, and superior mesenteric arterial blood flow were related to the risk of LROs. LAY SUMMARY This study assesses the changes to structure, blood flow and perfusion that occur in the key organs (liver, spleen and kidney) associated with severe liver disease (Compensated Cirrhosis), using magnetic resonance imaging. The magnetic resonance imaging measures which changed with disease severity and were related to negative liver-related clinical outcomes are described.
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Affiliation(s)
- Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Robert A Scott
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Martin W James
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Phillip Kaye
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Guruprasad P Aithal
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK; Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Indra Neil Guha
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK; Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK.
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Cox EF, Palaniyappan N, Aithal GP, Guha IN, Francis ST. Using MRI to study the alterations in liver blood flow, perfusion, and oxygenation in response to physiological stress challenges: Meal, hyperoxia, and hypercapnia. J Magn Reson Imaging 2018; 49:1577-1586. [PMID: 30353969 DOI: 10.1002/jmri.26341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/29/2018] [Accepted: 08/29/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Noninvasive assessment of dynamic changes in liver blood flow, perfusion, and oxygenation using MRI may allow detection of subtle hemodynamic alterations in cirrhosis. PURPOSE To assess the feasibility of measuring dynamic liver blood flow, perfusion, and T2 * alterations in response to meal, hypercapnia, and hyperoxia challenges. STUDY TYPE Prospective. SUBJECTS Ten healthy volunteers (HV) and 10 patients with compensated cirrhosis (CC). FIELD STRENGTH/SEQUENCE 3T; phase contrast, arterial spin labeling, and T 2 * mapping. ASSESSMENT Dynamic changes in portal vein and hepatic artery blood flow (using phase contrast MRI), liver perfusion (using arterial spin labeling), and blood oxygenation ( T 2 * mapping) following a meal challenge (660 kcal), hyperoxia (target PET O2 of 500 mmHg), and hypercapnia (target increase PET CO2 of ∼6 mmHg). STATISTICAL TESTS Tests between baseline and each challenge were performed using a paired two-tailed t-test (parametric) or Wilcoxon-signed-ranks test (nonparametric). Repeatability and reproducibility were determined by the coefficient of variation (CoV). RESULTS Portal vein velocity increased following the meal (70 ± 9%, P < 0.001) and hypercapnic (7 (5-11)%, P = 0.029) challenge, while hepatic artery flow decreased (-30 ± 18%, P = 0.005) following the meal challenge in HV. In CC patients, portal vein velocity increased (37 ± 13%, P = 0.012) without the decrease in hepatic artery flow following the meal. In both groups, the meal increased liver perfusion (HV: 82 ± 50%, P < 0.0001; CC: 27 (16-42)%, P = 0.011) with faster arrival time of blood (HV: -54 (-56-30)%, P = 0.074; CC: -42 ± 32%, P = 0.005). In HVs, T 2 * increased after the meal and in response to hyperoxia, with a decrease in hypercapnia (6 ± 8% P = 0.052; 3 ± 5%, P = 0.075; -5 ± 6%, P = 0.073, respectively), but no change in CC patients. Baseline between-session CoV <15% for blood flow and <10% for T 2 * measures. DATA CONCLUSION Dynamic changes in liver perfusion, blood flow, and oxygenation following a meal, hyperoxic, and hypercapnic challenges can be measured using noninvasive MRI and potentially be used to stratify patients with cirrhosis. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1577-1586.
