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Madsen SS, Lindberg U, Asghar S, Olsen KS, Møller K, Larsson HBW, Vestergaard MB. Reproducibility of cerebral blood flow, oxygen metabolism, and lactate and N-acetyl-aspartate concentrations measured using magnetic resonance imaging and spectroscopy. Front Physiol 2023; 14:1213352. [PMID: 37731542 PMCID: PMC10508186 DOI: 10.3389/fphys.2023.1213352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023] Open
Abstract
In humans, resting cerebral perfusion, oxygen consumption and energy metabolism demonstrate large intersubject variation regardless of methodology. Whether a similar large variation is also present longitudinally in individual subjects is much less studied, but knowing the time variance in reproducibility is important when designing and interpreting longitudinal follow-up studies examining brain physiology. Therefore, we examined the reproducibility of cerebral blood flow (CBF), global cerebral metabolic rate of oxygen (CMRO2), global arteriovenous oxygen saturation difference (A-V.O2), and cerebral lactate and N-acetyl-aspartate (NAA) concentrations measured using magnetic resonance imaging (MRI) and spectroscopy (MRS) techniques through repeated measurements at 6 h, 24 h, 7 days and several weeks after initial baseline measurements in young healthy adults (N = 26, 13 females, age range 18-35 years). Using this setup, we calculated the correlation, limit of agreement (LoA) and within-subject coefficient of variation (CoVWS) between baseline values and the subsequent repeated measurements to examine the longitudinal variation in individual cerebral physiology. CBF and CMRO2 correlated significantly between baseline and all subsequent measurements. The strength of the correlations (R2) and reproducibility metrics (LoA and CoVWS) demonstrated the best reproducibility for the within-day measurements and generally declined with longer time between measurements. Cerebral lactate and NAA concentrations also correlated significantly for all measurements, except between baseline and the 7-day measurement for lactate. Similar to CBF and CMRO2, lactate and NAA demonstrated the best reproducibility for within-day repeated measurements. The gradual decline in reproducibility over time should be considered when designing and interpreting studies on brain physiology, for example, in the evaluation of treatment efficacy.
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Affiliation(s)
- Signe Sloth Madsen
- Department of Anaesthesiology, Pain and Respiratory Support, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
| | - Sohail Asghar
- Anesthesiology and Intensive Care, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Karsten Skovgaard Olsen
- Department of Anaesthesiology, Pain and Respiratory Support, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Glostrup, Denmark
| | - Kirsten Møller
- Department of Neuroanaesthesiology, Neuroscience Centre, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mark Bitsch Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
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2
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Yang L, Cho J, Chen T, Gillen KM, Li J, Zhang Q, Guo L, Wang Y. Oxygen extraction fraction (OEF) assesses cerebral oxygen metabolism of deep gray matter in patients with pre-eclampsia. Eur Radiol 2022; 32:6058-6069. [PMID: 35348866 DOI: 10.1007/s00330-022-08713-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 01/19/2023]
Abstract
OBJECTIVES The objective of this study was to compare oxygen extraction fraction (OEF) values in the deep gray matter (GM) of pre-eclampsia (PE) patients, pregnant healthy controls (PHCs), and non-pregnant healthy controls (NPHCs) to explore their brain oxygen metabolism differences in GM. METHODS Forty-seven PE patients, forty NPHCs, and twenty-one PHCs were included. Brain OEF values were computed from quantitative susceptibility mapping (QSM) plus quantitative blood oxygen level-dependent magnitude (QSM + qBOLD = QQ)-based mapping. One-way ANOVA was used to compare mean OEF values in the three groups. The area under the curve of the mean OEF value in each region of interest was estimated using a receiver operating characteristic curve analysis. RESULTS We found that the mean OEF values in the thalamus, putamen, caudate nucleus, pallidum, and substantia nigra were significantly different in these three groups (F = 5.867, p = 0.004; F = 5.142, p = 0007; F = 6.158, p = 0.003; F = 6.319, p = 0.003; F = 5.491, p = 0.005). The mean OEF values for these 5 regions were higher in PE patients than in NPHCs and in PHCs (p < 0.05). The AUC of these ROIs ranged from 0.673 to 0.692 (p < 0.01) and cutoff values varied from 35.1 to 36.6%, indicating that the OEF values could discriminate patients with and without PE. Stepwise multivariate analysis revealed that the OEF values correlated with hematocrit in pregnant women (r = 0.353, p = 0.003). CONCLUSION OEF values in the brains of pregnant women can be measured in clinical practice using QQ-based OEF mapping for noninvasive assessment of hypertensive disorders. KEY POINTS • Pre-eclampsia is a hypertensive disorder associated with abnormalities in brain oxygen extraction. • Oxygen extraction fraction (OEF) is an indicator of brain tissue viability and function. QQ-based mapping of OEF is a new MRI technique that can noninvasively quantify brain oxygen metabolism. • OEF values in the brains of pregnant women can be measured for noninvasive assessment of hypertensive disorders in clinical practice.
