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Vucevic D, Malis V, Bae WC, Ota H, Oshio K, McDonald MA, Miyazaki M. Visualization of Cerebrospinal Fluid Outflow and Egress along the Nerve Roots of the Lumbar Spine. Bioengineering (Basel) 2024; 11:708. [PMID: 39061790 PMCID: PMC11273714 DOI: 10.3390/bioengineering11070708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
Intrinsic cerebrospinal fluid (CSF) dynamics in the brain have been extensively studied, particularly the egress sites of tagged intrinsic CSF in the meninges. Although spinal CSF recirculates within the central nervous system (CNS), we hypothesized that CSF outflows from the lumbar spinal canal. We aimed to visualize and semi-quantify the outflow using non-contrast MRI techniques. We utilized a 3 Tesla clinical MRI with a 16-channel spine coil, employing time-spatial labeling inversion (Time-SLIP) with tag-on and tag-off acquisitions, T2-weighted coronal 2D fluid-attenuated inversion recovery (FLAIR) and T2-weighted coronal 3D centric ky-kz single-shot FSE (cSSFSE). Images were acquired using time-spatial labeling inversion pulse (Time-SLIP) with tag-on and tag-off acquisitions with varying TI periods. Ten healthy volunteers with no known spinal diseases participated. Variations in tagged CSF outflow were observed across different thoracolumbar nerve root segments in all participants. We quantified CSF outflow at all lumbar levels and the psoas region. There was no significant difference among the ROIs for signal intensity. The tagged CSF outflow from the spinal canal is small but demonstrates egress to surrounding tissues. This finding may pave the way for exploring intrathecal drug delivery, understanding of CSF-related pathologies and its potential as a biomarker for peripheral neuropathy and radiculopathy.
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Affiliation(s)
- Diana Vucevic
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA; (D.V.); (V.M.); (W.C.B.); (M.A.M.)
| | - Vadim Malis
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA; (D.V.); (V.M.); (W.C.B.); (M.A.M.)
| | - Won C. Bae
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA; (D.V.); (V.M.); (W.C.B.); (M.A.M.)
- Department of Radiology, VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Hideki Ota
- Department of Radiology, Tohoku University, Sendai 980-8576, Miyagi, Japan;
| | - Koichi Oshio
- Department of Radiology, Juntendo University, Tokyo 113-8421, Japan;
| | - Marin A. McDonald
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA; (D.V.); (V.M.); (W.C.B.); (M.A.M.)
| | - Mitsue Miyazaki
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA; (D.V.); (V.M.); (W.C.B.); (M.A.M.)
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Padrela B, Mahroo A, Tee M, Sneve MH, Moyaert P, Geier O, Kuijer JPA, Beun S, Nordhøy W, Zhu YD, Buck MA, Hoinkiss DC, Konstandin S, Huber J, Wiersinga J, Rikken R, de Leeuw D, Grydeland H, Tippett L, Cawston EE, Ozturk-Isik E, Linn J, Brandt M, Tijms BM, van de Giessen EM, Muller M, Fjell A, Walhovd K, Bjørnerud A, Pålhaugen L, Selnes P, Clement P, Achten E, Anazodo U, Barkhof F, Hilal S, Fladby T, Eickel K, Morgan C, Thomas DL, Petr J, Günther M, Mutsaerts HJMM. Developing blood-brain barrier arterial spin labelling as a non-invasive early biomarker of Alzheimer's disease (DEBBIE-AD): a prospective observational multicohort study protocol. BMJ Open 2024; 14:e081635. [PMID: 38458785 DOI: 10.1136/bmjopen-2023-081635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/10/2024] Open
Abstract
INTRODUCTION Loss of blood-brain barrier (BBB) integrity is hypothesised to be one of the earliest microvascular signs of Alzheimer's disease (AD). Existing BBB integrity imaging methods involve contrast agents or ionising radiation, and pose limitations in terms of cost and logistics. Arterial spin labelling (ASL) perfusion MRI has been recently adapted to map the BBB permeability non-invasively. The DEveloping BBB-ASL as a non-Invasive Early biomarker (DEBBIE) consortium aims to develop this modified ASL-MRI technique for patient-specific and robust BBB permeability assessments. This article outlines the study design of the DEBBIE cohorts focused on investigating the potential of BBB-ASL as an early biomarker for AD (DEBBIE-AD). METHODS AND ANALYSIS DEBBIE-AD consists of a multicohort study enrolling participants with subjective cognitive decline, mild cognitive impairment and AD, as well as age-matched healthy controls, from 13 cohorts. The precision and accuracy of BBB-ASL will be evaluated in healthy participants. The clinical value of BBB-ASL will be evaluated by comparing results with both established and novel AD biomarkers. The DEBBIE-AD study aims to provide evidence of the ability of BBB-ASL to measure BBB permeability and demonstrate its utility in AD and AD-related pathologies. ETHICS AND DISSEMINATION Ethics approval was obtained for 10 cohorts, and is pending for 3 cohorts. The results of the main trial and each of the secondary endpoints will be submitted for publication in a peer-reviewed journal.
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Affiliation(s)
- Beatriz Padrela
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | - Amnah Mahroo
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Mervin Tee
- National University Health System, Singapore
| | - Markus H Sneve
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
| | - Paulien Moyaert
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Diagnostic Sciences, University Hospital Ghent, Gent, Belgium
| | - Oliver Geier
- Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
| | - Joost P A Kuijer
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | - Soetkin Beun
- Department of Diagnostic Sciences, University Hospital Ghent, Gent, Belgium
| | - Wibeke Nordhøy
- Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
| | - Yufei David Zhu
- Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Mareike A Buck
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
- University of Bremen, Bremen, Germany
| | | | - Simon Konstandin
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Jörn Huber
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Julia Wiersinga
- Department of Internal Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | - Roos Rikken
- Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | | | - Håkon Grydeland
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
| | - Lynette Tippett
- The University of Auckland School of Psychology, Auckland, New Zealand
| | - Erin E Cawston
- The University of Auckland Department of Pharmacology and Clinical Pharmacology, Auckland, New Zealand
| | - Esin Ozturk-Isik
- Bogazici University Institute of Biomedical Engineering, Istanbul, Turkey
| | - Jennifer Linn
- Department of Neurology, Faculty of Medicine, Babylon, Iraq
- Department of Neurology, Technische Universität Dresden, Dresden, Germany
| | - Moritz Brandt
- Department of Neurology, Faculty of Medicine, Babylon, Iraq
- Department of Neurology, Technische Universität Dresden, Dresden, Germany
| | - Betty M Tijms
- Neurology, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | | | - Majon Muller
- Department of Internal Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
| | - Anders Fjell
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
- Oslo University Hospital, Oslo, Norway
| | - Kristine Walhovd
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
- Oslo University Hospital, Oslo, Norway
| | - Atle Bjørnerud
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
- Oslo University Hospital, Oslo, Norway
| | - Lene Pålhaugen
- Department of Neurology, Akershus University Hospital, Lorenskog, Norway
- University of Oslo, Oslo, Norway
| | - Per Selnes
- Department of Neurology, Akershus University Hospital, Lorenskog, Norway
| | - Patricia Clement
- Department of Diagnostic Sciences, University Hospital Ghent, Gent, Belgium
| | - Eric Achten
- Department of Diagnostic Sciences, University Hospital Ghent, Gent, Belgium
| | - Udunna Anazodo
- Lawson Health Research Institute, London, Ontario, Canada
| | - Frederik Barkhof
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
- University College London, London, UK
| | - Saima Hilal
- National University Health System, Singapore
- Department of Pharmacology, National University of Singapore, Singapore
| | - Tormod Fladby
- Department of Neurology, Akershus University Hospital, Lorenskog, Norway
- University of Oslo, Oslo, Norway
| | - Klaus Eickel
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
- University of Applied Sciences Bremerhaven, Bremerhaven, Germany
| | - Catherine Morgan
- The University of Auckland School of Psychology, Auckland, New Zealand
| | - David L Thomas
- Department of Brain Repair and Rehabilitation, University College London, London, UK
| | - Jan Petr
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Matthias Günther
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
- University of Bremen, Bremen, Germany
| | - Henk J M M Mutsaerts
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Locatie VUmc, Amsterdam, Netherlands
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Malis V, Bae WC, Yamamoto A, McEvoy LK, McDonald MA, Miyazaki M. Age-related Decline of Intrinsic Cerebrospinal Fluid Outflow in Healthy Humans Detected with Non-contrast Spin-labeling MR Imaging. Magn Reson Med Sci 2024; 23:66-79. [PMID: 36529500 PMCID: PMC10838716 DOI: 10.2463/mrms.mp.2022-0117] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 10/24/2022] [Indexed: 01/05/2024] Open
Abstract
PURPOSE Clearance of cerebrospinal fluid (CSF) is important for the removal of toxins from the brain, with implications for neurodegenerative diseases. Imaging evaluation of CSF outflow in humans has been limited, relying on venous or invasive intrathecal injections of contrast agents. The objective of this study was to introduce a novel spin-labeling MRI technique to detect and quantify the movement of endogenously tagged CSF, and then apply it to evaluate CSF outflow in normal humans of varying ages. METHODS This study was performed on a clinical 3-Tesla MRI scanner in 16 healthy subjects with an age range of 19-71 years with informed consent. Our spin-labeling MRI technique applies a tag pulse on the brain hemisphere, and images the outflow of the tagged CSF into the superior sagittal sinus (SSS). We obtained 3D images in real time, which was analyzed to determine tagged-signal changes in different regions of the meninges involved in CSF outflow. Additionally, the signal changes over time were fit to a signal curve to determine quantitative flow metrics. These were correlated against subject age to determine aging effects. RESULTS We observed the signal of the tagged CSF moving from the dura mater and parasagittal dura, and finally draining into the SSS. In addition, we observed a possibility of another pathway which is seen in some young subjects. Furthermore, quantitative CSF outflow metrics were shown to decrease significantly with age. CONCLUSION We demonstrate a novel non-invasive MRI technique identifying two intrinsic CSF clearance pathways, and observe an age-related decline of CSF flow metrics in healthy subjects. Our work provides a new opportunity to better understand the relationships of these CSF clearance pathways during the aging process, which may ultimately provide insight into the age-related prevalence of neurodegenerative diseases.
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Affiliation(s)
- Vadim Malis
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Won C. Bae
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
- Department of Radiology, Veterans Affairs Healthcare System, La Jolla, CA, USA
| | - Asako Yamamoto
- Department of Radiology, Teikyo University, Tokyo, Japan
| | - Linda K. McEvoy
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California San Diego, La Jolla, CA, USA
| | - Marin A. McDonald
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Mitsue Miyazaki
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
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Powell E, Ohene Y, Battiston M, Dickie BR, Parkes LM, Parker GJM. Blood-brain barrier water exchange measurements using FEXI: Impact of modeling paradigm and relaxation time effects. Magn Reson Med 2023; 90:34-50. [PMID: 36892973 PMCID: PMC10962589 DOI: 10.1002/mrm.29616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/25/2023] [Accepted: 01/25/2023] [Indexed: 03/10/2023]
Abstract
PURPOSE To evaluate potential modeling paradigms and the impact of relaxation time effects on human blood-brain barrier (BBB) water exchange measurements using FEXI (BBB-FEXI), and to quantify the accuracy, precision, and repeatability of BBB-FEXI exchange rate estimates at 3 T $$ \mathrm{T} $$ . METHODS Three modeling paradigms were evaluated: (i) the apparent exchange rate (AXR) model; (ii) a two-compartment model (2 CM $$ 2\mathrm{CM} $$ ) explicitly representing intra- and extravascular signal components, and (iii) a two-compartment model additionally accounting for finite compartmentalT 1 $$ {\mathrm{T}}_1 $$ andT 2 $$ {\mathrm{T}}_2 $$ relaxation times (2 CM r $$ 2{\mathrm{CM}}_r $$ ). Each model had three free parameters. Simulations quantified biases introduced by the assumption of infinite relaxation times in the AXR and2 CM $$ 2\mathrm{CM} $$ models, as well as the accuracy and precision of all three models. The scan-rescan repeatability of all paradigms was quantified for the first time in vivo in 10 healthy volunteers (age range 23-52 years; five female). RESULTS The assumption of infinite relaxation times yielded exchange rate errors in simulations up to 42%/14% in the AXR/2 CM $$ 2\mathrm{CM} $$ models, respectively. Accuracy was highest in the compartmental models; precision was best in the AXR model. Scan-rescan repeatability in vivo was good for all models, with negligible bias and repeatability coefficients in grey matter ofRC AXR = 0 . 43 $$ {\mathrm{RC}}_{\mathrm{AXR}}=0.43 $$ s - 1 $$ {\mathrm{s}}^{-1} $$ ,RC 2 CM = 0 . 51 $$ {\mathrm{RC}}_{2\mathrm{CM}}=0.51 $$ s - 1 $$ {\mathrm{s}}^{-1} $$ , andRC 2 CM r = 0 . 61 $$ {\mathrm{RC}}_{2{\mathrm{CM}}_r}=0.61 $$ s - 1 $$ {\mathrm{s}}^{-1} $$ . CONCLUSION Compartmental modelling of BBB-FEXI signals can provide accurate and repeatable measurements of BBB water exchange; however, relaxation time and partial volume effects may cause model-dependent biases.