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Affiliation(s)
- Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham BRC, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Naaventhan Palaniyappan
- NIHR Nottingham BRC, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Guruprasad P Aithal
- NIHR Nottingham BRC, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - I Neil Guha
- NIHR Nottingham BRC, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham BRC, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
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Dury RJ, Falah Y, Gowland PA, Evangelou N, Bright MG, Francis ST. Ultra-high-field arterial spin labelling MRI for non-contrast assessment of cortical lesion perfusion in multiple sclerosis. Eur Radiol 2018; 29:2027-2033. [PMID: 30280247 PMCID: PMC6420612 DOI: 10.1007/s00330-018-5707-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 07/09/2018] [Accepted: 08/06/2018] [Indexed: 11/27/2022]
Abstract
Objectives To assess the feasibility of using an optimised ultra-high-field high-spatial-resolution low-distortion arterial spin labelling (ASL) MRI acquisition to measure focal haemodynamic pathology in cortical lesions (CLs) in multiple sclerosis (MS). Methods Twelve MS patients (eight female, mean age 50 years; range 35–64 years) gave informed consent and were scanned on a 7 Tesla Philips Achieva scanner. Perfusion data were collected at multiple post-labelling delay times using a single-slice flow-sensitive alternating inversion recovery ASL protocol with a balanced steady-state free precession readout scheme. CLs were identified using a high-resolution Phase-Sensitive Inversion Recovery (PSIR) scan. Significant differences in perfusion within CLs compared to immediately surrounding normal appearing grey matter (NAGMlocal) and total cortical normal appearing grey matter (NAGMcortical) were assessed using paired t-tests. Results Forty CLs were identified in PSIR scans that overlapped with the ASL acquisition coverage. After excluding lesions due to small size or intravascular contamination, 27 lesions were eligible for analysis. Mean perfusion was 40 ± 25 ml/100 g/min in CLs, 53 ± 12 ml/100 g/min in NAGMlocal, and 53 ± 8 ml/100 g/min in NAGMcortical. CL perfusion was significantly reduced by 23 ± 9% (mean ± SE, p = 0.013) and 26 ± 9% (p = 0.006) relative to NAGMlocal and NAGMcortical perfusion, respectively. Conclusion This is the first ASL MRI study quantifying CL perfusion in MS at 7 Tesla, demonstrating that an optimised ASL acquisition is sensitive to focal haemodynamic pathology previously observed using dynamic susceptibility contrast MRI. ASL requires no exogenous contrast agent, making it a more appropriate tool to monitor longitudinal perfusion changes in MS, providing a new window to study lesion development. Key Points • Perfusion can be quantified within cortical lesions in multiple sclerosis using an optimised high spatial resolution arterial spin Labelling MRI acquisition at ultra-high-field. • The majority of cortical lesions assessed using arterial spin labelling are hypo-perfused compared to normal appearing grey matter, in agreement with dynamic susceptibility contrast MRI literature. • Arterial spin labelling MRI, which does not involve the injection of a contrast agent, is a safe and appropriate technique for repeat scanning of an individual patient.
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Affiliation(s)
- Richard J Dury
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Yasser Falah
- Clinical Neurology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Penny A Gowland
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Nikos Evangelou
- Clinical Neurology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Molly G Bright
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK. .,Clinical Neurology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK. .,Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, 645 N. Michigan Avenue, Suite 1100, Chicago, IL, 60611, USA. .,Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA.
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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Haddock BT, Francis ST, Larsson HB, Andersen UB. Assessment of Perfusion and Oxygenation of the Human Renal Cortex and Medulla by Quantitative MRI during Handgrip Exercise. J Am Soc Nephrol 2018; 29:2510-2517. [PMID: 30206141 PMCID: PMC6171273 DOI: 10.1681/asn.2018030272] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/08/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Renal flow abnormalities are believed to play a central role in the pathogenesis of nephropathy and in primary and secondary hypertension, but are difficult to measure in humans. Handgrip exercise is known to reduce renal arterial flow (RAF) by means of increased renal sympathetic nerve activity. METHODS To monitor medullary and cortical oxygenation under handgrip exercise-reduced perfusion, we used contrast- and radiation-free magnetic resonance imaging (MRI) to measure regional changes in renal perfusion and blood oxygenation in ten healthy normotensive individuals during handgrip exercise. We used phase-contrast MRI to measure RAF, arterial spin labeling to measure perfusion, and both changes in transverse relaxation time (T2*) and dynamic blood oxygenation level-dependent imaging to measure blood oxygenation. RESULTS Handgrip exercise induced a significant decrease in RAF. In the renal medulla, this was accompanied by an increase of oxygenation (reflected by an increase in T2*) despite a significant drop in medullary perfusion; the renal cortex showed a significant decrease in both perfusion and oxygenation. We also found a significant correlation (R2=0.8) between resting systolic BP and the decrease in RAF during handgrip exercise. CONCLUSIONS Renal MRI measurements in response to handgrip exercise were consistent with a sympathetically mediated decrease in RAF. In the renal medulla, oxygenation increased despite a reduction in perfusion, which we interpreted as the result of decreased GFR and a subsequently reduced reabsorptive workload. Our results further indicate that the renal flow response's sensitivity to sympathetic activation is correlated with resting BP, even within a normotensive range.