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Affiliation(s)
- Linfeng Yang
- Jinan Maternity and Child Care Hospital, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, 2 Jian-guo Xiao Jing-san Road, Jinan, 250001, Shandong, China
| | - Junghun Cho
- Department of Radiology, Weill Cornell Medical College, New York, 407 East 61st Street, New York, NY, 10065, USA
| | - Tao Chen
- Jinan Maternity and Child Care Hospital, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, 2 Jian-guo Xiao Jing-san Road, Jinan, 250001, Shandong, China
| | - Kelly M Gillen
- Department of Radiology, Weill Cornell Medical College, New York, 407 East 61st Street, New York, NY, 10065, USA
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-an Road, Xicheng District, Beijing, 100050, China
| | - Qihao Zhang
- Department of Radiology, Weill Cornell Medical College, New York, 407 East 61st Street, New York, NY, 10065, USA
| | - Lingfei Guo
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jing-wu Road, Jinan, 250021, Shandong, China.
| | - Yi Wang
- Department of Radiology, Weill Cornell Medical College, New York, 407 East 61st Street, New York, NY, 10065, USA
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3
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Jiang D, Lu H. Cerebral oxygen extraction fraction MRI: Techniques and applications. Magn Reson Med 2022; 88:575-600. [PMID: 35510696 PMCID: PMC9233013 DOI: 10.1002/mrm.29272] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/20/2022] [Accepted: 03/29/2022] [Indexed: 12/20/2022]
Abstract
The human brain constitutes 2% of the body's total mass but uses 20% of the oxygen. The rate of the brain's oxygen utilization can be derived from a knowledge of cerebral blood flow and the oxygen extraction fraction (OEF). Therefore, OEF is a key physiological parameter of the brain's function and metabolism. OEF has been suggested to be a useful biomarker in a number of brain diseases. With recent advances in MRI techniques, several MRI-based methods have been developed to measure OEF in the human brain. These MRI OEF techniques are based on the T2 of blood, the blood signal phase, the magnetic susceptibility of blood-containing voxels, the effect of deoxyhemoglobin on signal behavior in extravascular tissue, and the calibration of the BOLD signal using gas inhalation. Compared to 15 O PET, which is considered the "gold standard" for OEF measurement, MRI-based techniques are non-invasive, radiation-free, and are more widely available. This article provides a review of these emerging MRI-based OEF techniques. We first briefly introduce the role of OEF in brain oxygen homeostasis. We then review the methodological aspects of different categories of MRI OEF techniques, including their signal mechanisms, acquisition methods, and data analyses. The strengths and limitations of the techniques are discussed. Finally, we review key applications of these techniques in physiological and pathological conditions.
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Affiliation(s)
- Dengrong Jiang
- 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.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
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4
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Zhao MY, Woodward A, Fan AP, Chen KT, Yu Y, Chen DY, Moseley ME, Zaharchuk G. Reproducibility of cerebrovascular reactivity measurements: A systematic review of neuroimaging techniques . J Cereb Blood Flow Metab 2022; 42:700-717. [PMID: 34806918 PMCID: PMC9254040 DOI: 10.1177/0271678x211056702] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cerebrovascular reactivity (CVR), the capacity of the brain to increase cerebral blood flow (CBF) to meet changes in physiological demand, is an important biomarker to evaluate brain health. Typically, this brain "stress test" is performed by using a medical imaging modality to measure the CBF change between two states: at baseline and after vasodilation. However, since there are many imaging modalities and many ways to augment CBF, a wide range of CVR values have been reported. An understanding of CVR reproducibility is critical to determine the most reliable methods to measure CVR as a clinical biomarker. This review focuses on CVR reproducibility studies using neuroimaging techniques in 32 articles comprising 427 total subjects. The literature search was performed in PubMed, Embase, and Scopus. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We identified 5 factors of the experimental subjects (such as sex, blood characteristics, and smoking) and 9 factors of the measuring technique (such as the imaging modality, the type of the vasodilator, and the quantification method) that have strong effects on CVR reproducibility. Based on this review, we recommend several best practices to improve the reproducibility of CVR quantification in neuroimaging studies.
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Affiliation(s)
- Moss Y Zhao
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Amanda Woodward
- Lane Medical Library, Stanford University, Stanford, CA, USA
| | - Audrey P Fan
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA.,Department of Neurology, University of California Davis, Davis, CA, USA
| | - Kevin T Chen
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Yannan Yu
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - David Y Chen
- Department of Medical Imaging, Taipei Medical University - Shuan-Ho Hospital, New Taipei City.,Department of Radiology, School of Medicine, Taipei Medical University, Taipei *Research materials supporting this publication can be accessed at https://doi.org/10.25740/hd852bg4538
| | | | - Greg Zaharchuk
- Department of Radiology, Stanford University, Stanford, CA, USA
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5
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Champagne AA, Coverdale NS, Allen MD, Tremblay JC, MacPherson REK, Pyke KE, Olver TD, Cook DJ. The physiological basis underlying functional connectivity differences in older adults: A multi-modal analysis of resting-state fMRI. Brain Imaging Behav 2022; 16:1575-1591. [PMID: 35092574 DOI: 10.1007/s11682-021-00570-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 09/27/2021] [Indexed: 11/02/2022]
Abstract
The purpose of this study was to determine if differences in functional connectivity strength (FCS) with age were confounded by vascular parameters including resting cerebral blood flow (CBF0), cerebrovascular reactivity (CVR), and BOLD-CBF coupling. Neuroimaging data were collected from 13 younger adults (24 ± 2 years) and 14 older adults (71 ± 4 years). A dual-echo resting state pseudo-continuous arterial spin labeling sequence was performed, as well as a BOLD breath-hold protocol. A group independent component analysis was used to identify networks, which were amalgamated into a region of interest (ROI). Within the ROI, FC strength (FCS) was computed for all voxels and compared across the groups. CBF0, CVR and BOLD-CBF coupling were examined within voxels where FCS was different between young and older adults. FCS was greater in old compared to young (P = 0.001). When the effect of CBF0, CVR and BOLD-CBF coupling on FCS was examined, BOLD-CBF coupling had a significant effect (P = 0.003) and group differences in FCS were not present once all vascular parameters were considered in the statistical model (P = 0.07). These findings indicate that future studies of FCS should consider vascular physiological markers in order to improve our understanding of aging processes on brain connectivity.