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Affiliation(s)
- Elizabeth Powell
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
| | - Yolanda Ohene
- Division of Psychology, Communication and Human Neuroscience, School of Health Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science CentreUniversity of ManchesterManchesterUK
| | - Marco Battiston
- Queen Square MS CentreUCL Institute of Neurology, University College LondonLondonUK
| | - Ben R. Dickie
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science CentreUniversity of ManchesterManchesterUK
- Division of Informatics, Imaging and Data SciencesSchool of Health Sciences, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUK
| | - Laura M. Parkes
- Division of Psychology, Communication and Human Neuroscience, School of Health Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science CentreUniversity of ManchesterManchesterUK
| | - Geoff J. M. Parker
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
- Queen Square MS CentreUCL Institute of Neurology, University College LondonLondonUK
- Bioxydyn LimitedManchesterUK
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Petitclerc L, Hirschler L, Örzsik B, Asllani I, van Osch MJP. Arterial spin labeling signal in the CSF: Implications for partial volume correction and blood-CSF barrier characterization. NMR IN BIOMEDICINE 2023; 36:e4852. [PMID: 36269104 PMCID: PMC10078195 DOI: 10.1002/nbm.4852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/21/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
For better quantification of perfusion with arterial spin labeling (ASL), partial volume correction (PVC) is used to disentangle the signals from gray matter (GM) and white matter within any voxel. Based on physiological considerations, PVC algorithms typically assume zero signal in the cerebrospinal fluid (CSF). Recent measurements, however, have shown that CSF-ASL signal can exceed 10% of GM signal, even when using recommended ASL labeling parameters. CSF signal is expected to particularly affect PVC results in the choroid plexus. This study aims to measure the impact of CSF signal on PVC perfusion measurements, and to investigate the potential use of PVC to retrieve pure CSF-ASL signal for blood-CSF barrier characterization. In vivo imaging included six pCASL sequences with variable label duration and post-labeling delay (PLD), and an eight-echo 3D-GRASE readout. A dataset was simulated to estimate the effect of CSF-PVC with known ground-truth parameters. Differences between the results of CSF-PVC and non-CSF-PVC were estimated for regions of interest (ROIs) based on GM probability, and a separate ROI isolating the choroid plexus. In vivo, the suitability of PVC-CSF signal as an estimate of pure CSF was investigated by comparing its time course with the long-TE CSF signal. Results from both simulation and in vivo data indicated that including the CSF signal in PVC improves quantification of GM CBF by approximately 10%. In simulated data, this improvement was greater for multi-PLD (model fitting) quantification than for single PLD (~1-5% difference). In the choroid plexus, the difference between CSF-PVC and non-CSF-PVC was much larger, averaging around 30%. Long-TE (pure) CSF signal could not be estimated from PVC CSF signal as it followed a different time course, indicating the presence of residual macrovascular signal in the PVC. The inclusion of CSF adds value to PVC for more accurate measurements of GM perfusion, and especially for quantification of perfusion in the choroid plexus and study of the glymphatic system.
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Affiliation(s)
- Léonie Petitclerc
- C.J. Gorter MRI Center, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
- Leiden Institute for Brain and Cognition (LIBC)LeidenThe Netherlands
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Lydiane Hirschler
- C.J. Gorter MRI Center, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Balázs Örzsik
- Clinical Imaging Science Center, Department of NeuroscienceUniversity of SussexBrightonUK
| | - Iris Asllani
- Clinical Imaging Science Center, Department of NeuroscienceUniversity of SussexBrightonUK
- Department of Biomedical EngineeringRochester Institute of TechnologyRochesterNYUSA
| | - Matthias J. P. van Osch
- C.J. Gorter MRI Center, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
- Leiden Institute for Brain and Cognition (LIBC)LeidenThe Netherlands
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
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Jang H, Sedaghat S, Athertya JS, Moazamian D, Carl M, Ma Y, Lu X, Ji A, Chang EY, Du J. Feasibility of ultrashort echo time quantitative susceptibility mapping with a 3D cones trajectory in the human brain. Front Neurosci 2022; 16:1033801. [PMID: 36419458 PMCID: PMC9676465 DOI: 10.3389/fnins.2022.1033801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/21/2022] [Indexed: 11/09/2022] Open
Abstract
Purpose Quantitative susceptibility mapping (QSM) has surfaced as a promising non-invasive quantitative biomarker that provides information about tissue composition and microenvironment. Recently, ultrashort echo time quantitative susceptibility mapping (UTE-QSM) has been investigated to achieve QSM of short T2 tissues. As the feasibility of UTE-QSM has not been demonstrated in the brain, the goal of this study was to develop a UTE-QSM with an efficient 3D cones trajectory and validate it in the human brain. Materials and methods An ultrashort echo time (UTE) cones sequence was implemented in a 3T clinical MRI scanner. Six images were acquired within a single acquisition, including UTE and gradient recalled echo (GRE) images. To achieve QSM, a morphology-enabled dipole inversion (MEDI) algorithm was incorporated, which utilizes both magnitude and phase images. Three fresh cadaveric human brains were scanned using the 3D cones trajectory with eight stretching factors (SFs) ranging from 1.0 to 1.7. In addition, five healthy volunteers were recruited and underwent UTE-QSM to demonstrate the feasibility in vivo. The acquired data were processed with the MEDI-QSM pipeline. Results The susceptibility maps estimated by UTE-QSM showed reliable tissue contrast. In the ex vivo experiment, high correlations were found between the baseline (SF of 1.0) and SFs from 1.1 to 1.7 with Pearson's correlations of 0.9983, 0.9968, 0.9959, 0.9960, 0.9954, 0.9943, and 0.9879, respectively (all p-values < 0.05). In the in vivo experiment, the measured QSM values in cortical gray matter, juxtacortical white matter, corpus callosum, caudate, and putamen were 25.4 ± 4.0, -21.8 ± 3.2, -22.6 ± 10.0, 77.5 ± 18.8, and 53.8 ± 7.1 ppb, consistent with the values reported in the literature. Conclusion Ultrashort echo time quantitative susceptibility mapping enables direct estimation of the magnetic susceptibility in the brain with a dramatically reduced total scan time by use of a stretched 3D cones trajectory. This technique provides a new biomarker for susceptibility mapping in the in vivo brain.
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Affiliation(s)
- Hyungseok Jang
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Sam Sedaghat
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Jiyo S. Athertya
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Dina Moazamian
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | | | - Yajun Ma
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Xing Lu
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Alicia Ji
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Radiology Service, Veterans Affairs (VA) San Diego Healthcare System, San Diego, CA, United States
| | - Jiang Du
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
- Radiology Service, Veterans Affairs (VA) San Diego Healthcare System, San Diego, CA, United States
- Department of Bioengineering, University of California, San Diego, San Diego, CA, United States
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Chen JJ, Uthayakumar B, Hyder F. Mapping oxidative metabolism in the human brain with calibrated fMRI in health and disease. J Cereb Blood Flow Metab 2022; 42:1139-1162. [PMID: 35296177 PMCID: PMC9207484 DOI: 10.1177/0271678x221077338] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Conventional functional MRI (fMRI) with blood-oxygenation level dependent (BOLD) contrast is an important tool for mapping human brain activity non-invasively. Recent interest in quantitative fMRI has renewed the importance of oxidative neuroenergetics as reflected by cerebral metabolic rate of oxygen consumption (CMRO2) to support brain function. Dynamic CMRO2 mapping by calibrated fMRI require multi-modal measurements of BOLD signal along with cerebral blood flow (CBF) and/or volume (CBV). In human subjects this "calibration" is typically performed using a gas mixture containing small amounts of carbon dioxide and/or oxygen-enriched medical air, which are thought to produce changes in CBF (and CBV) and BOLD signal with minimal or no CMRO2 changes. However non-human studies have demonstrated that the "calibration" can also be achieved without gases, revealing good agreement between CMRO2 changes and underlying neuronal activity (e.g., multi-unit activity and local field potential). Given the simpler set-up of gas-free calibrated fMRI, there is evidence of recent clinical applications for this less intrusive direction. This up-to-date review emphasizes technological advances for such translational gas-free calibrated fMRI experiments, also covering historical progression of the calibrated fMRI field that is impacting neurological and neurodegenerative investigations of the human brain.
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Affiliation(s)
- J Jean Chen
- Medical Biophysics, University of Toronto, Toronto, Canada.,Rotman Research Institute, Baycrest, Toronto, Canada
| | - Biranavan Uthayakumar
- Medical Biophysics, University of Toronto, Toronto, Canada.,Sunnybrook Research Institute, Toronto, Canada
| | - Fahmeed Hyder
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, Connecticut, USA.,Department of Radiology, Yale University, New Haven, Connecticut, USA.,Quantitative Neuroscience with Magnetic Resonance (QNMR) Research Program, Yale University, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
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8
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Egnell L, Jerome NP, Andreassen MMS, Bathen TF, Goa PE. Effects of echo time on IVIM quantifications of locally advanced breast cancer in clinical diffusion-weighted MRI at 3 T. NMR IN BIOMEDICINE 2022; 35:e4654. [PMID: 34967468 DOI: 10.1002/nbm.4654] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 09/21/2021] [Accepted: 10/10/2021] [Indexed: 06/14/2023]
Abstract
PURPOSE The purpose of this study was to investigate the effects of echo time dependence in IVIM quantification of the pseudo-diffusion fraction in breast cancer and whether correcting for the echo time dependence offers added clinical value. MATERIALS AND METHODS Fifteen patients with biopsy-proven breast cancer underwent a 3 T MRI examination with an extended DWI protocol at two different echo times (TE = 53 ms, b = 0, 50 s/mm2 ; TE = 77 ms, b = 0, 50, 120, 200, 400, 700 s/mm2 ). Volumes of interest were delineated around the tumors. In addition, simulated MRI data were generated for different levels of signal-to-noise ratio and two values for the blood T2 relaxation time (T2p = 100 ms and 150 ms). The pseudo-diffusion signal fraction was estimated from the simulated and in vivo tumor data using both the standard IVIM model and an extended IVIM model that accounts for the echo time dependence arising from distinct transverse relaxation times. RESULTS Simulations showed that the standard IVIM model overestimated the pseudo-diffusion fraction by 25% (T2p = 100 ms) and 60 % (T2p = 150 ms) (p < 0.0001 at SNR = 50). In vivo, the estimated apparent T2 value at b = 50 s/mm2 was around 8% lower than at b = 0 s/mm2 (p = 0.01) demonstrating a removal of the signal contribution from blood with long T2 associated with pseudo-diffusion. Using two different fixed values for T2p = 100, 150 ms, the pseudo-diffusion fraction was 15% and 46% higher in the standard model compared with the echo-time-corrected model (p < 0.01). CONCLUSION The standard IVIM model was found to overestimate the pseudo-diffusion fraction by 15% to 46% compared with the echo-time-corrected model in breast tumor DWI data acquired at 3 T. Our results suggest that a corrected model may give more accurate results in terms of signal fractions, but may not justify the added time needed to acquire the additional data in terms of clinical value.
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Affiliation(s)
- Liv Egnell
- Department of Physics, NTNU-Norwegian University of Science and Technology, Trondheim, Norway
- Clinic of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway
| | - Neil P Jerome
- Clinic of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway
- Department of Circulation and Medical Imaging, NTNU-Norwegian University of Science and Technology, Trondheim, Norway
| | - Maren M S Andreassen
- Department of Circulation and Medical Imaging, NTNU-Norwegian University of Science and Technology, Trondheim, Norway
| | - Tone F Bathen
- Clinic of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway
- Department of Circulation and Medical Imaging, NTNU-Norwegian University of Science and Technology, Trondheim, Norway
| | - Pål Erik Goa
- Department of Physics, NTNU-Norwegian University of Science and Technology, Trondheim, Norway
- Clinic of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway
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9
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Yoshimura S, Tanaka H, Kawabata S, Kozawa J, Takahashi H, Hidaka Y, Hotta M, Kashiwagi N, Tomiyama N. Effect of urinary glucose concentration and pH on signal intensity in magnetic resonance images. Jpn J Radiol 2022; 40:930-938. [PMID: 35396668 PMCID: PMC8993672 DOI: 10.1007/s11604-022-01273-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/16/2022] [Indexed: 11/26/2022]
Abstract
Purpose With advances in anti-diabetes drugs, increasing numbers of patients have high urinary glucose concentrations, which may alter magnetic resonance (MR) signal intensity. We sought to elucidate the effect of urinary glucose concentration and pH on transverse relaxation and MR signal intensity. Materials and methods The transverse relaxation rate (R2) was measured in samples with different glucose concentrations (in vitro) and in the urinary bladder of seven patients with diabetes and nine healthy volunteers (in vivo). The glucose concentration and pH in the in vitro samples and urine were measured. The signal intensity ratio of the bladder to adjacent tissues was obtained on T2-weighted imaging (WI), T1WI, and MR urography (in vivo). To clarify the effect of pH further, the urine of two healthy subjects was adjusted with acid and/or base to obtain various pH values (ex vivo). Results R2 increased significantly with high glucose concentrations in the in vitro study. In the in vivo study, high glucose concentration (p < 0.001) and low pH (p = 0.005) were significantly associated with high R2. R2 was higher (p = 0.002) and the signal in maximum-intensity projection images of MR urography was lower (p = 0.005) in patients with diabetes than in healthy subjects. Ex vivo study revealed that a decrease in pH in acid portion resulted in increased R2. Conclusion High concentrations of urinary glucose and low pH both enhance transverse relaxation, which, in turn, causes low signal intensity in urinary bladder on long echo time (TE) images, such as MR urography. Radiologists should be aware of this phenomenon when interpreting abnormally low-intensity bladders on long TE images.