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Affiliation(s)
- Bryan Thomas Haddock
- Department of Clinical Physiology, Nuclear Medicine and Positron Emission Tomography, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; and
| | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Henrik B.W. Larsson
- Department of Clinical Physiology, Nuclear Medicine and Positron Emission Tomography, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; and
| | - Ulrik B. Andersen
- Department of Clinical Physiology, Nuclear Medicine and Positron Emission Tomography, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; and
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Cox EF, Palaniyappan N, Aithal GP, Guha IN, Francis ST. MRI assessment of altered dynamic changes in liver haemodynamics following a meal challenge in compensated cirrhosis. Eur Radiol Exp 2018. [PMCID: PMC6156698 DOI: 10.1186/s41747-018-0056-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Odudu A, Nery F, Harteveld AA, Evans RG, Pendse D, Buchanan CE, Francis ST, Fernández-Seara MA. Arterial spin labelling MRI to measure renal perfusion: a systematic review and statement paper. Nephrol Dial Transplant 2018; 33:ii15-ii21. [PMID: 30137581 PMCID: PMC6106644 DOI: 10.1093/ndt/gfy180] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/15/2018] [Indexed: 01/03/2023] Open
Abstract
Renal perfusion provides the driving pressure for glomerular filtration and delivers the oxygen and nutrients to fuel solute reabsorption. Renal ischaemia is a major mechanism in acute kidney injury and may promote the progression of chronic kidney disease. Thus, quantifying renal tissue perfusion is critically important for both clinicians and physiologists. Current reference techniques for assessing renal tissue perfusion have significant limitations. Arterial spin labelling (ASL) is a magnetic resonance imaging (MRI) technique that uses magnetic labelling of water in arterial blood as an endogenous tracer to generate maps of absolute regional perfusion without requiring exogenous contrast. The technique holds enormous potential for clinical use but remains restricted to research settings. This statement paper from the PARENCHIMA network briefly outlines the ASL technique and reviews renal perfusion data in 53 studies published in English through January 2018. Renal perfusion by ASL has been validated against reference methods and has good reproducibility. Renal perfusion by ASL reduces with age and excretory function. Technical advancements mean that a renal ASL study can acquire a whole kidney perfusion measurement in less than 5-10 min. The short acquisition time permits combination with other MRI techniques that might inform drug mechanisms and renal physiology. The flexibility of renal ASL has yielded several variants of the technique, but there are limited data comparing these approaches. We make recommendations for acquiring and reporting renal ASL data and outline the knowledge gaps that future research should address.