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Affiliation(s)
- Allen A Champagne
- Centre for Neuroscience Studies, Queen's University, Room 260, Kingston, ON, K7L 3N6, Canada
| | - Nicole S Coverdale
- Centre for Neuroscience Studies, Queen's University, Room 260, Kingston, ON, K7L 3N6, Canada
| | - Matti D Allen
- Department of Physical Medicine and Rehabilitation, Queen's University, Kingston, ON, Canada.,School of Kinesiology and Health Studies, Cardiovascular Stress Response Laboratory, Queen's University, Kingston, ON, K7L 3N6, Canada.,Department of Physical Medicine and Rehabilitation, Providence Care Hospital, 752 King St., Ontario, West Kingston, Canada
| | - Joshua C Tremblay
- School of Kinesiology and Health Studies, Cardiovascular Stress Response Laboratory, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Rebecca E K MacPherson
- Department of Health Sciences, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St Catharines, ON, L2S 3A1, Canada
| | - Kyra E Pyke
- School of Kinesiology and Health Studies, Cardiovascular Stress Response Laboratory, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - T Dylan Olver
- Biomedical Sciences, Western College of Veterinarian Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Douglas J Cook
- Centre for Neuroscience Studies, Queen's University, Room 260, Kingston, ON, K7L 3N6, Canada. .,Department of Surgery, Queen's University, Room 232, 18 Stuart St, Kingston, ON, K7L 3N6, Canada.
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6
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Cho J, Lee J, An H, Goyal MS, Su Y, Wang Y. Cerebral oxygen extraction fraction (OEF): Comparison of challenge-free gradient echo QSM+qBOLD (QQ) with 15O PET in healthy adults. J Cereb Blood Flow Metab 2021; 41:1658-1668. [PMID: 33243071 PMCID: PMC8221765 DOI: 10.1177/0271678x20973951] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We aimed to validate oxygen extraction fraction (OEF) estimations by quantitative susceptibility mapping plus quantitative blood oxygen-level dependence (QSM+qBOLD, or QQ) using 15O-PET. In ten healthy adult brains, PET and MRI were acquired simultaneously on a PET/MR scanner. PET was acquired using C[15O], O[15O], and H2[15O]. Image-derived arterial input functions and standard models of oxygen metabolism provided quantification of PET. MRI included T1-weighted imaging, time-of-flight angiography, and multi-echo gradient-echo imaging that was processed for QQ. Region of interest (ROI) analyses compared PET OEF and QQ OEF. In ROI analyses, the averaged OEF differences between PET and QQ were generally small and statistically insignificant. For whole brains, the average and standard deviation of OEF was 32.8 ± 6.7% for PET; OEF was 34.2 ± 2.6% for QQ. Bland-Altman plots quantified agreement between PET OEF and QQ OEF. The interval between the 95% limits of agreement was 16.9 ± 4.0% for whole brains. Our validation study suggests that respiratory challenge-free QQ-OEF mapping may be useful for non-invasive clinical assessment of regional OEF impairment.
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Affiliation(s)
- Junghun Cho
- Department of Radiology, Weill Cornell Medical College, New York, USA
| | - John Lee
- Mallinkckrodt Institute of Radiology, Washington University School of Medicine, St Louis, USA
| | - Hongyu An
- Mallinkckrodt Institute of Radiology, Washington University School of Medicine, St Louis, USA
| | - Manu S Goyal
- Mallinkckrodt Institute of Radiology, Washington University School of Medicine, St Louis, USA
| | - Yi Su
- Computational Image Analysis, Banner Alzheimer's Institute, Phoenix, USA
| | - Yi Wang
- Department of Radiology, Weill Cornell Medical College, New York, USA.,Department of Biomedical Engineering, Cornell University, Ithaca, USA
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7
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Champagne AA, Coverdale NS, Fernandez-Ruiz J, Mark CI, Cook DJ. Compromised resting cerebral metabolism after sport-related concussion: A calibrated MRI study. Brain Imaging Behav 2021; 15:133-146. [PMID: 32307673 DOI: 10.1007/s11682-019-00240-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Altered resting cerebral blood flow (CBF0) in the acute phase post-concussion may contribute to neurobehavioral deficiencies, often reported weeks after the injury. However, in addition to changes in CBF0, little is known about other physiological mechanisms that may be disturbed within the cerebrovasculature. The aim of this study was to assess whether changes in baseline perfusion following sport-related concussion (SRC) were co-localized with changes in cerebral metabolic demand. Forty-two subjects (15 SRC patients 8.0 ± 4.6 days post-injury and 27 age-matched healthy control athletes) were studied cross-sectionally. CBF0, cerebrovascular reactivity (CVR), resting oxygen extraction (OEF0) and cerebral metabolic rate of oxygen consumption (CMRO2|0) were measured using a combination of hypercapnic and hyperoxic breathing protocols, and the biophysical model developed in calibrated MRI. Blood oxygenation level dependent and perfusion data were acquired simultaneously using a dual-echo arterial spin labelling sequence. SRC patients showed significant decreases in CBF0 spread across the grey-matter (P < 0.05, corrected), and these differences were also confounded by the effects of baseline end-tidal CO2 (P < 0.0001). Lower perfusion was co-localized with reductions in regional CMRO2|0 (P = 0.006) post-SRC, despite finding no group-differences in OEF0 (P = 0.800). Higher CVR within voxels showing differences in CBF was also observed in the SRC group (P = 0.001), compared to controls. Reductions in metabolic demand despite no significant changes in OEF0 suggests that hypoperfusion post-SRC may reflect compromised metabolic function after the injury. These results provide novel insight about the possible pathophysiological mechanisms underlying concussion that may affect the clinical recovery of athletes after sport-related head injuries.