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Affiliation(s)
- Sho Yoshimura
- Division of Health Science, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hisashi Tanaka
- Division of Health Science, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Shuichi Kawabata
- Department of Medical Radiological Technology, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Junji Kozawa
- Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroto Takahashi
- Center for Twin Research, Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoh Hidaka
- Laboratory for Clinical Investigation, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Masaki Hotta
- Laboratory for Clinical Investigation, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Nobuo Kashiwagi
- Department of Future Diagnostic Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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10
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Thomas DG, Galvosas P, Tzeng YC, Harrison FG, Berry MJ, Teal PD, Wright GA, Obruchkov S. Oxygen saturation-dependent effects on blood transverse relaxation at low fields. MAGMA (NEW YORK, N.Y.) 2022; 35:805-815. [PMID: 35107697 PMCID: PMC9463268 DOI: 10.1007/s10334-021-00993-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/28/2021] [Accepted: 12/15/2021] [Indexed: 11/28/2022]
Abstract
Objective Blood oxygenation can be measured using magnetic resonance using the paramagnetic effect of deoxy-haemoglobin, which decreases the \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 relaxation time of blood. This \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 contrast has been well characterised at the \documentclass[12pt]{minimal}
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\begin{document}$$\textit{B}_{{0}}$$\end{document}B0 fields used in MRI (1.5 T and above). However, few studies have characterised this effect at lower magnetic fields. Here, the feasibility of blood oximetry at low field based on \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 changes that are within a physiological relevant range is explored. This study could be used for specifying requirements for construction of a monitoring device based on low field permanent magnet systems. Methods A continuous flow circuit was used to control parameters such as oxygen saturation and temperature in a sample of blood. It flowed through a variable field magnet, where CPMG experiments were performed to measure its \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2. In addition, the oxygen saturation was monitored by an optical sensor for comparison with the \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 changes. Results These results show that at low \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 due to oxygenation is small, but still detectable. The data measured at low fields are also in agreement with theoretical models for the oxy-deoxy \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 effect. Conclusion \documentclass[12pt]{minimal}
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\begin{document}$$\textit{T}_{2}$$\end{document}T2 changes in blood due to oxygenation were observed at fields as low as 0.1 T. These results suggest that low field NMR relaxometry devices around 0.3 T could be designed to detect changes in blood oxygenation.
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Affiliation(s)
- Dion G Thomas
- School of Chemical and Physical Sciences and MacDiarmid Institute for Advanced Materials, Victoria University of Wellington, Wellington, New Zealand
| | - Petrik Galvosas
- School of Chemical and Physical Sciences and MacDiarmid Institute for Advanced Materials, Victoria University of Wellington, Wellington, New Zealand
| | - Yu-Chieh Tzeng
- Centre for Translational Research, University of Otago, Wellington, New Zealand
| | - Freya G Harrison
- Centre for Translational Research, University of Otago, Wellington, New Zealand
| | - Mary J Berry
- Centre for Translational Research and Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Paul D Teal
- School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand
| | - Graham A Wright
- Sunnybrook Research Institute and University of Toronto, Toronto, ON, Canada
| | - Sergei Obruchkov
- Robinson Research Institute, Victoria University of Wellington, Wellington, New Zealand.
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11
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Baas KPA, Coolen BF, Petersen ET, Biemond BJ, Strijkers GJ, Nederveen AJ. Comparative Analysis of Blood T 2 Values Measured by T 2 -TRIR and TRUST. J Magn Reson Imaging 2022; 56:516-526. [PMID: 35077595 DOI: 10.1002/jmri.28066] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/24/2021] [Accepted: 12/28/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Venous blood oxygenation (Yv), which can be derived from venous blood T2 (T2 b), combined with oxygen-extraction fraction (OEF) and cerebral metabolic rate of oxygen, is considered indicative for tissue viability and brain functioning and frequently assessed in patients with sickle cell disease. Recently, T2 -Prepared-Blood-Relaxation-Imaging-with-Inversion-Recovery (T2 -TRIR) was introduced allowing for simultaneous measurements of blood T2 and T1 (T1 b), potentially improving Yv estimation by overcoming the need to estimate hematocrit. PURPOSE To optimize and compare T2 -TRIR with T2 -relaxation-under-spin-tagging (TRUST) sequence. STUDY TYPE Prospective. POPULATION A total of 12 healthy volunteers (six female, 27 ± 3 years old) and 7 patients with sickle cell disease (five female, 32 ± 12 years old). FIELD STRENGTH/SEQUENCE 3 T; turbo field echo planar imaging (TFEPI), echo planar imaging (EPI), and fast field echo (FFE). ASSESSMENT T2 b, Yv, and OEF from TRUST and T2 -TRIR were compared and T2 -TRIR-derived T1 b was assessed. Within- and between-session repeatability was quantified in the controls, whereas sensitivity to hemodynamic changes after acetazolamide (ACZ) administration was assessed in the patients. STATISTICAL TESTS Shapiro-Wilk, one-sample and paired-sample t-test, repeated measures ANOVA, mixed linear model, Bland-Altman analysis and correlation analysis. Sidak multiple-comparison correction was performed. Significance level was 0.05. RESULTS In controls, T2 b from T2 -TRIR (70 ± 11 msec) was higher compared to TRUST (60 ± 8 msec). In patients, T2 b values were lower pre- compared to post-ACZ administration (TRUST: 80 ± 15 msec and 106 ± 23 msec and T2 -TRIR: 95 ± 21 msec and 125 ± 36 msec). Consequently, Yv and OEF were lower and higher pre- compared to post-ACZ administration (TRUST Yv: 68% ± 7% and 77% ± 8%, T2 -TRIR Yv: 74% ± 8% and 80% ± 6%, TRUST OEF: 30% ± 7% and 21% ± 8%, and T2 -TRIR OEF: 25% ± 8% and 18% ± 6%). DATA CONCLUSION TRUST and T2 -TRIR are reproducible, but T2 -TRIR-derived T2 b values are significantly higher compared to TRUST, resulting in higher Yv and lower OEF estimates. This bias might be considered when evaluating cerebral oxygen homeostasis. EVIDENCE LEVEL 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Koen P A Baas
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Bram F Coolen
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Esben T Petersen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark.,Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Bart J Biemond
- Department of Hematology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Gustav J Strijkers
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Aart J Nederveen
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
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12
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Ultra-long-TE arterial spin labeling reveals rapid and brain-wide blood-to-CSF water transport in humans. Neuroimage 2021; 245:118755. [PMID: 34826596 PMCID: PMC7612938 DOI: 10.1016/j.neuroimage.2021.118755] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 12/20/2022] Open
Abstract
The study of brain clearance mechanisms is an active area of research. While we know that the cerebrospinal fluid (CSF) plays a central role in one of the main existing clearance pathways, the exact processes for the secretion of CSF and the removal of waste products from tissue are under debate. CSF is thought to be created by the exchange of water and ions from the blood, which is believed to mainly occur in the choroid plexus. This exchange has not been thoroughly studied in vivo. We propose a modified arterial spin labeling (ASL) MRI sequence and image analysis to track blood water as it is transported to the CSF, and to characterize its exchange from blood to CSF. We acquired six pseudo-continuous ASL sequences with varying labeling duration (LD) and post-labeling delay (PLD) and a segmented 3D-GRASE readout with a long echo train (8 echo times (TE)) which allowed separation of the very long-T2 CSF signal. ASL signal was observed at long TEs (793 ms and higher), indicating presence of labeled water transported from blood to CSF. This signal appeared both in the CSF proximal to the choroid plexus and in the subarachnoid space surrounding the cortex. ASL signal was separated into its blood, gray matter and CSF components by fitting a triexponential function with T2s taken from literature. A two-compartment dynamic model was introduced to describe the exchange of water through time and TE. From this, a water exchange time from the blood to the CSF (Tbl->CSF) was mapped, with an order of magnitude of approximately 60 s.
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13
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Bush A, Vu C, Choi S, Borzage M, Miao X, Li W, Qin Q, Nederveen AJ, Coates TD, Wood JC. Calibration of T 2 oximetry MRI for subjects with sickle cell disease. Magn Reson Med 2021; 86:1019-1028. [PMID: 33719133 DOI: 10.1002/mrm.28757] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/14/2021] [Accepted: 02/09/2021] [Indexed: 11/10/2022]
Abstract
PURPOSE Cerebral T2 oximetry is a non-invasive imaging method to measure blood T2 and cerebral venous oxygenation. Measured T2 values are converted to oximetry estimates using carefully validated and potentially disease-specific calibrations. In sickle cell disease, red blood cells have abnormal cell shape and membrane properties that alter T2 oximetry calibration relationships in clinically meaningful ways. Previous in vitro works by two independent groups established potentially competing calibration models. METHODS This study analyzed pooled datasets from these two studies to establish a unified and more robust sickle-specific calibration to serve as a reference standard in the field. RESULTS Even though the combined calibration did not demonstrate statistical superiority compared to previous models, the calibration was unbiased compared to blood-gas co-oximetry and yielded limits of agreement of (-10.1%, 11.6%) in non-transfused subjects with sickle cell disease. In transfused patients, this study proposed a simple correction method based on individual hemoglobin S percentage that demonstrated reduced bias in saturation measurement compared to previous uncorrected sickle calibrations. CONCLUSION The combined calibration is based on a larger range of hematocrit, providing greater confidence in the hematocrit-dependent model parameters, and yielded unbiased estimates to blood-gas co-oximetry measurements from both sites. Additionally, this work also demonstrated the need to correct for transfusion in T2 oximetry measurements for hyper-transfused sickle cell disease patients and proposes a correction method based on patient-specific hemoglobin S concentration.
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Affiliation(s)
- Adam Bush
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Department of Radiology, Stanford University, Stanford, California, USA
| | - Chau Vu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Soyoung Choi
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Matthew Borzage
- Fetal and Neonatal Institute, Division of Neonatology, Children's Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Xin Miao
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Wenbo Li
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Qin Qin
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Aart J Nederveen
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, Amsterdam, the Netherlands
| | - Thomas D Coates
- Division of Hematology-Oncology, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California, USA.,Departments of Pediatrics and Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - John C Wood
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Division of Cardiology, Departments of Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA
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14
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Ruschke S, Syväri J, Dieckmeyer M, Junker D, Makowski MR, Baum T, Karampinos DC. Physiological variation of the vertebral bone marrow water T2 relaxation time. NMR IN BIOMEDICINE 2021; 34:e4439. [PMID: 33205520 DOI: 10.1002/nbm.4439] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study was to investigate physiological variations of the water T2 relaxation time in vertebral bone marrow with respect to age, body mass index (BMI), sex and proton density fat fraction (PDFF) based on single-voxel magnetic resonance spectroscopy (MRS) at 3 T. Multi-TE single-voxel STEAM MRS data of a single lumbar vertebra (L4 or L5) from 260 subjects (160/100 female/male, age: 0.7/37.1/77.7 years, BMI: 13.6/26.2/44.5 kg/m2 [min./median/max.]) with no history of vertebral bone marrow pathologies were retrospectively included. All data were processed using a joint series T2-constrained time domain-based water-fat model. Water T2 and PDFF data were analyzed using (a) Pearson's correlation r and (b) multiple linear regression without interactions of the independent variables. Min./median/max. water T2 and PDFF were 11.2/21.1/42.5 ms and 4.0%/36.8%/82.0%, respectively. Pearson's correlation coefficients were significant (P < .05) for water T2 versus age (r = -0.429/-0.210 female/male) and for water T2 versus PDFF (r = -0.580/-0.546 female/male) for females and males, respectively. Females showed significant higher water T2 values compared with males (P < .001). Multiple linear regression for water T2 without interactions revealed a R2 = 0.407 with PDFF (P < .001) and sex (P < .001) as significant predictors. The current study suggests that under physiological conditions vertebral bone marrow water T2 is negatively correlated with age and PDFF and shows significant differences between females and males. The observed systematic trends are of relevance for the evaluation of T2 values and T2-weighted bone marrow parameters. Further research on the exact mechanisms and drivers of the observed water T2 behavior is required.