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Affiliation(s)
- Aghogho Odudu
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Fabio Nery
- Developmental Imaging & Biophysics Section, University College London, Great Ormond Street Institute of Child Health, London, UK
| | - Anita A Harteveld
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Roger G Evans
- Department of Physiology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Douglas Pendse
- Centre for Medical Imaging, University College London, London, UK
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Pitiot A, Smith JK, Humes DJ, Garratt J, Francis ST, Gowland PA, Spiller RC, Marciani L. Cortical differences in diverticular disease and correlation with symptom reports. Neurogastroenterol Motil 2018; 30:e13303. [PMID: 29392838 DOI: 10.1111/nmo.13303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 01/07/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Recent studies have shown that the brain of patients with gastrointestinal disease differ both structurally and functionally from that of controls. Highly somatizing diverticular disease (HSDD) patients were also shown to differ from low somatizing (LSDD) patients functionally. This study aimed to investigate how they differed structurally. METHODS Four diseases subgroups were studied in a cross-sectional design: 20 patients with asymptomatic diverticular disease (ADD), 18 LSDD, 16 HSDD, and 18 with irritable bowel syndrome. We divided DD patients into LSDD and HSDD using a cutoff of 6 on the Patient Health Questionnaire 12 Somatic Symptom (PHQ12-SS) scale. All patients underwent a 1-mm isotropic structural brain MRI scan and were assessed for somatization, hospital anxiety, depression, and pain catastrophizing. Whole brain volumetry, cortical thickness analysis and voxel-based morphometry were carried out using Freesurfer and SPM. KEY RESULTS We observed decreases in gray matter density in the left and right dorsolateral prefrontal cortex (dlPFC), and in the mid-cingulate and motor cortex, and increases in the left (19, 20) and right (19, 38) Brodmann Areas. The average cortical thickness differed overall across groups (P = .002) and regionally: HSDD > ADD in the posterior cingulate cortex (P = .03), HSDD > LSDD in the dlPFC (P = .03) and in the ventrolateral PFC (P < .001). The thickness of the anterior cingulate cortex and of the mid-prefrontal cortex were also found to correlate with Pain Catastrophizing (Spearman's ρ = 0.24, P = .043 uncorrected and Spearman's ρ = 0.25, P = .03 uncorrected). CONCLUSION & INFERENCES This is the first study of structural gray matter abnormalities in diverticular disease patients. The data show brain differences in the pain network.
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Affiliation(s)
- A Pitiot
- Laboratory of Image & Data Analysis, Ilixa Ltd., Nottingham, UK
| | - J K Smith
- Nottingham Digestive Diseases Centre, NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
| | - D J Humes
- Nottingham Digestive Diseases Centre, NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
| | - J Garratt
- Nottingham Digestive Diseases Centre, NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
| | - S T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - P A Gowland
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - R C Spiller
- Nottingham Digestive Diseases Centre, NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
| | - L Marciani
- Nottingham Digestive Diseases Centre, NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
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Barratt EL, Francis ST, Morris PG, Brookes MJ. Mapping the topological organisation of beta oscillations in motor cortex using MEG. Neuroimage 2018; 181:831-844. [PMID: 29960087 PMCID: PMC6150950 DOI: 10.1016/j.neuroimage.2018.06.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/05/2018] [Accepted: 06/12/2018] [Indexed: 12/19/2022] Open
Abstract
The spatial topology of the human motor cortex has been well studied, particularly using functional Magnetic Resonance Imaging (fMRI) which allows spatial separation of haemodynamic responses arising from stimulation of different body parts, individual digits and even spatially separate areas of the same digit. However, the spatial organisation of electrophysiological responses, particularly neural oscillations (rhythmic changes in electrical potential across cellular assemblies) has been less well studied. Mapping the spatial signature of neural oscillations is possible using magnetoencephalography (MEG), however spatial differentiation of responses induced by movement of separate digits is a challenge, because the brain regions involved are separated by only a few millimetres. In this paper we first show, in simulation, how to optimise experimental design and beamformer spatial filtering techniques to increase the spatial specificity of MEG derived functional images. Combining this result with experimental data, we then capture the organisation of the post-movement beta band (13–30 Hz) oscillatory response to movement of digits 2 and 5 of the dominant hand, in individual subjects. By comparing these MEG results to ultra-high field (7T) fMRI, we also show significant spatial agreement between beta modulation and the blood oxygenation level dependent (BOLD) response. Our results show that, when using an optimised inverse solution and controlling subject movement (using custom fitted foam padding) the spatial resolution of MEG can be of order 3–5 mm. The method described offers exciting potential to understand better the cortical organisation of oscillations, and to probe such organisation in patient populations where those oscillations are known to be abnormal. Aim is to map the topological organisation of neural oscillations in motor cortex. MEG spatial resolution optimised by temporal separation of sources. Subject motion controlled using foam headcasts. Cortical representation of Digit 2 and Digit 5 separated spatially. Post movement beta rebound maps motortopically in agreement with BOLD responses.