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Affiliation(s)
- Allen A Champagne
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Nicole S Coverdale
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Juan Fernandez-Ruiz
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Clarisse I Mark
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Douglas J Cook
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada.
- Department of Surgery, Queen's University, Room 232, 18 Stuart St., Kingston, ON, K7L 3N6, Canada.
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8
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Hubbard NA, Turner MP, Sitek KR, West KL, Kaczmarzyk JR, Himes L, Thomas BP, Lu H, Rypma B. Resting cerebral oxygen metabolism exhibits archetypal network features. Hum Brain Mapp 2021; 42:1952-1968. [PMID: 33544446 PMCID: PMC8046048 DOI: 10.1002/hbm.25352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/04/2020] [Accepted: 01/12/2021] [Indexed: 12/23/2022] Open
Abstract
Standard magnetic resonance imaging approaches offer high‐resolution but indirect measures of neural activity, limiting understanding of the physiological processes associated with imaging findings. Here, we used calibrated functional magnetic resonance imaging during the resting state to recover low‐frequency fluctuations of the cerebral metabolic rate of oxygen (CMRO2). We tested whether functional connections derived from these fluctuations exhibited organization properties similar to those established by previous standard functional and anatomical connectivity studies. Seventeen participants underwent 20 min of resting imaging during dual‐echo, pseudocontinuous arterial spin labeling, and blood‐oxygen‐level dependent (BOLD) signal acquisition. Participants also underwent a 10 min normocapnic and hypercapnic procedure. Brain‐wide, CMRO2 low‐frequency fluctuations were subjected to graph‐based and voxel‐wise functional connectivity analyses. Results demonstrated that connections derived from resting CMRO2 fluctuations exhibited complex, small‐world topological properties (i.e., high integration and segregation, cost efficiency) consistent with those observed in previous studies using functional and anatomical connectivity approaches. Voxel‐wise CMRO2 connectivity also exhibited spatial patterns consistent with four targeted resting‐state subnetworks: two association (i.e., frontoparietal and default mode) and two perceptual (i.e., auditory and occipital‐visual). These are the first findings to support the use of calibration‐derived CMRO2 low‐frequency fluctuations for detecting brain‐wide organizational properties typical of healthy participants. We discuss interpretations, advantages, and challenges in using calibration‐derived oxygen metabolism signals for examining the intrinsic organization of the human brain.
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Affiliation(s)
- Nicholas A Hubbard
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Center for Brain, Biology, and Behavior, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Kevin R Sitek
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Division of Medical Sciences, Harvard Medical School, Boston, Massachusetts, USA
| | - Kathryn L West
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Jakub R Kaczmarzyk
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lyndahl Himes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Binu P Thomas
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA.,Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hanzhang Lu
- Department of Radiology, John's Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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9
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West KL, Sivakolundu DK, Zuppichini MD, Turner MP, Spence JS, Lu H, Okuda DT, Rypma B. Altered task-induced cerebral blood flow and oxygen metabolism underlies motor impairment in multiple sclerosis. J Cereb Blood Flow Metab 2021; 41:182-193. [PMID: 32126873 PMCID: PMC7747162 DOI: 10.1177/0271678x20908356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/29/2019] [Accepted: 12/04/2019] [Indexed: 02/01/2023]
Abstract
The neural mechanisms underlying motor impairment in multiple sclerosis (MS) remain unknown. Motor cortex dysfunction is implicated in blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) studies, but the role of neural-vascular coupling underlying BOLD changes remains unknown. We sought to independently measure the physiologic factors (i.e., cerebral blood flow (ΔCBF), cerebral metabolic rate of oxygen (ΔCMRO2), and flow-metabolism coupling (ΔCBF/ΔCMRO2), utilizing dual-echo calibrated fMRI (cfMRI) during a bilateral finger-tapping task. We utilized cfMRI to measure physiologic responses in 17 healthy volunteers and 32 MS patients (MSP) with and without motor impairment during a thumb-button-press task in thumb-related (task-central) and surrounding primary motor cortex (task-surround) regions of interest (ROIs). We observed significant ΔCBF and ΔCMRO2 increases in all MSP compared to healthy volunteers in the task-central ROI and increased flow-metabolism coupling (ΔCBF/ΔCMRO2) in the MSP without motor impairment. In the task-surround ROI, we observed decreases in ΔCBF and ΔCMRO2 in MSP with motor impairment. Additionally, ΔCBF and ΔCMRO2 responses in the task-surround ROI were associated with motor function and white matter damage in MSP. These results suggest an important role for task-surround recruitment in the primary motor cortex to maintain motor dexterity and its dependence on intact white matter microstructure and neural-vascular coupling.