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Affiliation(s)
- Stefan Ruschke
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jan Syväri
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Michael Dieckmeyer
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Daniela Junker
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Marcus R Makowski
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Thomas Baum
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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15
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Petitclerc L, Schmid S, Hirschler L, van Osch MJP. Combining T 2 measurements and crusher gradients into a single ASL sequence for comparison of the measurement of water transport across the blood-brain barrier. Magn Reson Med 2020; 85:2649-2660. [PMID: 33252152 PMCID: PMC7898618 DOI: 10.1002/mrm.28613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 02/01/2023]
Abstract
Purpose Arterial spin labeling can be used to assess the transition time of water molecules across the blood–brain barrier when combined with sequence modules, which allow a separation of intravascular from tissue signal. The bipolar gradient technique measures the intravascular fraction by removing flowing spins. The T2‐relaxation‐under‐spin‐tagging (TRUST) technique modulates the TE to differentiate between intravascular and extravascular spins based on T2. These modules were combined into a single time‐encoded pseudo‐continuous arterial spin labeling sequence to compare their mechanisms of action as well as their assessment of water transition across the blood–brain barrier. Methods This protocol was acquired on a scanner with 9 healthy volunteers who provided written, informed consent. The sequence consisted of a Hadamard‐encoded pseudo‐continuous arterial spin labeling module, followed by the TRUST module (effective TEs of 0, 40, and 80 ms) and bipolar flow‐crushing gradients (2, 4, and ∞ cm/s). An additional experiment was performed with TRUST and a 3D gradient and spin‐echo readout. Results Gradients imperfectly canceled the intravascular signal, as evidenced by the presence of residual signal in the arteries at early postlabeling delays as well as the underestimation of the intravascular fraction as compared with the TRUST method. The TRUST module allowed us to detect the transport of water deeper into the vascular tree through changes in T2 than the used crusher gradients could, with their limited b‐value. Conclusion Of the implemented techniques, TRUST allowed us to follow intravascular signal deeper into the vascular tree than the approach with (relatively weak) crusher gradients when quantifying the transport time of water across the blood–brain barrier.
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Affiliation(s)
- Léonie Petitclerc
- Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden, Netherlands
| | - Sophie Schmid
- Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden, Netherlands
| | - Lydiane Hirschler
- Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - Matthias J P van Osch
- Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,Leiden Institute for Brain and Cognition, Leiden, Netherlands
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16
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Schidlowski M, Boland M, Rüber T, Stöcker T. Blood-brain barrier permeability measurement by biexponentially modeling whole-brain arterial spin labeling data with multiple T 2 -weightings. NMR IN BIOMEDICINE 2020; 33:e4374. [PMID: 32715563 DOI: 10.1002/nbm.4374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
Blood-brain barrier (BBB) permeability assessment remains of ongoing interest in clinical practice and research. Transitions between intravascular (IV) and extravascular (EV) gray matter (GM) compartments may provide information regarding the microstructural status of the BBB. Due to different transverse relaxation times (T2 ) of water protons in vessels and GM, it is possible to determine the compartment in which these protons are located. This work presents and investigates the feasibility of a simplified analytical approach for compartmentalizing the proportions of magnetically marked water protons into IV and EV GM components by biexponentially modeling T2 -weighted arterial spin labeling (ASL) data. Numerous model assumptions were used to stabilize the fit and achieve in vivo applicability. Particularly, transverse relaxation times of IV and EV water protons were determined from the analysis of two supporting T2 -weighted ASL measurements, utilizing a monoexponential signal model. This stabilized a two-parameter biexponential fit of ASL data with T2 preparation (PLD = 0.9/1.2/1.5/1.8 s, TET2Prep = 0/30/40/60/80/120/160 ms), which thereby robustly provided estimates of the IV and EV compartment fractions. Experiments were conducted with three healthy volunteers in a 3 T scanner. Averaged over all subjects, the labeled water protons inherit T2,IV = 200 ± 18 ms initially and adapt T2,EV = 91 ± 2 ms with a longer retention time in cerebral structures. Accordingly, the EVlocated ASL signal fraction rises with increasing PLD from 0.31 ± 0.11 at the shortest PLD of 0.9 s to 0.73 ± 0.02 at the longest PLD of 1.8s. These results indicate a transition of the water protons from IV to EV space. The findings support the potential of biexponential modeling for compartmentalizing ASL spin fractions between IV and EV space. The novel integration of monoexponential parameter estimates stabilizes the two-compartment model fit, suggesting that this technique is suitable for robustly estimating the BBB permeability in vivo.
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Affiliation(s)
- Martin Schidlowski
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Markus Boland
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Theodor Rüber
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe University Frankfurt, Frankfurt/Main, Germany
- Center for Personalized Translational Epilepsy Research (CePTER), Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Tony Stöcker
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Department for Physics and Astronomy, University of Bonn, Bonn, Germany
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Zhao L, Taso M, Dai W, Press DZ, Alsop DC. Non-invasive measurement of choroid plexus apparent blood flow with arterial spin labeling. Fluids Barriers CNS 2020; 17:58. [PMID: 32962708 PMCID: PMC7510126 DOI: 10.1186/s12987-020-00218-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023] Open
Abstract
Background The choroid plexus is a major contributor to the generation of cerebrospinal fluid (CSF) and the maintenance of its electrolyte and metabolite balance. Here, we sought to characterize the blood flow dynamics of the choroid plexus using arterial spin labeling (ASL) MRI to establish ASL as a non-invasive tool for choroid plexus function and disease studies. Methods Seven healthy volunteers were imaged on a 3T MR scanner. ASL images were acquired with 12 labeling durations and post labeling delays. Regions of the choroid plexus were manually segmented on high-resolution T1 weighted images. Choroid plexus perfusion was characterized with a dynamic ASL perfusion model. Cerebral gray matter perfusion was also quantified for comparison. Results Kinetics of the ASL signal were clearly different in the choroid plexus than in gray matter. The choroid plexus has a significantly longer T1 than the gray matter (2.33 ± 0.30 s vs. 1.85 ± 0.10 s, p < 0.02). The arterial transit time was 1.24 ± 0.20 s at the choroid plexus. The apparent blood flow to the choroid plexus was measured to be 39.5 ± 10.1 ml/100 g/min and 0.80 ± 0.31 ml/min integrated over the posterior lateral ventricles in both hemispheres. Correction with the choroid plexus weight yielded a blood flow of 80 ml/100 g/min. Conclusions Our findings suggest that ASL can provide a clinically feasible option to quantify the dynamic characteristics of choroid plexus blood flow. It also provides useful reference values of the choroid plexus perfusion. The long T1 of the choroid plexus may suggest the transport of water from arterial blood to the CSF, potentially providing a method to quantify CSF generation.
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Affiliation(s)
- Li Zhao
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Manuel Taso
- Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Weiying Dai
- Computer Science, State University of New York At Binghamton, Binghamton, NY, USA
| | - Daniel Z Press
- Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - David C Alsop
- Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
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Li W, van Zijl PC. Quantitative theory for the transverse relaxation time of blood water. NMR IN BIOMEDICINE 2020; 33:e4207. [PMID: 32022362 PMCID: PMC7322972 DOI: 10.1002/nbm.4207] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/19/2019] [Accepted: 10/01/2019] [Indexed: 05/08/2023]
Abstract
An integrative model is proposed to describe the dependence of the transverse relaxation rate of blood water protons (R2blood = 1/T2blood ) on hematocrit fraction and oxygenation fraction (Y). This unified model takes into account (a) the diamagnetic effects of albumin, hemoglobin and the cell membrane; (b) the paramagnetic effect of hemoglobin; (c) the effect of compartmental exchange between plasma and erythrocytes under both fast and slow exchange conditions that vary depending on field strength and compartmental relaxation rates and (d) the effect of diffusion through field gradients near the erythrocyte membrane. To validate the model, whole-blood and lysed-blood R2 data acquired previously using Carr-Purcell-Meiboom-Gill measurements as a function of inter-echo spacing τcp at magnetic fields of 3.0, 7.0, 9.4 and 11.7 T were fitted to determine the lifetimes (field-independent physiological constants) for water diffusion and exchange, as well as several physical constants, some of which are field-independent (magnetic susceptibilities) and some are field-dependent (relaxation rates for water protons in solutions of albumin and oxygenated and deoxygenated hemoglobin, ie, blood plasma and erythrocytes, respectively). This combined exchange-diffusion model allowed excellent fitting of the curve of the τcp -dependent relaxation rate dispersion at all four fields using a single average erythrocyte water lifetime, τery = 9.1 ± 1.4 ms, and an averaged diffusional correlation time, τD = 3.15 ± 0.43 ms. Using this model and the determined physiological time constants and relaxation parameters, blood T2 values published by multiple groups based on measurements at magnetic field strengths of 1.5 T and higher could be predicted correctly within error. Establishment of this theory is a fundamental step for quantitative modeling of the BOLD effect underlying functional MRI.
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Affiliation(s)
- Wenbo Li
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Peter C.M. van Zijl
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
- Correspondence: Peter C.M. van Zijl, PhD, F. M. Kirby Research Center for Functional Brain Imaging, The Kennedy Krieger Institute, 707 N. Broadway, Room G-25, Baltimore, MD, 21205, United States of America, , Tel: 443-923-9500, Fax: 443-923-9505
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Hermann I, Uhrig T, Chacon-Caldera J, Akçakaya M, Schad LR, Weingärtner S. Towards measuring the effect of flow in blood T 1 assessed in a flow phantom and in vivo. Phys Med Biol 2020; 65:095001. [PMID: 32160594 DOI: 10.1088/1361-6560/ab7ef1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Measurement of the blood T 1 time using conventional myocardial T 1 mapping methods has gained clinical significance in the context of extracellular volume (ECV) mapping and synthetic hematocrit (Hct). However, its accuracy is potentially compromised by in-flow of non-inverted/non-saturated spins and in-flow of spins which are not partially saturated from previous imaging pulses. Bloch simulations were used to analyze various flow effects separately. T 1 measurements of gadolinium doped water were performed using a flow phantom with adjustable flow velocities at 3 T. Additionally, in vivo blood T 1 measurements were performed in 6 healthy subjects (26 ± 5 years, 2 female). To study the T 1 time as a function of the instantaneous flow velocity, T 1 times were evaluated in an axial imaging slice of the descending aorta. Velocity encoded cine measurements were performed to quantify the flow velocity throughout the cardiac cycle. Simulation results show more than 30% loss in accuracy for 10% non-prepared in-flowing spins. However, in- and out-flow to the imaging plane only demonstrated minor impact on the T 1 time. Phantom T 1 times were decreased by up to 200 ms in the flow phantom, due to in-flow of non-prepared spins. High flow velocities cause in-flow of spins that lack partial saturation from the imaging pulses but only lead to negligible T 1 time deviation (less than 30 ms). In vivo measurements confirm a substantial variation of the T 1 time depending on the flow velocity. The highest aortic T 1 times are observed at the time point of minimal flow with increased flow velocity leading to reduction of the measured T 1 time by up to [Formula: see text] at peak velocity. In this work we attempt to dissect the effects of flow on T 1 times, by using simulations, well-controlled, simplified phantom setup and the linear flow pattern in the descending aorta in vivo.
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Affiliation(s)
- Ingo Hermann
- Magnetic Resonance Systems Lab, Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 Delft, Netherlands. Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
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20
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Robust single-shot acquisition of high resolution whole brain ASL images by combining time-dependent 2D CAPIRINHA sampling with spatio-temporal TGV reconstruction. Neuroimage 2019; 206:116337. [PMID: 31707191 PMCID: PMC6980903 DOI: 10.1016/j.neuroimage.2019.116337] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/24/2019] [Accepted: 11/04/2019] [Indexed: 12/04/2022] Open
Abstract
For ASL perfusion imaging in clinical settings the current guidelines recommends pseudo-continuous arterial spin labeling with segmented 3D readout. This combination achieves the best signal to noise ratio with reasonable resolution but is prone to motion artifacts due to the segmented readout. Motion robust single-shot 3D acquisitions suffer from image blurring due to the T2 decay of the sampled signals during the long readout. To tackle this problem, we propose an accelerated 3D-GRASE sequence with a time-dependent 2D-CAIPIRINHA sampling pattern. This has several advantages: First, the single-shot echo trains are shortened by the acceleration factor; Second, the temporal incoherence between measurements is increased; And third, the coil sensitivity maps can be estimated directly from the averaged k-space data. To obtain improved perfusion images from the undersampled time series, we developed a variational image reconstruction approach employing spatio-temporal total-generalized-variation (TGV) regularization. The proposed ASL-TGV method reduced the total acquisition time, improved the motion robustness of 3D ASL data, and the image quality of the cerebral blood flow (CBF) maps compared to those by a standard segmented approach. An evaluation was performed on 5 healthy subjects including intentional movement for 2 subjects. Single-shot whole brain CBF-maps with high resolution3.1 × 3.1 × 3 mm and image quality can be acquired in 1min 46sec. Additionally high quality CBF- and arterial transit time (ATT) -maps from single-shot multi-post-labeling delay (PLD) data can be gained with the proposed method. This method may improve the robustness of 3D ASL in clinical settings, and may be applied for perfusion fMRI.