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Affiliation(s)
- Eleanor L Barratt
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Peter G Morris
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
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Scott RA, Aithal GP, Francis ST, Irving WL. Pretreatment Lesions on Magnetic Resonance Imaging in Patients With Hepatitis C Virus Infection Diagnosed With Hepatocellular Carcinoma After Initiating Direct-Acting Antiviral Therapy. Gastroenterology 2018; 154:1848-1850. [PMID: 29621514 DOI: 10.1053/j.gastro.2017.12.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 12/11/2017] [Indexed: 12/02/2022]
Affiliation(s)
- Robert A Scott
- National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham and Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Guruprasad P Aithal
- National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham and Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre, Nottingham University Hospitals, NHS Trust and the University of Nottingham and Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - William L Irving
- National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham and Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, UK
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Dewey RS, Hall DA, Guest H, Prendergast G, Plack CJ, Francis ST. The Physiological Bases of Hidden Noise-Induced Hearing Loss: Protocol for a Functional Neuroimaging Study. JMIR Res Protoc 2018. [PMID: 29523503 PMCID: PMC5866298 DOI: 10.2196/resprot.9095] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Rodent studies indicate that noise exposure can cause permanent damage to synapses between inner hair cells and high-threshold auditory nerve fibers, without permanently altering threshold sensitivity. These demonstrations of what is commonly known as hidden hearing loss have been confirmed in several rodent species, but the implications for human hearing are unclear. Objective Our Medical Research Council–funded program aims to address this unanswered question, by investigating functional consequences of the damage to the human peripheral and central auditory nervous system that results from cumulative lifetime noise exposure. Behavioral and neuroimaging techniques are being used in a series of parallel studies aimed at detecting hidden hearing loss in humans. The planned neuroimaging study aims to (1) identify central auditory biomarkers associated with hidden hearing loss; (2) investigate whether there are any additive contributions from tinnitus or diminished sound tolerance, which are often comorbid with hearing problems; and (3) explore the relation between subcortical functional magnetic resonance imaging (fMRI) measures and the auditory brainstem response (ABR). Methods Individuals aged 25 to 40 years with pure tone hearing thresholds ≤20 dB hearing level over the range 500 Hz to 8 kHz and no contraindications for MRI or signs of ear disease will be recruited into the study. Lifetime noise exposure will be estimated using an in-depth structured interview. Auditory responses throughout the central auditory system will be recorded using ABR and fMRI. Analyses will focus predominantly on correlations between lifetime noise exposure and auditory response characteristics. Results This paper reports the study protocol. The funding was awarded in July 2013. Enrollment for the study described in this protocol commenced in February 2017 and was completed in December 2017. Results are expected in 2018. Conclusions This challenging and comprehensive study will have the potential to impact diagnostic procedures for hidden hearing loss, enabling early identification of noise-induced auditory damage via the detection of changes in central auditory processing. Consequently, this will generate the opportunity to give personalized advice regarding provision of ear defense and monitoring of further damage, thus reducing the incidence of noise-induced hearing loss.