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Affiliation(s)
- Kathryn L West
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Dinesh K Sivakolundu
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Mark D Zuppichini
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Jeffrey S Spence
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Darin T Okuda
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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10
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Champagne AA, Coverdale NS, Germuska M, Bhogal AA, Cook DJ. Changes in volumetric and metabolic parameters relate to differences in exposure to sub-concussive head impacts. J Cereb Blood Flow Metab 2020; 40:1453-1467. [PMID: 31307284 PMCID: PMC7308522 DOI: 10.1177/0271678x19862861] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 06/11/2019] [Indexed: 01/15/2023]
Abstract
Structural and calibrated magnetic resonance imaging data were acquired on 44 collegiate football players prior to the season (PRE), following the first four weeks in-season (PTC) and one month after the last game (POST). Exposure data collected from g-Force accelerometers mounted to the helmet of each player were used to split participants into HIGH (N = 22) and LOW (N = 22) exposure groups, based on the frequency of impacts sustained by each athlete. Significant decreases in grey-matter volume specific to the HIGH group were documented at POST (P = 0.009), compared to baseline. Changes in resting cerebral blood flow (CBF0), corrected for partial volume effects, were observed within the HIGH group, throughout the season (P < 0.0001), suggesting that alterations in perfusion may follow exposure to sub-concussive collisions. Co-localized significant increases in cerebral metabolic rate of oxygen consumption (CMRO2|0) mid-season were also documented in the HIGH group, with respect to both PRE- and POST values. No physiological changes were observed in the LOW group. Therefore, cerebral metabolic demand may be elevated in players with greater exposure to head impacts. These results provide novel insight into the effects of sub-concussive collisions on brain structure and cerebrovascular physiology and emphasize the importance of multi-modal imaging for a complete characterization of cerebral health.
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Affiliation(s)
- Allen A Champagne
- Centre for Neuroscience Studies, Queen’s
University, Kingston, ON, Canada
| | - Nicole S Coverdale
- Centre for Neuroscience Studies, Queen’s
University, Kingston, ON, Canada
| | - Mike Germuska
- Cardiff University Brain Research
Imaging Center, Cardiff University, Cardiff, UK
| | - Alex A Bhogal
- Department of Radiology, University
Medical Center Utrecht, Utrecht, The Netherlands
| | - Douglas J Cook
- Centre for Neuroscience Studies, Queen’s
University, Kingston, ON, Canada
- Department of Surgery, Queen’s
University, Kingston, ON, Canada
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11
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Englund EK, Fernández-Seara MA, Rodríguez-Soto AE, Lee H, Rodgers ZB, Vidorreta M, Detre JA, Wehrli FW. Calibrated fMRI for dynamic mapping of CMRO 2 responses using MR-based measurements of whole-brain venous oxygen saturation. J Cereb Blood Flow Metab 2020; 40:1501-1516. [PMID: 31394960 PMCID: PMC7308517 DOI: 10.1177/0271678x19867276] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Functional MRI (fMRI) can identify active foci in response to stimuli through BOLD signal fluctuations, which represent a complex interplay between blood flow and cerebral metabolic rate of oxygen (CMRO2) changes. Calibrated fMRI can disentangle the underlying contributions, allowing quantification of the CMRO2 response. Here, whole-brain venous oxygen saturation (Yv) was computed alongside ASL-measured CBF and BOLD-weighted data to derive the calibration constant, M, using the proposed Yv-based calibration. Data were collected from 10 subjects at 3T with a three-part interleaved sequence comprising background-suppressed 3D-pCASL, 2D BOLD-weighted, and single-slice dual-echo GRE (to measure Yv via susceptometry-based oximetry) acquisitions while subjects breathed normocapnic/normoxic, hyperoxic, and hypercapnic gases, and during a motor task. M was computed via Yv-based calibration from both hypercapnia and hyperoxia stimulus data, and results were compared to conventional hypercapnia or hyperoxia calibration methods. Mean M in gray matter did not significantly differ between calibration methods, ranging from 8.5 ± 2.8% (conventional hyperoxia calibration) to 11.7 ± 4.5% (Yv-based calibration in response to hyperoxia), with hypercapnia-based M values between (p = 0.56). Relative CMRO2 changes from finger tapping were computed from each M map. CMRO2 increased by ∼20% in the motor cortex, and good agreement was observed between the conventional and proposed calibration methods.
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Affiliation(s)
- Erin K Englund
- Laboratory for Structural, Physiologic and Functional Imaging (LSPFI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Ana E Rodríguez-Soto
- Laboratory for Structural, Physiologic and Functional Imaging (LSPFI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hyunyeol Lee
- Laboratory for Structural, Physiologic and Functional Imaging (LSPFI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Zachary B Rodgers
- Laboratory for Structural, Physiologic and Functional Imaging (LSPFI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.,Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Marta Vidorreta
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.,Siemens Healthineers, Madrid, Spain
| | - John A Detre
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Felix W Wehrli
- Laboratory for Structural, Physiologic and Functional Imaging (LSPFI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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12
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Zohdi H, Scholkmann F, Wolf U. Frontal cerebral oxygenation asymmetry: intersubject variability and dependence on systemic physiology, season, and time of day. NEUROPHOTONICS 2020; 7:025006. [PMID: 32607390 PMCID: PMC7310879 DOI: 10.1117/1.nph.7.2.025006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/08/2020] [Indexed: 05/04/2023]
Abstract
Significance: Our study reveals that frontal cerebral oxygenation asymmetry (FCOA), i.e. a difference in the oxygenation between the right and left prefrontal cortex (PFC), is a real phenomenon in healthy human subjects at rest. Aim: To investigate FCOA, we performed a study with 134 healthy right-handed subjects with the systemic physiology augmented functional near infrared spectroscopy (SPA-fNIRS) approach. Approach: Subjects were measured 2 to 4 times on different days resulting in an unprecedented number of 518 single measurements of the absolute values of tissue oxygen saturation (StO 2 ) and total hemoglobin concentration ([tHb]) of the right and left PFC. Measurements were performed with frequency-domain functional near-infrared spectroscopy. In addition, the cardiorespiratory parameters were measured simultaneously. Results: We found that (i) subjects showed an FCOA (higherStO 2 on the right PFC), but not for tHb; (ii) intrasubject variability was excellent for bothStO 2 and tHb, and fair for FCOA; (iii) StO 2 correlated significantly with bloodCO 2 concentration, [tHb] with heart rate, respiration rate (RR), and the pulse-respiration quotient (PRQ), and FCOA with RR and PRQ; (iv) FCOA andStO 2 were dependent on season and time of day, respectively; (v) FCOA was negatively correlated with the room temperature; and (vi) StO 2 and tHb were not correlated with the subjects mood but with their chronotype, whereas FCOA was not dependent on the chronotype. Conclusion: Our study demonstrates that FCOA is real, and it provides unique insights into this remarkable phenomenon.