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Wengler K, Fukuda T, Tank D, Komatsu DE, Paulus M, Huang M, Gould ES, Schweitzer ME, He X. In vivo evaluation of human patellar tendon microstructure and microcirculation with diffusion MRI. J Magn Reson Imaging 2019; 51:780-790. [PMID: 31407413 DOI: 10.1002/jmri.26898] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/25/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Patellar tendon (PT) microstructure integrity and microcirculation status play a crucial role in the progression of tendinopathy and tendon repair. PURPOSE To assess the feasibility and robustness of stimulated-echo based diffusion-weighted MRI with readout-segmented echo-planar imaging (ste-RS-EPI) for noninvasive assessment of microstructure and microcirculation of human PT. STUDY TYPE Prospective. SUBJECTS Fifteen healthy volunteers. FIELD STRENGTH/SEQUENCE PT diffusion tensor imaging (DTI) and intravoxel incoherent motion (IVIM) were acquired with an ste-RS-EPI protocol on a 3T MRI scanner. ASSESSMENT Subjects were positioned with their PT at the magic angle. DTI-derived parameters including axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), and fractional anisotropy (FA) were estimated with b-values of 0 and 800 s/mm2 and 12 diffusion directions. IVIM-derived parameters, f p , D* × f p , V b , and D* × V b were assessed in the central-third and the outer-two thirds of the PT with b-values of 0, 20, 30, 60, 80, 120, 200, 400, and 600 s/mm2 in three orthogonal directions. STATISTICAL TESTS Paired t-tests were used to evaluate differences in IVIM parameters between the central-third and outer-two thirds regions of the patellar tendon. Paired t-tests and within-subject coefficient of variation were used to assess the intra- and intersession reproducibility of PT DTI and IVIM parameters. RESULTS DTI parameters for healthy PT were 1.54 ± 0.09 × 10-3 mm2 /s, 1.01 ± 0.05 × 10-3 mm2 /s, 1.18 ± 0.06 × 10-3 mm2 /s, and 0.30 ± 0.04 for AD, RD, MD, and FA, respectively. Significantly higher (P < 0.05) IVIM parameters f p and D* × f p were observed in the outer-two thirds (6.1% ± 2.4% and 95.2 ± 49.6, respectively) compared with the central-third (3.8% ± 2.3% and 48.6 ± 35.2, respectively) of the PT. DATA CONCLUSION Diffusion MRI of PT with an ste-RS-EPI protocol is clinically feasible. Both DTI- and IVIM-derived parameters of the PT demonstrated good test-retest reproducibility and interrater reliability. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:780-790.
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Affiliation(s)
- Kenneth Wengler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Takeshi Fukuda
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Dharmesh Tank
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - David E Komatsu
- Department of Orthopaedics, Stony Brook University, Stony Brook, New York, USA
| | - Megan Paulus
- Department of Orthopaedics, Stony Brook University, Stony Brook, New York, USA
| | - Mingqian Huang
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Elaine S Gould
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Mark E Schweitzer
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Xiang He
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
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22
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Lin Z, Sur S, Soldan A, Pettigrew C, Miller M, Oishi K, Bilgel M, Moghekar A, Pillai JJ, Albert M, Lu H. Brain Oxygen Extraction by Using MRI in Older Individuals: Relationship to Apolipoprotein E Genotype and Amyloid Burden. Radiology 2019; 292:140-148. [PMID: 31012816 DOI: 10.1148/radiol.2019182726] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Background Apolipoprotein E4 (APOE4) is a major genetic risk factor for late-onset Alzheimer disease. However, the mechanisms by which APOE4 affects the brain, underpinning this risk, have not been fully elucidated. Purpose To investigate the influence of APOE4 on global cerebral oxygen extraction fraction (OEF) and possible mediation through amyloid burden by using MRI-based brain oxygen extraction technique. Materials and Methods Participants were enrolled from a longitudinal prospective study, the Biomarkers for Older Controls at Risk for Dementia study (data collected from January 2015 to December 2017), of whom 35% (50 of 143 participants) were APOE4 carriers. OEF was measured by using a T2-relaxation-under-spin-tagging MRI technique with a 3.0-T MRI system. PET acquired with carbon 11-labeled Pittsburgh compound B tracer was available in 119 participants to measure amyloid burden. Cognitive performance was assessed by using domain-specific composite scores including executive function, episodic memory, visual-spatial processing, and language. Linear regression analysis was performed to investigate the relationship between APOE4, OEF, and amyloid burden. The association between OEF and cognitive function was studied for the entire study cohort and separately for the APOE4 carriers and noncarriers. Results A total of 143 cognitively healthy individuals (mean age 6 standard deviation, 69.1 years 6 8.2; 57 men and 86 women) were studied. APOE4 genetic status was associated with lower OEF (noncarriers, 41.1% 6 5.8; one E4 allele, 40.1% 6 4.9; two E4 alleles, 36.7% 6 4.5; P = .03). Furthermore, among APOE4 carriers, lower OEF correlated with lower executive function scores (b = 0.079 z score for each percent change in OEF; P = .03). Amyloid burden and OEF were independently associated with APOE4 but were not associated with one another, suggesting that the effect of APOE4 on OEF is not mediated by amyloid. Conclusion MRI-based brain oxygen extraction shows that cognitively healthy carriers of the apolipoprotein E4 gene manifest diminished brain oxygen extraction capacity independent of amyloid burden. ©RSNA, 2019 Online supplemental material is available for this article.
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Affiliation(s)
- Zixuan Lin
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Sandeepa Sur
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Anja Soldan
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Corinne Pettigrew
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Michael Miller
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Kenichi Oishi
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Murat Bilgel
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Abhay Moghekar
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Jay J Pillai
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Marilyn Albert
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
| | - Hanzhang Lu
- From the Department of Biomedical Engineering (Z.L., M.M., H.L.), The Russell H. Morgan Department of Radiology and Radiological Science (Z.L., S.S., K.O., J.J.P., H.L.), and Department of Neurology (A.S., C.P., A.M., M.A.), Johns Hopkins University School of Medicine, 600 N Wolfe St, Park 322, Baltimore, Md; Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Md (M.B.); and F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Md (H.L.)
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Characterizing contrast origins and noise contribution in spin-echo EPI BOLD at 3 T. Magn Reson Imaging 2019; 57:328-336. [DOI: 10.1016/j.mri.2018.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/06/2018] [Accepted: 11/11/2018] [Indexed: 11/18/2022]
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Suzuki Y, van Osch MJP, Fujima N, Okell TW. Optimization of the spatial modulation function of vessel-encoded pseudo-continuous arterial spin labeling and its application to dynamic angiography. Magn Reson Med 2018; 81:410-423. [PMID: 30230589 DOI: 10.1002/mrm.27418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/09/2018] [Accepted: 06/01/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE In vessel-encoded pseudo-continuous arterial spin labeling (ve-pCASL), vessel-selective labeling is achieved by modulation of the inversion efficiency across space. However, the spatial transition between the labeling and control conditions is rather gradual, which can cause partial labeling of vessels, reducing SNR-efficiency and necessitating complex postprocessing to decode the vessel-selective signals. The purpose of this study is to optimize the pCASL labeling parameters to obtain a sharper spatial inversion profile of the labeling and thereby minimizing the risk of partial labeling of untargeted arteries. METHODS Bloch simulations were performed to investigate how the inversion profile was influenced by the pCASL labeling parameters: the maximum (Gmax ) and mean (Gmean ) labeling gradient were varied for ve-pCASL with unipolar and bipolar gradients. The findings in the simulation study were subsequently confirmed in an in vivo volunteer study. Moreover, conventional and optimized settings were compared for 4D-MRA using four-cycle Hadamard ve-pCASL; the visualization of arteries and the presence of the partial labeling were assessed by an expert observer. RESULTS When using unipolar gradient, lower Gmean resulted in a steeper spatial transition, whereas the width of the control region was broader for higher Gmax . The in vivo study confirmed these findings. When using bipolar gradients, the control region was always very narrow. Qualitative comparison of the 4D-MRA demonstrated lower occurrence of partial labeling when using the optimized gradient parameters. CONCLUSION The shape of the ve-pCASL inversion profile can be optimized by changing Gmean and Gmax to reduce partial labeling of untargeted arteries.
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Affiliation(s)
- Yuriko Suzuki
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Matthias J P van Osch
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Noriyuki Fujima
- Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Hokkaido, Japan
| | - Thomas W Okell
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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25
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Lemberskiy G, Fieremans E, Veraart J, Deng FM, Rosenkrantz AB, Novikov DS. Characterization of prostate microstructure using water diffusion and NMR relaxation. FRONTIERS IN PHYSICS 2018; 6:91. [PMID: 30568939 PMCID: PMC6296484 DOI: 10.3389/fphy.2018.00091] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
For many pathologies, early structural tissue changes occur at the cellular level, on the scale of micrometers or tens of micrometers. Magnetic resonance imaging (MRI) is a powerful non-invasive imaging tool used for medical diagnosis, but its clinical hardware is incapable of reaching the cellular length scale directly. In spite of this limitation, microscopic tissue changes in pathology can potentially be captured indirectly, from macroscopic imaging characteristics, by studying water diffusion. Here we focus on water diffusion and NMR relaxation in the human prostate, a highly heterogeneous organ at the cellular level. We present a physical picture of water diffusion and NMR relaxation in the prostate tissue, that is comprised of a densely-packed cellular compartment (composed of stroma and epithelium), and a luminal compartment with almost unrestricted water diffusion. Transverse NMR relaxation is used to identify fast and slow T 2 components, corresponding to these tissue compartments, and to disentangle the luminal and cellular compartment contributions to the temporal evolution of the overall water diffusion coefficient. Diffusion in the luminal compartment falls into the short-time surface-to-volume (S/V) limit, indicating that only a small fraction of water molecules has time to encounter the luminal walls of healthy tissue; from the S/V ratio, the average lumen diameter averaged over three young healthy subjects is measured to be 217.7±188.7 μm. Conversely, the diffusion in the cellular compartment is highly restricted and anisotropic, consistent with the fibrous character of the stromal tissue. Diffusion transverse to these fibers is well described by the random permeable barrier model (RPBM), as confirmed by the dynamical exponent ϑ = 1/2 for approaching the long-time limit of diffusion, and the corresponding structural exponent p = -1 in histology. The RPBM-derived fiber diameter and membrane permeability were 19.8±8.1 μm and 0.044±0.045 μm/ms, respectively, in agreement with known values from tissue histology and membrane biophysics. Lastly, we revisited 38 prostate cancer cases from a recently published study, and found the same dynamical exponent ϑ = 1/2 of diffusion in tumors and benign regions. Our results suggest that a multi-parametric MRI acquisition combined with biophysical modeling may be a powerful non-invasive complement to prostate cancer grading, potentially foregoing biopsies.