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Affiliation(s)
- Rebecca Susan Dewey
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.,National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,Otology and Hearing Group, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Deborah A Hall
- National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,Otology and Hearing Group, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Hannah Guest
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom.,National Institute for Health Research Manchester Biomedical Research Centre, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Garreth Prendergast
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom.,National Institute for Health Research Manchester Biomedical Research Centre, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Christopher J Plack
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom.,National Institute for Health Research Manchester Biomedical Research Centre, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom.,Department of Psychology, Lancaster University, Lancaster, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
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Uji M, Wilson R, Francis ST, Mullinger KJ, Mayhew SD. Exploring the advantages of multiband fMRI with simultaneous EEG to investigate coupling between gamma frequency neural activity and the BOLD response in humans. Hum Brain Mapp 2018; 39:1673-1687. [PMID: 29331056 DOI: 10.1002/hbm.23943] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/17/2017] [Accepted: 12/21/2017] [Indexed: 01/18/2023] Open
Abstract
We established an optimal combination of EEG recording during sparse multiband (MB) fMRI that preserves high-resolution, whole-brain fMRI coverage while enabling broad-band EEG recordings which are uncorrupted by MRI gradient artefacts (GAs). We first determined the safety of simultaneous EEG recording during MB fMRI. Application of MB factor = 4 produced <1°C peak heating of electrode/hardware during 20 min of GE-EPI data acquisition. However, higher SAR sequences require specific safety testing, with greater heating observed using PCASL with MB factor = 4. Heating was greatest in the electrocardiogram channel, likely due to it possessing longest lead length. We investigated the effect of MB factor on the temporal signal-to-noise ratio for a range of GE-EPI sequences (varying MB factor and temporal interval between slice acquisitions). We found that, for our experimental purpose, the optimal acquisition was achieved with MB factor = 3, 3mm isotropic voxels, and 33 slices providing whole head coverage. This sequence afforded a 2.25 s duration quiet period (without GAs) in every 3 s TR. Using this sequence, we demonstrated the ability to record gamma frequency (55-80 Hz) EEG oscillations, in response to right index finger abduction, that are usually obscured by GAs during continuous fMRI data acquisition. In this novel application of EEG-MB fMRI to a motor task, we observed a positive correlation between gamma and BOLD responses in bilateral motor regions. These findings support and extend previous work regarding coupling between neural and hemodynamic measures of brain activity in humans and showcase the utility of EEG-MB fMRI for future investigations.
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Affiliation(s)
- Makoto Uji
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Ross Wilson
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom.,Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Stephen D Mayhew
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
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Cox EF, Buchanan CE, Bradley CR, Prestwich B, Mahmoud H, Taal M, Selby NM, Francis ST. Multiparametric Renal Magnetic Resonance Imaging: Validation, Interventions, and Alterations in Chronic Kidney Disease. Front Physiol 2017; 8:696. [PMID: 28959212 PMCID: PMC5603702 DOI: 10.3389/fphys.2017.00696] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 08/30/2017] [Indexed: 12/15/2022] Open
Abstract
Background: This paper outlines a multiparametric renal MRI acquisition and analysis protocol to allow non-invasive assessment of hemodynamics (renal artery blood flow and perfusion), oxygenation (BOLD T2*), and microstructure (diffusion, T1 mapping). Methods: We use our multiparametric renal MRI protocol to provide (1) a comprehensive set of MRI parameters [renal artery and vein blood flow, perfusion, T1, T2*, diffusion (ADC, D, D*, fp), and total kidney volume] in a large cohort of healthy participants (127 participants with mean age of 41 ± 19 years) and show the MR field strength (1.5 T vs. 3 T) dependence of T1 and T2* relaxation times; (2) the repeatability of multiparametric MRI measures in 11 healthy participants; (3) changes in MRI measures in response to hypercapnic and hyperoxic modulations in six healthy participants; and (4) pilot data showing the application of the multiparametric protocol in 11 patients with Chronic Kidney Disease (CKD). Results: Baseline measures were in-line with literature values, and as expected, T1-values were longer at 3 T compared with 1.5 T, with increased T1 corticomedullary differentiation at 3 T. Conversely, T2* was longer at 1.5 T. Inter-scan coefficients of variation (CoVs) of T1 mapping and ADC were very good at <2.9%. Intra class correlations (ICCs) were high for cortex perfusion (0.801), cortex and medulla T1 (0.848 and 0.997 using SE-EPI), and renal artery flow (0.844). In response to hypercapnia, a decrease in cortex T2* was observed, whilst no significant effect of hyperoxia on T2* was found. In CKD patients, renal artery and vein blood flow, and renal perfusion was lower than for healthy participants. Renal cortex and medulla T1 was significantly higher in CKD patients compared to healthy participants, with corticomedullary T1 differentiation reduced in CKD patients compared to healthy participants. No significant difference was found in renal T2*. Conclusions: Multiparametric MRI is a powerful technique for the assessment of changes in structure, hemodynamics, and oxygenation in a single scan session. This protocol provides the potential to assess the pathophysiological mechanisms in various etiologies of renal disease, and to assess the efficacy of drug treatments.