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Affiliation(s)
- Hamoon Zohdi
- University of Bern, Institute of Complementary and Integrative Medicine, Bern, Switzerland
| | - Felix Scholkmann
- University of Bern, Institute of Complementary and Integrative Medicine, Bern, Switzerland
- University of Zurich, University Hospital Zurich, Biomedical Optics Research Laboratory, Department of Neonatology, Zurich, Switzerland
| | - Ursula Wolf
- University of Bern, Institute of Complementary and Integrative Medicine, Bern, Switzerland
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13
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Champagne AA, Coverdale NS, Ross A, Chen Y, Murray CI, Dubowitz D, Cook DJ. Multi-modal normalization of resting-state using local physiology reduces changes in functional connectivity patterns observed in mTBI patients. Neuroimage Clin 2020; 26:102204. [PMID: 32058317 PMCID: PMC7013121 DOI: 10.1016/j.nicl.2020.102204] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/02/2020] [Accepted: 02/03/2020] [Indexed: 12/25/2022]
Abstract
Blood oxygenation level dependent (BOLD) resting-state functional magnetic resonance imaging (rs-fMRI) may serve as a sensitive marker to identify possible changes in the architecture of large-scale networks following mild traumatic brain injury (mTBI). Differences in functional connectivity (FC) measurements derived from BOLD rs-fMRI may however be confounded by changes in local cerebrovascular physiology and neurovascular coupling mechanisms, without changes in the underlying neuronally driven connectivity of networks. In this study, multi-modal neuroimaging data including BOLD rs-fMRI, baseline cerebral blood flow (CBF0) and cerebrovascular reactivity (CVR; acquired using a hypercapnic gas breathing challenge) were collected in 23 subjects with reported mTBI (14.6±14.9 months post-injury) and 27 age-matched healthy controls. Despite no group differences in CVR within the networks of interest (P > 0.05, corrected), significantly higher CBF0 was documented in the mTBI subjects (P < 0.05, corrected), relative to the controls. A normalization method designed to account for differences in CBF0 post-mTBI was introduced to evaluate the effects of such an approach on reported group differences in network connectivity. Inclusion of regional perfusion measurements in the computation of correlation coefficients within and across large-scale networks narrowed the differences in FC between the groups, suggesting that this approach may elucidate unique changes in connectivity post-mTBI while accounting for shared variance with CBF0. Altogether, our results provide a strong paradigm supporting the need to account for changes in physiological modulators of BOLD in order to expand our understanding of the effects of brain injury on large-scale FC of cortical networks.
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Affiliation(s)
- Allen A Champagne
- Centre for Neuroscience Studies, Room 260, Queen's University, Kingston ON K7L 3N6 Canada.
| | - Nicole S Coverdale
- Centre for Neuroscience Studies, Room 260, Queen's University, Kingston ON K7L 3N6 Canada.
| | - Andrew Ross
- Performance Phenomics, 180 John St., Toronto ON M5T 1 × 5 Canada.
| | - Yining Chen
- Centre for Neuroscience Studies, Room 260, Queen's University, Kingston ON K7L 3N6 Canada.
| | | | - David Dubowitz
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand.
| | - Douglas J Cook
- Centre for Neuroscience Studies, Room 260, Queen's University, Kingston ON K7L 3N6 Canada; Department of Surgery, Queen's University, Kingston, ON, Canada.
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14
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The association between BOLD-based cerebrovascular reactivity (CVR) and end-tidal CO 2 in healthy subjects. Neuroimage 2019; 207:116365. [PMID: 31734432 PMCID: PMC8080082 DOI: 10.1016/j.neuroimage.2019.116365] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/25/2019] [Accepted: 11/13/2019] [Indexed: 01/22/2023] Open
Abstract
Cerebrovascular reactivity (CVR) mapping using CO2-inhalation can provide important insight into vascular health. At present, blood-oxygenation-level-dependent (BOLD) MRI acquisition is the most commonly used CVR method due to its high sensitivity, high spatial resolution, and relatively straightforward processing. However, large variations in CVR across subjects and across different sessions of the same subject are often observed, which can cloud the ability of this promising measure in detecting diseases or monitoring treatment responses. The present work aims to identify the physiological components underlying the observed variability in CVR data. When studying the association between CVR value and the subject’s CO2 levels in a total of N = 253 healthy participants, we found that CVR was lower in individuals with a higher basal end-tidal CO2, EtCO2 (slope = −0.0036 ± 0.0008%/mmHg2, p < 0.001), or with a greater EtCO2 change (ΔEtCO2) with hypercapnic condition (slope = −0.0072 ± 0.0018%/mmHg2, p < 0.001). In a within-subject setting, when studying the CVR difference between two repeated scans (with repositioning) in relation to the corresponding differences in basal EtCO2 and ΔEtCO2 (n = 11), it was found that CVR values were lower if the basal EtCO2 or ΔEtCO2 during that particular scan session was greater. The present work suggests that basal physiological state and the level of hypercapnic stimulus intensity should be considered in application studies of CVR in order to reduce inter-subject and intra-subject variations in the data. Potential approaches to use these findings to reduce noise and augment sensitivity are proposed.