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Affiliation(s)
- Gregory Lemberskiy
- Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, USA; Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, USA
| | - Els Fieremans
- Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, USA,
| | - Jelle Veraart
- Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, USA,
| | - Fang-Ming Deng
- Department of Pathology, New York University Langone Medical Center, New York, NY New York, NY, USA;
| | - Andrew B Rosenkrantz
- Department of Radiology, New York University Langone Medical Center, New York, NY New York, NY, USA;
| | - Dmitry S Novikov
- Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, USA,
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26
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Milani B, Ledoux JB, Rotzinger DC, Kanemitsu M, Vallée JP, Burnier M, Pruijm M. Image acquisition for intravoxel incoherent motion imaging of kidneys should be triggered at the instant of maximum blood velocity: evidence obtained with simulations and in vivo experiments. Magn Reson Med 2018; 81:583-593. [DOI: 10.1002/mrm.27393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Bastien Milani
- Département de Medecine, Service de Néphrologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
- Département de Radiologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
- Center for Biomedical Imaging; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
| | - Jean-Baptiste Ledoux
- Département de Radiologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
- Center for Biomedical Imaging; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
| | - David C. Rotzinger
- Département de Radiologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
| | - Michiko Kanemitsu
- Département de Medecine, Service de Néphrologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
| | - Jean-Paul Vallée
- Département d'Imagerie et des Sciences de l'information Médicale; Hôpitaux Universitaires de Genève; Genève Switzerland
| | - Michel Burnier
- Département de Medecine, Service de Néphrologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
| | - Menno Pruijm
- Département de Medecine, Service de Néphrologie; Centre Hospitalier Universitaire Vaudois; Vaud Switzerland
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Chu PP, Golestani AM, Kwinta JB, Khatamian YB, Chen JJ. Characterizing the modulation of resting-state fMRI metrics by baseline physiology. Neuroimage 2018; 173:72-87. [DOI: 10.1016/j.neuroimage.2018.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 12/18/2022] Open
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Wengler K, Fukuda T, Tank D, Huang M, Gould ES, Schweitzer ME, He X. Intravoxel incoherent motion (IVIM) imaging in human achilles tendon. J Magn Reson Imaging 2018; 48:1690-1699. [PMID: 29741808 DOI: 10.1002/jmri.26182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/19/2018] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Limited microcirculation has been implicated in Achilles tendinopathy and may affect healing and disease progression. Existing invasive and noninvasive approaches to evaluate tendon microcirculation lack sensitivity and spatial coverage. PURPOSE To develop a novel Achilles tendon intravoxel incoherent motion (IVIM) MRI protocol to overcome the limitations from low tendon T2 /T2 * value and low intratendinous blood volume and blood velocity to evaluate tendon microcirculation. STUDY TYPE Prospective. SUBJECTS Sixteen healthy male participants (age 31.0 ± 2.1) were recruited. FIELD STRENGTH/SEQUENCE A stimulated echo readout-segmented echo planar imaging (ste-RS-EPI) IVIM sequence at 3.0T. ASSESSMENT The feasibility of the proposed ste-RS-EPI IVIM protocol combined with Achilles tendon magic angle effect was evaluated. The sensitivity of the protocol was assessed by an exercise-induced intratendinous hemodynamic response in healthy participants. The vascular origin of the observed IVIM signal was validated by varying the diffusion mixing time and echo time. STATISTICAL TESTS Two-tailed t-tests were used to evaluate differences (P < 0.05 was considered significant). RESULTS Consistent with known tendon hypovascularity, the midportion Achilles tendon at baseline showed significantly lower IVIM-derived perfusion fraction (fp ) (3.1 ± 0.9%) compared to the proximal and distal Achilles tendon (6.0 ± 1.8% and 6.1 ± 2.0%, respectively; P < 0.01). Similarly, the midportion Achilles tendon exhibited significantly lower baseline blood flow index (D*×fp ) (40.9 ± 19.2, 18.3 ± 5.3, and 32.0 ± 9.4 in proximal, midportion, and distal Achilles tendon, respectively; P < 0.01). Eccentric heel-raise exercise led to ∼2 times increase of Achilles tendon blood flow in healthy participants. Consistent with its vascular origin, the estimated fp demonstrated a high dependency to IVIM protocol parameters, while the T1 /T2 -corrected absolute intratendinous microvascular blood volume fraction (Vb ) did not vary. DATA CONCLUSION Achilles tendon ste-RS-EPI IVIM noninvasively assessed baseline values and exercise-induced changes to tendon microcirculation in healthy tendon. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1690-1699.
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Affiliation(s)
- Kenneth Wengler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Takeshi Fukuda
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Dharmesh Tank
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Mingqian Huang
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Elaine S Gould
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Mark E Schweitzer
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
| | - Xiang He
- Department of Radiology, Stony Brook University, Stony Brook, New York, USA
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Funck C, Laun FB, Wetscherek A. Characterization of the diffusion coefficient of blood. Magn Reson Med 2018; 79:2752-2758. [PMID: 28940621 PMCID: PMC5836916 DOI: 10.1002/mrm.26919] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/27/2017] [Accepted: 08/22/2017] [Indexed: 12/13/2022]
Abstract
PURPOSE To characterize the diffusion coefficient of human blood for accurate results in intravoxel incoherent motion imaging. METHODS Diffusion-weighted MRI of blood samples from 10 healthy volunteers was acquired with a single-shot echo-planar-imaging sequence at body temperature. Effects of gradient profile (monopolar or flow-compensated), diffusion time (40-100 ms), and echo time (60-200 ms) were investigated. RESULTS Although measured apparent diffusion coefficients of blood were larger for flow-compensated than for monopolar gradients, no dependence of the apparent diffusion coefficient on the diffusion time was found. Large differences between individual samples were observed, with results ranging from 1.26 to 1.66 µm2 /ms for flow-compensated and 0.94 to 1.52 µm2 /ms for monopolar gradients. Statistical analysis indicates correlations of the flow-compensated apparent diffusion coefficient with hematocrit (P = 0.007) and hemoglobin (P = 0.017), but not with mean corpuscular volume (P = 0.64). Results of Monte-Carlo simulations support the experimental observations. CONCLUSIONS Measured blood apparent diffusion coefficient values depend on hematocrit/hemoglobin concentration and applied gradient profile due to non-Gaussian diffusion. Because in vivo measurement is delicate, an estimation based on blood count results could be an alternative. For intravoxel incoherent motion modeling, the use of a blood self-diffusion constant Db = 1.54 ± 0.12 µm2 /ms for flow-compensated and Db = 1.30 ± 0.18 µm2 /ms for monopolar encoding is suggested. Magn Reson Med 79:2752-2758, 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)
- Carsten Funck
- Medical Physics in Radiology, German Cancer Research Center (DKFZ)HeidelbergGermany
| | - Frederik Bernd Laun
- Medical Physics in Radiology, German Cancer Research Center (DKFZ)HeidelbergGermany
- Institute of RadiologyUniversity Hospital ErlangenErlangenGermany
| | - Andreas Wetscherek
- Medical Physics in Radiology, German Cancer Research Center (DKFZ)HeidelbergGermany
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUnited Kingdom
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30
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Berman AJ, Mazerolle EL, MacDonald ME, Blockley NP, Luh WM, Pike GB. Gas-free calibrated fMRI with a correction for vessel-size sensitivity. Neuroimage 2018; 169:176-188. [DOI: 10.1016/j.neuroimage.2017.12.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 12/11/2017] [Accepted: 12/14/2017] [Indexed: 10/18/2022] Open
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31
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Berman AJL, Pike GB. Transverse signal decay under the weak field approximation: Theory and validation. Magn Reson Med 2017; 80:341-350. [PMID: 29194739 DOI: 10.1002/mrm.27035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE To derive an expression for the transverse signal time course from systems in the motional narrowing regime, such as water diffusing in blood. This was validated in silico and experimentally with ex vivo blood samples. METHODS A closed-form solution (CFS) for transverse signal decay under any train of refocusing pulses was derived using the weak field approximation. The CFS was validated via simulations of water molecules diffusing in the presence of spherical perturbers, with a range of sizes and under various pulse sequences. The CFS was compared with more conventional fits assuming monoexponential decay, including chemical exchange, using ex vivo blood Carr-Purcell-Meiboom-Gill data. RESULTS From simulations, the CFS was shown to be valid in the motional narrowing regime and partially into the intermediate dephasing regime, with increased accuracy with increasing Carr-Purcell-Meiboom-Gill refocusing rate. In theoretical calculations of the CFS, fitting for the transverse relaxation rate (R2 ) gave excellent agreement with the weak field approximation expression for R2 for Carr-Purcell-Meiboom-Gill sequences, but diverged for free induction decay. These same results were confirmed in the ex vivo analysis. CONCLUSION Transverse signal decay in the motional narrowing regime can be accurately described analytically. This theory has applications in areas such as tissue iron imaging, relaxometry of blood, and contrast agent imaging. Magn Reson Med 80:341-350, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Avery J L Berman
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - G Bruce Pike
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
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32
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T 2 mapping of cerebrospinal fluid: 3 T versus 7 T. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 31:415-424. [PMID: 29110239 PMCID: PMC5973950 DOI: 10.1007/s10334-017-0659-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/22/2017] [Accepted: 10/13/2017] [Indexed: 12/03/2022]
Abstract
Object Cerebrospinal fluid (CSF) T2 mapping can potentially be used to investigate CSF composition. A previously proposed CSF T2–mapping method reported a T2 difference between peripheral and ventricular CSF, and suggested that this reflected different CSF compositions. We studied the performance of this method at 7 T and evaluated the influence of partial volume and B1 and B0 inhomogeneity. Materials and methods T2-preparation-based CSF T2-mapping was performed in seven healthy volunteers at 7 and 3 T, and was compared with a single echo spin-echo sequence with various echo times. The influence of partial volume was assessed by our analyzing the longest echo times only. B1 and B0 maps were acquired. B1 and B0 dependency of the sequences was tested with a phantom. Results T2,CSF was shorter at 7 T compared with 3 T. At 3 T, but not at 7 T, peripheral T2,CSF was significantly shorter than ventricular T2,CSF. Partial volume contributed to this T2 difference, but could not fully explain it. B1 and B0 inhomogeneity had only a very limited effect. T2,CSF did not depend on the voxel size, probably because of the used method to select of the regions of interest. Conclusion CSF T2 mapping is feasible at 7 T. The shorter peripheral T2,CSF is likely a combined effect of partial volume and CSF composition. Electronic supplementary material The online version of this article (doi:10.1007/s10334-017-0659-3) contains supplementary material, which is available to authorized users.
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33
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Portnoy S, Milligan N, Seed M, Sled JG, Macgowan CK. Human umbilical cord blood relaxation times and susceptibility at 3 T. Magn Reson Med 2017; 79:3194-3206. [DOI: 10.1002/mrm.26978] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/01/2017] [Accepted: 09/27/2017] [Indexed: 12/30/2022]
Affiliation(s)
- Sharon Portnoy
- Department of Medical Biophysics; University of Toronto; Toronto Ontario Canada
- Mouse Imaging Centre; Hospital for Sick Children; Toronto Ontario Canada
| | - Natasha Milligan
- Department of Obstetrics & Gynecology; Mount Sinai Hospital; Toronto Ontario Canada
| | - Mike Seed
- Division of Cardiology; Hospital for Sick Children; Toronto Ontario Canada
- Department of Pediatrics and Diagnostic Imaging; University of Toronto; Toronto Ontario Canada
| | - John G. Sled
- Department of Medical Biophysics; University of Toronto; Toronto Ontario Canada
- Mouse Imaging Centre; Hospital for Sick Children; Toronto Ontario Canada
- Department of Obstetrics and Gynecology; University of Toronto; Toronto Ontario Canada
| | - Christopher K. Macgowan
- Department of Medical Biophysics; University of Toronto; Toronto Ontario Canada
- Division of Translational Medicine; Hospital for Sick Children; Toronto Ontario Canada
- Labatt Family Heart Centre; Hospital for Sick Children; Toronto Ontario Canada
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Koktzoglou I, Edelman RR. Radial fast interrupted steady-state (FISS) magnetic resonance imaging. Magn Reson Med 2017; 79:2077-2086. [PMID: 28856788 DOI: 10.1002/mrm.26881] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 11/06/2022]
Abstract
PURPOSE To report a highly interrupted radial variant of balanced steady-state free precession (bSSFP) imaging, termed fast interrupted steady-state (FISS), for decreasing flow artifact as well as fat signal conspicuity with respect to bSSFP, and saturation effects vis-à-vis fast low-angle shot (FLASH) imaging. METHODS Numerical simulations, phantom studies, and human studies were conducted to examine the imaging contrast, off-resonance behavior, and flow properties of FISS. Human studies applied FISS for cine cardiac imaging and ungated nonenhanced MR angiography (MRA) of the legs, neck, and brain. Comparisons were made with bSSFP and FLASH imaging. RESULTS Simulations revealed that FISS retains the high signal levels of bSSFP for stationary on-resonant spins, while reducing undesirable signal heterogeneity from flowing spins. Phantom studies agreed with the simulations, and showed that FISS reduces fat signal and flow artifact with respect to bSSFP imaging. FISS imaging in human subjects agreed with the simulations and phantom studies, and showed reduced saturation artifact compared with FLASH imaging. CONCLUSION FISS imaging reduces flow artifact and fat signal conspicuity with respect to bSSFP imaging, and ameliorates arterial signal saturation observed with FLASH imaging. Potential clinical applications include fat-suppressed cine imaging and ungated nonenhanced MRA. Magn Reson Med 79:2077-2086, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Robert R Edelman
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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35
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Vidorreta M, Wang Z, Chang YV, Wolk DA, Fernández-Seara MA, Detre JA. Whole-brain background-suppressed pCASL MRI with 1D-accelerated 3D RARE Stack-Of-Spirals readout. PLoS One 2017; 12:e0183762. [PMID: 28837640 PMCID: PMC5570334 DOI: 10.1371/journal.pone.0183762] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 08/10/2017] [Indexed: 11/19/2022] Open
Abstract
Arterial Spin Labeled (ASL) perfusion MRI enables non-invasive, quantitative measurements of tissue perfusion, and has a broad range of applications including brain functional imaging. However, ASL suffers from low signal-to-noise ratio (SNR), limiting image resolution. Acquisitions using 3D readouts are optimal for background-suppression of static signals, but can be SAR intensive and typically suffer from through-plane blurring. In this study, we investigated the use of accelerated 3D readouts to obtain whole-brain, high-SNR ASL perfusion maps and reduce SAR deposition. Parallel imaging was implemented along the partition-encoding direction in a pseudo-continuous ASL sequence with background-suppression and 3D RARE Stack-Of-Spirals readout, and its performance was evaluated in three small cohorts. First, both non-accelerated and two-fold accelerated single-shot versions of the sequence were evaluated in healthy volunteers during a motor-photic task, and the performance was compared in terms of temporal SNR, GM-WM contrast, and statistical significance of the detected activation. Secondly, single-shot 1D-accelerated imaging was compared to a two-shot accelerated version to assess benefits of SNR and spatial resolution for applications in which temporal resolution is not paramount. Third, the efficacy of this approach in clinical populations was assessed by applying the single-shot 1D-accelerated version to a larger cohort of elderly volunteers. Accelerated data demonstrated the ability to detect functional activation at the subject level, including cerebellar activity, without loss in the perfusion signal temporal stability and the statistical power of the activations. The use of acceleration also resulted in increased GM-WM contrast, likely due to reduced through-plane partial volume effects, that were further attenuated with the use of two-shot readouts. In a clinical cohort, image quality remained excellent, and expected effects of age and sex on cerebral blood flow could be detected. The sequence is freely available upon request for academic use and could benefit a broad range of cognitive and clinical neuroscience research.