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Affiliation(s)
- Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Benjamin Prestwich
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Huda Mahmoud
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Maarten Taal
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
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Tan FM, Caballero-Gaudes C, Mullinger KJ, Cho SY, Zhang Y, Dryden IL, Francis ST, Gowland PA. Decoding fMRI events in sensorimotor motor network using sparse paradigm free mapping and activation likelihood estimates. Hum Brain Mapp 2017; 38:5778-5794. [PMID: 28815863 DOI: 10.1002/hbm.23767] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 07/30/2017] [Accepted: 08/02/2017] [Indexed: 11/12/2022] Open
Abstract
Most functional MRI (fMRI) studies map task-driven brain activity using a block or event-related paradigm. Sparse paradigm free mapping (SPFM) can detect the onset and spatial distribution of BOLD events in the brain without prior timing information, but relating the detected events to brain function remains a challenge. In this study, we developed a decoding method for SPFM using a coordinate-based meta-analysis method of activation likelihood estimation (ALE). We defined meta-maps of statistically significant ALE values that correspond to types of events and calculated a summation overlap between the normalized meta-maps and SPFM maps. As a proof of concept, this framework was applied to relate SPFM-detected events in the sensorimotor network (SMN) to six motor functions (left/right fingers, left/right toes, swallowing, and eye blinks). We validated the framework using simultaneous electromyography (EMG)-fMRI experiments and motor tasks with short and long duration, and random interstimulus interval. The decoding scores were considerably lower for eye movements relative to other movement types tested. The average successful rate for short and long motor events were 77 ± 13% and 74 ± 16%, respectively, excluding eye movements. We found good agreement between the decoding results and EMG for most events and subjects, with a range in sensitivity between 55% and 100%, excluding eye movements. The proposed method was then used to classify the movement types of spontaneous single-trial events in the SMN during resting state, which produced an average successful rate of 22 ± 12%. Finally, this article discusses methodological implications and improvements to increase the decoding performance. Hum Brain Mapp 38:5778-5794, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Francisca M Tan
- School of Physics and Astronomy and Sir Peter Mansfield Imaging Centre, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.,Department of Electrical and Electronic Engineering, University of Nottingham Ningbo China, Ningbo, 315100, People's Republic of China
| | | | - Karen J Mullinger
- School of Physics and Astronomy and Sir Peter Mansfield Imaging Centre, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.,Birmingham University Imaging Centre, School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Siu-Yeung Cho
- Department of Electrical and Electronic Engineering, University of Nottingham Ningbo China, Ningbo, 315100, People's Republic of China
| | - Yaping Zhang
- Department of Electrical and Electronic Engineering, University of Nottingham Ningbo China, Ningbo, 315100, People's Republic of China
| | - Ian L Dryden
- School of Mathematical Sciences, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Susan T Francis
- School of Physics and Astronomy and Sir Peter Mansfield Imaging Centre, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Penny A Gowland
- School of Physics and Astronomy and Sir Peter Mansfield Imaging Centre, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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Mullinger KJ, Cherukara MT, Buxton RB, Francis ST, Mayhew SD. Post-stimulus fMRI and EEG responses: Evidence for a neuronal origin hypothesised to be inhibitory. Neuroimage 2017; 157:388-399. [PMID: 28610902 DOI: 10.1016/j.neuroimage.2017.06.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 06/05/2017] [Accepted: 06/09/2017] [Indexed: 12/26/2022] Open
Abstract