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15
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Ma Y, Sun H, Cho J, Mazerolle EL, Wang Y, Pike GB. Cerebral OEF quantification: A comparison study between quantitative susceptibility mapping and dual‐gas calibrated BOLD imaging. Magn Reson Med 2019; 83:68-82. [DOI: 10.1002/mrm.27907] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/23/2019] [Accepted: 06/25/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Yuhan Ma
- McConnell Brain Imaging Centre Montreal Neurological Institute, McGill University Montreal Quebec Canada
| | - Hongfu Sun
- Department of Radiology and Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
- School of Information Technology and Electrical Engineering University of Queensland Brisbane Australia
| | - Junghun Cho
- Department of Biomedical Engineering Cornell University Ithaca New York
| | - Erin L. Mazerolle
- Department of Radiology and Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
| | - Yi Wang
- Department of Biomedical Engineering Cornell University Ithaca New York
- Department of Radiology Weill Cornell Medical College New York New York
| | - G. Bruce Pike
- 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
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16
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BOLD signal physiology: Models and applications. Neuroimage 2019; 187:116-127. [DOI: 10.1016/j.neuroimage.2018.03.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/14/2018] [Accepted: 03/08/2018] [Indexed: 12/14/2022] Open
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17
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Merola A, Germuska MA, Murphy K, Wise RG. Assessing the repeatability of absolute CMRO 2, OEF and haemodynamic measurements from calibrated fMRI. Neuroimage 2018; 173:113-126. [PMID: 29454105 PMCID: PMC6503182 DOI: 10.1016/j.neuroimage.2018.02.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/12/2018] [Accepted: 02/12/2018] [Indexed: 12/27/2022] Open
Abstract
As energy metabolism in the brain is largely oxidative, the measurement of cerebral metabolic rate of oxygen consumption (CMRO2) is a desirable biomarker for quantifying brain activity and tissue viability. Currently, PET techniques based on oxygen isotopes are the gold standard for obtaining whole brain CMRO2 maps. Among MRI techniques that have been developed as an alternative are dual calibrated fMRI (dcFMRI) methods, which exploit simultaneous measurements of BOLD and ASL signals during a hypercapnic-hyperoxic experiment to modulate brain blood flow and oxygenation. In this study we quantified the repeatability of a dcFMRI approach developed in our lab, evaluating its limits and informing its application in studies aimed at characterising the metabolic state of human brain tissue over time. Our analysis focussed on the estimates of oxygen extraction fraction (OEF), cerebral blood flow (CBF), CBF-related cerebrovascular reactivity (CVR) and CMRO2 based on a forward model that describes analytically the acquired dual echo GRE signal. Indices of within- and between-session repeatability are calculated from two different datasets both at a bulk grey matter and at a voxel-wise resolution and finally compared with similar indices obtained from previous MRI and PET measurements. Within- and between-session values of intra-subject coefficient of variation (CVintra) calculated from bulk grey matter estimates 6.7 ± 6.6% (mean ± std.) and 10.5 ± 9.7% for OEF, 6.9 ± 6% and 5.5 ± 4.7% for CBF, 12 ± 9.7% and 12.3 ± 10% for CMRO2. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) maps showed the spatial distribution of the repeatability metrics, informing on the feasibility limits of the method. In conclusion, results show an overall consistency of the estimated physiological parameters with literature reports and a satisfactory level of repeatability considering the higher spatial sensitivity compared to other MRI methods, with varied performance depending on the specific parameter under analysis, on the spatial resolution considered and on the study design.
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Affiliation(s)
- Alberto Merola
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, UK; Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, DE, Germany
| | - Michael A Germuska
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, UK
| | - Kevin Murphy
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Physics and Astronomy, Cardiff University, UK
| | - Richard G Wise
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, UK.
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18
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Germuska M, Wise RG. Calibrated fMRI for mapping absolute CMRO 2: Practicalities and prospects. Neuroimage 2018; 187:145-153. [PMID: 29605580 DOI: 10.1016/j.neuroimage.2018.03.068] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/14/2018] [Accepted: 03/28/2018] [Indexed: 01/21/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) is an essential workhorse of modern neuroscience, providing valuable insight into the functional organisation of the brain. The physiological mechanisms underlying the blood oxygenation level dependent (BOLD) effect are complex and preclude a straightforward interpretation of the signal. However, by employing appropriate calibration of the BOLD signal, quantitative measurements can be made of important physiological parameters including the absolute rate of cerebral metabolic oxygen consumption or oxygen metabolism (CMRO2) and oxygen extraction (OEF). The ability to map such fundamental parameters has the potential to greatly expand the utility of fMRI and to broaden its scope of application in clinical research and clinical practice. In this review article we discuss some of the practical issues related to the calibrated-fMRI approach to the measurement of CMRO2. We give an overview of the necessary precautions to ensure high quality data acquisition, and explore some of the pitfalls and challenges that must be considered as it is applied and interpreted in a widening array of diseases and research questions.