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Affiliation(s)
- Marta Vidorreta
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ze Wang
- Department of Radiology, Temple University, Philadelphia, Pennsylvania, United States of America
- Center for Cognition and Brain Disorder, Hangzhou Normal University, Hangzhou, Zhejiang Province, China
| | - Yulin V. Chang
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - David A. Wolk
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - John A. Detre
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Dolui S, Vidorreta M, Wang Z, Nasrallah IM, Alavi A, Wolk DA, Detre JA. Comparison of PASL, PCASL, and background-suppressed 3D PCASL in mild cognitive impairment. Hum Brain Mapp 2017; 38:5260-5273. [PMID: 28737289 DOI: 10.1002/hbm.23732] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/30/2017] [Accepted: 07/09/2017] [Indexed: 12/21/2022] Open
Abstract
We compared three implementations of single-shot arterial spin labeled (ASL) perfusion magnetic resonance imaging: two-dimensional (2D) pulsed ASL (PASL), 2D pseudocontinuous ASL (PCASL), and background-suppressed (BS) 3D PCASL obtained in a cohort of patients with mild cognitive impairment (MCI) and elderly controls. Study subjects also underwent 18 F-fluorodeoxyglucose positron emission tomography (18 F-FDG PET). While BS 3D PCASL showed the lowest (P < 0.001) gray matter-white matter cerebral blood flow (CBF) contrast ratio, it provided the highest (P < 0.001) temporal signal-to-noise ratio. Mean relative CBF estimated using the PCASL methods in posterior cingulate cortex (PCC), precuneus, and hippocampus showed hypoperfusion in the MCI cohort compared to the controls consistent with hypometabolism measured by 18 F-FDG PET. BS 3D PCASL demonstrated the highest discrimination between controls and patients with effect size comparable to that seen with 18 F-FDG PET. 2D PASL did not demonstrate group differentiation with relative CBF in any ROI, whereas 2D PCASL demonstrated significant differences only in PCC and hippocampus. Mean global CBF values did not differ across methods and were highly correlated; however, the correlations were significantly higher (P < 0.001) when either the same labeling (PCASL) or the same acquisition strategy (2D) was used as compared to when both the labeling and readout methods differed. In addition, there were differences in regional distribution of CBF between the three modalities, which can be attributed to differences in sequence parameters. These results demonstrate the superiority of ASL with PCASL and BS 3D readout as a biomarker for regional brain function changes in MCI. Hum Brain Mapp 38:5260-5273, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Sudipto Dolui
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania.,Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Marta Vidorreta
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania.,Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ze Wang
- Department of Radiology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Ilya M Nasrallah
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Abass Alavi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David A Wolk
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John A Detre
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania.,Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, Pennsylvania
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37
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Lorenz K, Mildner T, Schlumm T, Möller HE. Characterization of pseudo-continuous arterial spin labeling: Simulations and experimental validation. Magn Reson Med 2017; 79:1638-1649. [DOI: 10.1002/mrm.26805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Kathrin Lorenz
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
- Faculty of Physics and Earth Sciences; University of Leipzig; Leipzig Germany
| | - Toralf Mildner
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
| | - Torsten Schlumm
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
| | - Harald E. Möller
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
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38
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Mao D, Li Y, Liu P, Peng SL, Pillai JJ, Lu H. Three-dimensional mapping of brain venous oxygenation using R2* oximetry. Magn Reson Med 2017; 79:1304-1313. [PMID: 28585238 DOI: 10.1002/mrm.26763] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/07/2017] [Accepted: 05/03/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE Cerebral venous oxygenation (Yv ) is an important biomarker for brain diseases. This study aims to develop an R2*-based MR oximetry that can measure cerebral Yv in 3D. METHODS This technique separates blood signal from tissue by velocity-encoding phase contrast and measures the R2* of pure blood by multi-gradient-echo acquisition. The blood R2* was converted to Yv using an R2*-versus-oxygenation (Y) calibration curve, which was obtained by in vitro bovine blood experiments. Reproducibility, sensitivity, validity, and resolution dependence of the technique were evaluated. RESULTS In vitro R2*-Y calibration plot revealed a strong dependence of blood R2* on oxygenation, with additional dependence on hematocrit. In vivo results demonstrated that the technique can provide a 3D venous oxygenation map that depicts both large sinuses and smaller cortical veins, with venous oxygenation ranging from 57 to 72%. Intrasession coefficient of variation of the measurement was 3.0%. The technique detected an average Yv increase of 10.8% as a result of hyperoxia, which was validated by global oxygenation measurement from T2 -Relaxation-Under-Spin-Tagging (TRUST) MRI. Two spatial resolutions, one with an isotropic voxel dimension and the other with a nonisotropic dimension, were tested for full brain coverage. CONCLUSIONS This study demonstrated the feasibility of 3D brain oxygenation mapping without using contrast agent. Magn Reson Med 79:1304-1313, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Deng Mao
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yang Li
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Peiying Liu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Shin-Lei Peng
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Jay J Pillai
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hanzhang Lu
- The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Ni WW, Christen T, Rosenberg J, Zun Z, Moseley ME, Zaharchuk G. Imaging of cerebrovascular reserve and oxygenation in Moyamoya disease. J Cereb Blood Flow Metab 2017; 37:1213-1222. [PMID: 27207169 PMCID: PMC5453445 DOI: 10.1177/0271678x16651088] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study aimed to determine whether measurements of cerebrovascular reserve and oxygenation, assessed with spin relaxation rate R2', yield similar information about pathology in pre-operative Moyamoya disease patients, and to assess whether R2' is a better measure of oxygenation than other proposed markers, such as R2* and R2. Twenty-five pre-operative Moyamoya disease patients were scanned at 3.0T with acetazolamide challenge. Cerebral blood flow mapping with multi-delay arterial spin labeling, and R2*, R2, and R2' mapping with Gradient-Echo Sampling of Free Induction Decay and Echo were performed. No baseline cerebral blood flow difference was found between angiographically abnormal and normal regions (49 ± 12 vs. 48 ± 11 mL/100 g/min, p = 0.44). However, baseline R2' differed between these regions (3.2 ± 0.7 vs. 2.9 ± 0.6 s-1, p < 0.001), indicating reduced oxygenation in abnormal regions. Cerebrovascular reserve was lower in angiographically abnormal regions (21 ± 38 vs. 41 ± 26%, p = 0.001). All regions showed trend toward significantly improved oxygenation post-acetazolamide. Regions with poorer cerebrovascular reserve had lower baseline oxygenation (Kendall's τ = -0.24, p = 0.003). A number of angiographically abnormal regions demonstrated preserved cerebrovascular reserve, likely due to the presence of collaterals. Finally, of the concurrently measured relaxation rates, R2' was superior for oxygenation assessment.
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Affiliation(s)
- Wendy W Ni
- 1 Department of Radiology, Stanford University, Stanford, CA, USA.,2 Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Thomas Christen
- 1 Department of Radiology, Stanford University, Stanford, CA, USA
| | | | - Zungho Zun
- 3 Division of Diagnostic Imaging and Radiology, Children's National Medical Center, Washington, DC, USA.,4 Department of Pediatrics, George Washington University, Washington, DC, USA
| | | | - Greg Zaharchuk
- 1 Department of Radiology, Stanford University, Stanford, CA, USA
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Grgac K, Li W, Huang A, Qin Q, van Zijl PCM. Transverse water relaxation in whole blood and erythrocytes at 3T, 7T, 9.4T, 11.7T and 16.4T; determination of intracellular hemoglobin and extracellular albumin relaxivities. Magn Reson Imaging 2016; 38:234-249. [PMID: 27993533 DOI: 10.1016/j.mri.2016.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 12/12/2016] [Indexed: 11/16/2022]
Abstract
Blood is a physiological substance with multiple water compartments, which contain water-binding proteins such as hemoglobin in erythrocytes and albumin in plasma. Knowing the water transverse (R2) relaxation rates from these different blood compartments is a prerequisite for quantifying the blood oxygenation level-dependent (BOLD) effect. Here, we report the Carr-Purcell-Meiboom-Gill (CPMG) based transverse (R2CPMG) relaxation rates of water in bovine blood samples circulated in a perfusion system at physiological temperature in order to mimic blood perfusion in humans. R2CPMG values of blood plasma, lysed packed erythrocytes, lysed plasma/erythrocyte mixtures, and whole blood at 3 T, 7 T, 9.4 T, 11.7 T and 16.4 T were measured as a function of hematocrit or hemoglobin concentration, oxygenation, and CPMG inter-echo spacing (τcp). R2CPMG in lysed cells showed a small τcp dependence, attributed to the water exchange rate between free and hemoglobin-bound water to be much faster than τcp. This was contrary to the tangential dependence in whole blood, where a much slower exchange between cells and blood plasma applies. Whole blood data were fitted as a function of τcp using a general tangential correlation time model applicable for exchange as well as diffusion contributions to R2CPMG, and the intercept R20blood at infinitely short τcp was determined. The R20blood values at different hematocrit and the R2CPMG values of lysed erythrocyte/plasma mixtures at different hemoglobin concentration were used to determine the relaxivity of hemoglobin inside the erythrocyte (r2Hb) and albumin (r2Alb) in plasma. The r2Hb values obtained from lysed erythrocytes and whole blood were comparable at full oxygenation. However, while r2Hb determined from lysed cells showed a linear dependence on oxygenation, this dependence became quadratic in whole blood. This possibly suggests an additional relaxation effect inside intact cells, perhaps due to hemoglobin proximity to the erythrocyte membrane. However, we cannot exclude that this is a consequence of the simple tangential model used to remove relaxation contributions from exchange and diffusion. The extensive data set presented should be useful for future theory development for the transverse relaxation of blood.