Post-stimulus undershoots, negative responses following cessation of stimulation, are widely observed in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) data. However, the debate surrounding whether the origin of this response phase is neuronal or vascular, and whether it provides functionally relevant information, that is additional to what is contained in the primary response, means that undershoots are widely overlooked. We simultaneously recorded electroencephalography (EEG), BOLD and cerebral blood-flow (CBF) [obtained from arterial spin labelled (ASL) fMRI] fMRI responses to hemifield checkerboard stimulation to test the potential neural origin of the fMRI post-stimulus undershoot. The post-stimulus BOLD and CBF signal amplitudes in both contralateral and ipsilateral visual cortex depended on the post-stimulus power of the occipital 8-13Hz (alpha) EEG neuronal activity, such that trials with highest EEG power showed largest fMRI undershoots in contralateral visual cortex. This correlation in post-stimulus EEG-fMRI responses was not predicted by the primary response amplitude. In the contralateral visual cortex we observed a decrease in both cerebral rate of oxygen metabolism (CMRO2) and CBF during the post-stimulus phase. In addition, the coupling ratio (n) between CMRO2 and CBF was significantly lower during the positive contralateral primary response phase compared with the post-stimulus phase and we propose that this reflects an altered balance of excitatory and inhibitory neuronal activity. Together our data provide strong evidence that the post-stimulus phase of the BOLD response has a neural origin which reflects, at least partially, an uncoupling of the neuronal responses driving the primary and post-stimulus responses, explaining the uncoupling of the signals measured in the two response phases. We suggest our results are consistent with inhibitory processes driving the post-stimulus EEG and fMRI responses. We therefore propose that new methods are required to model the post-stimulus and primary responses independently, enabling separate investigation of response phases in cognitive function and neurological disease.
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Affiliation(s)
- K J Mullinger
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Birmingham University Imaging Centre, School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
| | - M T Cherukara
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - R B Buxton
- Department of Radiology, Center for Functional MRI, University of California, San Diego, La Jolla, CA, USA
| | - S T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - S D Mayhew
- Birmingham University Imaging Centre, School of Psychology, University of Birmingham, Birmingham B15 2TT, UK
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Chen C, Stephenson MC, Peters A, Morris PG, Francis ST, Gowland PA. 31 P magnetization transfer magnetic resonance spectroscopy: Assessing the activation induced change in cerebral ATP metabolic rates at 3 T. Magn Reson Med 2017; 79:22-30. [PMID: 28303591 PMCID: PMC5706641 DOI: 10.1002/mrm.26663] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 02/05/2017] [Accepted: 02/09/2017] [Indexed: 12/19/2022]
Abstract
Purpose In vivo 31P magnetic resonance spectroscopy (MRS) magnetization transfer (MT) provides a direct measure of neuronal activity at the metabolic level. This work aims to use functional 31P MRS‐MT to investigate the change in cerebral adenosine triphosphate (ATP) metabolic rates in healthy adults upon repeated visual stimuli. Methods A magnetization saturation transfer sequence with narrowband selective saturation of γ‐ATP was developed for 31P MT experiments at 3 T. Results Using progressive saturation of γ‐ATP, the intrinsic T1 relaxation times of phosphocreatine (PCr) and inorganic phosphate (Pi) at 3 T were measured to be 5.1 ± 0.8 s and 3.0 ± 1.4 s, respectively. Using steady‐state saturation of γ‐ATP, a significant 24% ± 14% and 11% ± 7% increase in the forward creatine kinase (CK) pseudo‐first‐order reaction rate constant, k1, was observed upon visual stimulation in the first and second cycles, respectively, of a paradigm consisting of 10‐minute rest followed by 10‐minute stimulation, with the measured baseline k1 being 0.35 ± 0.04 s−1. No significant changes in forward ATP synthase reaction rate, PCr/γ‐ATP, Pi/γ‐ATP, and nicotinamide adenine dinucleotide/γ‐ATP ratios, or intracellular pH were detected upon stimulation. Conclusion This work demonstrates the potential of studying cerebral bioenergetics using functional 31P MRS‐MT to determine the change in the forward CK reaction rate at 3 T. Magn Reson Med 79:22–30, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Chen Chen
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Mary C Stephenson
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Andrew Peters
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Peter G Morris
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Penny A Gowland
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
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