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Affiliation(s)
- Ksenija Grgac
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Wenbo Li
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Alan Huang
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Peter C M van Zijl
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
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41
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Chang YV, Vidorreta M, Wang Z, Detre JA. 3D-accelerated, stack-of-spirals acquisitions and reconstruction of arterial spin labeling MRI. Magn Reson Med 2016; 78:1405-1419. [PMID: 27813164 DOI: 10.1002/mrm.26549] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 11/07/2022]
Abstract
PURPOSE The goal of this study was to develop a 3D acceleration and reconstruction method to improve image quality and resolution of background-suppressed arterial spin-labeled perfusion MRI. METHODS Accelerated acquisition was implemented in all three k-space dimensions in a stack-of-spirals readout using variable density spirals and partition undersampling. A single 3D self-consistent parallel imaging (SPIRiT) kernel was calibrated and iteratively applied to reconstruct each imaging volume. Whole-brain (including cerebellum) perfusion imaging was obtained at 3-mm isotropic resolution (nominal) using single- and 2-shot acquisitions and at 2-mm isotropic resolution (nominal) using four-shot acquisitions, achieving effective acceleration factors between 5.5 and 6.6. The signal-to-noise (SNR) performance of 3D SPIRiT was evaluated. The temporal SNR (tSNR) of the cerebral blood flow (CBF) maps and the gray/white matter CBF ratios were quantified. RESULTS The readout of the arterial spin labeling (ASL) sequence was significantly shortened with acceleration. The CBF values were consistent between accelerated and fully sampled ASL. With shorter spiral interleaves and shorter echo trains, the accelerated images demonstrated reduced blurring and signal dropout in regions with high susceptibility gradients, resulting in improved image quality and increased gray/white matter CBF ratios. The shortened readout was accompanied by a corresponding decrease in tSNR. CONCLUSION The 3D acceleration and reconstruction allow a rapid whole-brain readout that improved the quality of ASL perfusion imaging. Magn Reson Med 78:1405-1419, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Yulin V Chang
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Marta Vidorreta
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ze Wang
- Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - John A Detre
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
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Perfusion Assessment Using Intravoxel Incoherent Motion-Based Analysis of Diffusion-Weighted Magnetic Resonance Imaging. Invest Radiol 2016; 51:520-8. [DOI: 10.1097/rli.0000000000000262] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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43
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Bush A, Borzage M, Detterich J, Kato RM, Meiselman HJ, Coates T, Wood JC. Empirical model of human blood transverse relaxation at 3 T improves MRI T 2 oximetry. Magn Reson Med 2016; 77:2364-2371. [PMID: 27385283 DOI: 10.1002/mrm.26311] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/28/2016] [Accepted: 05/25/2016] [Indexed: 11/06/2022]
Abstract
PURPOSE We sought a human blood T2 -oximetery calibration curve over the wide range of hematocrits commonly found in anemic patients applicable with T2 relaxation under spin tagging (TRUST). METHODS Blood was drawn from five healthy control subjects. Ninety-three in vitro blood transverse relaxation (T2b ) measurements were performed at 37°C over a broad range of hematocrits (10-55%) and oxygen saturations (14-100%) at 3 Tesla (T). In vivo TRUST was performed on 35 healthy African American control subjects and 11 patients with chronic anemia syndromes. RESULTS 1/T2 rose linearly with hematocrit (r2 = 0.96), for fully saturated blood. Upon desaturation, 1/T2 rose linearly with the square of the oxygen extraction, (1-Y)2 , and the slope was linearly proportional to hematocrit (r2 = 0.88). The resulting bilinear model between 1/T2 , (1-Y)2 , and hematocrit had a combined r2 of 0.96 and a coefficient of variation of 6.1%. Using the in vivo data, the bilinear model had significantly lower bias and variability than existing calibrations, particularly for low hematocrits. In vivo Bland Altman analysis demonstrated clinically relevant bias that was -6% (absolute saturation) for hematocrits near 30% and rose to + 6% for hematocrits near 45%. CONCLUSION This work introduces a robust bilinear calibration model that should be used for MRI oximetry. Magn Reson Med 77:2364-2371, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Adam Bush
- Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Matthew Borzage
- Division of Neonatology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - John Detterich
- Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Roberta M Kato
- Division of Pulmonary, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Herbert J Meiselman
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Thomas Coates
- Division of Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - John C Wood
- Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
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Petrovic A, Krauskopf A, Hassler E, Stollberger R, Scheurer E. Time related changes of T1, T2, and T2* of human blood in vitro. Forensic Sci Int 2016; 262:11-7. [DOI: 10.1016/j.forsciint.2016.02.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 02/10/2016] [Accepted: 02/18/2016] [Indexed: 11/15/2022]
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Hamilton JI, Jiang Y, Chen Y, Ma D, Lo WC, Griswold M, Seiberlich N. MR fingerprinting for rapid quantification of myocardial T 1 , T 2 , and proton spin density. Magn Reson Med 2016; 77:1446-1458. [PMID: 27038043 DOI: 10.1002/mrm.26216] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 12/27/2022]
Abstract
PURPOSE To introduce a two-dimensional MR fingerprinting (MRF) technique for quantification of T1 , T2 , and M0 in myocardium. METHODS An electrocardiograph-triggered MRF method is introduced for mapping myocardial T1 , T2 , and M0 during a single breath-hold in as short as four heartbeats. The pulse sequence uses variable flip angles, repetition times, inversion recovery times, and T2 preparation dephasing times. A dictionary of possible signal evolutions is simulated for each scan that incorporates the subject's unique variations in heart rate. Aspects of the sequence design were explored in simulations, and the accuracy and precision of cardiac MRF were assessed in a phantom study. In vivo imaging was performed at 3 Tesla in 11 volunteers to generate native parametric maps. RESULTS T1 and T2 measurements from the proposed cardiac MRF sequence correlated well with standard spin echo measurements in the phantom study (R2 > 0.99). A Bland-Altman analysis revealed good agreement for myocardial T1 measurements between MRF and MOLLI (bias 1 ms, 95% limits of agreement -72 to 72 ms) and T2 measurements between MRF and T2 -prepared balanced steady-state free precession (bias, -2.6 ms; 95% limits of agreement, -8.5 to 3.3 ms). CONCLUSION MRF can provide quantitative single slice T1 , T2 , and M0 maps in the heart within a single breath-hold. Magn Reson Med 77:1446-1458, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Jesse I Hamilton
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yun Jiang
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yong Chen
- Radiology, University Hospitals Case Medical Center, Cleveland, Ohio, USA
| | - Dan Ma
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei-Ching Lo
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mark Griswold
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.,Radiology, University Hospitals Case Medical Center, Cleveland, Ohio, USA
| | - Nicole Seiberlich
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.,Radiology, University Hospitals Case Medical Center, Cleveland, Ohio, USA
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Han PK, Ye JC, Kim EY, Choi SH, Park SH. Whole-brain perfusion imaging with balanced steady-state free precession arterial spin labeling. NMR IN BIOMEDICINE 2016; 29:264-274. [PMID: 26676386 DOI: 10.1002/nbm.3463] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 10/26/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
Recently, balanced steady-state free precession (bSSFP) readout has been proposed for arterial spin labeling (ASL) perfusion imaging to reduce susceptibility artifacts at a relatively high spatial resolution and signal-to-noise ratio (SNR). However, the main limitation of bSSFP-ASL is the low spatial coverage. In this work, methods to increase the spatial coverage of bSSFP-ASL are proposed for distortion-free, high-resolution, whole-brain perfusion imaging. Three strategies of (i) segmentation, (ii) compressed sensing (CS) and (iii) a hybrid approach combining the two methods were tested to increase the spatial coverage of pseudo-continuous ASL (pCASL) with three-dimensional bSSFP readout. The spatial coverage was increased by factors of two, four and six using each of the three approaches, whilst maintaining the same total scan time (5.3 min). The number of segments and/or CS acceleration rate (R) correspondingly increased to maintain the same bSSFP readout time (1.2 s). The segmentation approach allowed whole-brain perfusion imaging for pCASL-bSSFP with no penalty in SNR and/or total scan time. The CS approach increased the spatial coverage of pCASL-bSSFP whilst maintaining the temporal resolution, with minimal impact on the image quality. The hybrid approach provided compromised effects between the two methods. Balanced SSFP-based ASL allows the acquisition of perfusion images with wide spatial coverage, high spatial resolution and SNR, and reduced susceptibility artifacts, and thus may become a good choice for clinical and neurological studies. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Paul Kyu Han
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Jong Chul Ye
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Eung Yeop Kim
- Department of Radiology, Gachon University Gil Medical Center, Incheon, South Korea
| | - Seung Hong Choi
- Department of Radiology, Seoul National University College of Medicine, Seoul, South Korea
| | - Sung-Hong Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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47
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Lee CY, Thompson RT, Prato FS, Goldhawk DE, Gelman N. Investigating the Relationship between Transverse Relaxation Rate (R2) and Interecho Time in MagA-Expressing, Iron-Labeled Cells. Mol Imaging 2015; 14:551-60. [PMID: 26637544 DOI: 10.2310/7290.2015.00027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Reporter gene-based labeling of cells with iron is an emerging method of providing magnetic resonance imaging contrast for long-term cell tracking and monitoring cellular activities. This report investigates 9.4 T nuclear magnetic resonance properties of mammalian cells overexpressing MagA, a putative iron transport protein from magnetotactic bacteria. MagA-expressing MDA-MB-435 cells were cultured in the presence and absence of iron supplementation and compared to the untransfected control. The relationship between the transverse relaxation rate (R2) and interecho time was investigated using the Carr-Purcell-Meiboom-Gill sequence. This relationship was analyzed using a model based on water diffusion in weak magnetic field inhomogeneities (Jensen-Chandra model) as well as a fast-exchange model (Luz-Meiboom model). Increases in R2 with increasing interecho time were larger in the iron-supplemented, MagA-expressing cells compared to other cells. The dependence of R2 on interecho time in these iron-supplemented, MagA-expressing cells was better represented by the Jensen-Chandra model compared to the Luz-Meiboom model, whereas the Luz-Meiboom model performed better for the remaining cell types. Our findings provide an estimate of the distance scale of microscopic magnetic field variations in MagA-expressing cells, which is thought to be related to the size of iron-containing vesicles.
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Ma Y, Berman AJ, Pike GB. The effect of dissolved oxygen on the relaxation rates of blood plasma: Implications for hyperoxia calibrated BOLD. Magn Reson Med 2015; 76:1905-1911. [DOI: 10.1002/mrm.26069] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/05/2015] [Accepted: 11/02/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Yuhan Ma
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University; Montreal Quebec Canada
| | - Avery J.L. Berman
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University; Montreal Quebec Canada
- Department of Radiology and Hotchkiss Brain Institute; University of Calgary; Calgary Alberta Canada
| | - G. Bruce Pike
- Department of Radiology and Hotchkiss Brain Institute; University of Calgary; Calgary Alberta Canada
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Schmid S, Teeuwisse WM, Lu H, van Osch MJP. Time-efficient determination of spin compartments by time-encoded pCASL T2-relaxation-under-spin-tagging and its application in hemodynamic characterization of the cerebral border zones. Neuroimage 2015; 123:72-9. [PMID: 26297847 DOI: 10.1016/j.neuroimage.2015.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 07/31/2015] [Accepted: 08/11/2015] [Indexed: 11/19/2022] Open
Abstract
Information on water-transport across the blood-brain barrier can be determined from the T2 of the arterial spin labeling (ASL) signal. However, the current approach of using separate acquisitions of multiple inversion times is too time-consuming for clinical (research) applications. The aim of this study was to improve the time-efficiency of this method by combining it with time-encoded pseudo-continuous ASL (te-pCASL). Furthermore, the hemodynamic properties of the border zone regions in the brains of healthy, young volunteers were characterized as an example application. The use of te-pCASL instead of multi-TI pCASL significantly reduced the total scan duration, while providing a higher temporal resolution. A significantly lower cerebral blood flow (CBF) was found in the border zone regions compared with the central regions in both the posterior and the middle cerebral artery (MCA) flow territory. The arterial transit time (ATT) was almost two times longer in the border zone regions than in the central regions (p<0.05), with an average delay in ATT of 382ms in the posterior and 539ms in the MCA flow territory. When corrected for the ATT, the change in T2 over time was not significantly different for the border zones as compared to the central regions. In conclusion, te-pCASL-TRUST provided a time-efficient method to distinguish spin compartments based on their T2. The ATT in the border zone is significantly longer than in the central region. However, the exchange of the label from the arterial to the tissue compartment appears to be at a similar rate.
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Affiliation(s)
- Sophie Schmid
- C.J. Gorter Center for High Field MRI, Dept. of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Wouter M Teeuwisse
- C.J. Gorter Center for High Field MRI, Dept. of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University, Baltimore, United States.
| | - Matthias J P van Osch
- C.J. Gorter Center for High Field MRI, Dept. of Radiology, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
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50
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Comparison of velocity- and acceleration-selective arterial spin labeling with [15O]H2O positron emission tomography. J Cereb Blood Flow Metab 2015; 35:1296-303. [PMID: 25785831 PMCID: PMC4528003 DOI: 10.1038/jcbfm.2015.42] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 02/10/2015] [Accepted: 02/16/2015] [Indexed: 11/08/2022]
Abstract
In the last decade spatially nonselective arterial spin labeling (SNS-ASL) methods such as velocity-selective ASL (VS-ASL) and acceleration-selective ASL have been introduced, which label spins based on their flow velocity or acceleration rather than spatial localization. Since labeling also occurs within the imaging plane, these methods suffer less from transit delay effects than traditional ASL methods. However, there is a need for validation of these techniques. In this study, a comparison was made between these SNS-ASL techniques with [(15)O]H2O positron emission tomography (PET), which is regarded as gold standard to measure quantitatively cerebral blood flow (CBF) in humans. In addition, the question of whether these techniques suffered from sensitivity to arterial cerebral blood volume (aCBV), as opposed to producing pure CBF contrast, was investigated. The results show high voxelwise intracranial correlation (0.72 to 0.89) between the spatial distribution of the perfusion signal from the SNS-ASL methods and the PET CBF maps. A similar gray matter (GM) CBF was measured by dual VS-ASL compared with PET (46.7 ± 4.1 versus 47.1 ± 6.5 mL/100 g/min, respectively). Finally, only minor contribution of aCBV patterns in GM to all SNS-ASL methods was found compared with pseudo-continuous ASL. In conclusion, VS-ASL provides a similar quantitative CBF, and all SNS-ASL methods provide qualitatively similar CBF maps as [(15)O]H2O PET.
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