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Affiliation(s)
- M Germuska
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ, Cardiff, UK
| | - R G Wise
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ, Cardiff, UK.
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19
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Liu P, De Vis JB, Lu H. Cerebrovascular reactivity (CVR) MRI with CO2 challenge: A technical review. Neuroimage 2018; 187:104-115. [PMID: 29574034 DOI: 10.1016/j.neuroimage.2018.03.047] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/06/2018] [Accepted: 03/19/2018] [Indexed: 11/16/2022] Open
Abstract
Cerebrovascular reactivity (CVR) is an indicator of cerebrovascular reserve and provides important information about vascular health in a range of brain conditions and diseases. Unlike steady-state vascular parameters, such as cerebral blood flow (CBF) and cerebral blood volume (CBV), CVR measures the ability of cerebral vessels to dilate or constrict in response to challenges or maneuvers. Therefore, CVR mapping requires a physiological challenge while monitoring the corresponding hemodynamic changes in the brain. The present review primarily focuses on methods that use CO2 inhalation as a physiological challenge while monitoring changes in hemodynamic MRI signals. CO2 inhalation has been increasingly used in CVR mapping in recent literature due to its potency in causing vasodilation, rapid onset and cessation of the effect, as well as advances in MRI-compatible gas delivery apparatus. In this review, we first discuss the physiological basis of CVR mapping using CO2 inhalation. We then review the methodological aspects of CVR mapping, including gas delivery apparatus, the timing paradigm of the breathing challenge, the MRI imaging sequence, and data analysis. In addition, we review alternative approaches for CVR mapping that do not require CO2 inhalation.
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Affiliation(s)
- Peiying Liu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States.
| | - Jill B De Vis
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, 21287, United States; F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, 21205, United States
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20
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Bright MG, Croal PL, Blockley NP, Bulte DP. Multiparametric measurement of cerebral physiology using calibrated fMRI. Neuroimage 2017; 187:128-144. [PMID: 29277404 DOI: 10.1016/j.neuroimage.2017.12.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/07/2023] Open
Abstract
The ultimate goal of calibrated fMRI is the quantitative imaging of oxygen metabolism (CMRO2), and this has been the focus of numerous methods and approaches. However, one underappreciated aspect of this quest is that in the drive to measure CMRO2, many other physiological parameters of interest are often acquired along the way. This can significantly increase the value of the dataset, providing greater information that is clinically relevant, or detail that can disambiguate the cause of signal variations. This can also be somewhat of a double-edged sword: calibrated fMRI experiments combine multiple parameters into a physiological model that requires multiple steps, thereby providing more opportunity for error propagation and increasing the noise and error of the final derived values. As with all measurements, there is a trade-off between imaging time, spatial resolution, coverage, and accuracy. In this review, we provide a brief overview of the benefits and pitfalls of extracting multiparametric measurements of cerebral physiology through calibrated fMRI experiments.
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Affiliation(s)
- Molly G Bright
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Paula L Croal
- IBME, Department of Engineering Science, University of Oxford, Oxford, UK
| | - Nicholas P Blockley
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Daniel P Bulte
- IBME, Department of Engineering Science, University of Oxford, Oxford, UK; FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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21
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Lajoie I, Nugent S, Debacker C, Dyson K, Tancredi FB, Badhwar A, Belleville S, Deschaintre Y, Bellec P, Doyon J, Bocti C, Gauthier S, Arnold D, Kergoat MJ, Chertkow H, Monchi O, Hoge RD. Application of calibrated fMRI in Alzheimer's disease. NEUROIMAGE-CLINICAL 2017; 15:348-358. [PMID: 28560160 PMCID: PMC5443910 DOI: 10.1016/j.nicl.2017.05.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/26/2017] [Accepted: 05/15/2017] [Indexed: 02/07/2023]
Abstract
Calibrated fMRI based on arterial spin-labeling (ASL) and blood oxygen-dependent contrast (BOLD), combined with periods of hypercapnia and hyperoxia, can provide information on cerebrovascular reactivity (CVR), resting blood flow (CBF), oxygen extraction fraction (OEF), and resting oxidative metabolism (CMRO2). Vascular and metabolic integrity are believed to be affected in Alzheimer's disease (AD), thus, the use of calibrated fMRI in AD may help understand the disease and monitor therapeutic responses in future clinical trials. In the present work, we applied a calibrated fMRI approach referred to as Quantitative O2 (QUO2) in a cohort of probable AD dementia and age-matched control participants. The resulting CBF, OEF and CMRO2 values fell within the range from previous studies using positron emission tomography (PET) with 15O labeling. Moreover, the typical parietotemporal pattern of hypoperfusion and hypometabolism in AD was observed, especially in the precuneus, a particularly vulnerable region. We detected no deficit in frontal CBF, nor in whole grey matter CVR, which supports the hypothesis that the effects observed were associated specifically with AD rather than generalized vascular disease. Some key pitfalls affecting both ASL and BOLD methods were encountered, such as prolonged arterial transit times (particularly in the occipital lobe), the presence of susceptibility artifacts obscuring medial temporal regions, and the challenges associated with the hypercapnic manipulation in AD patients and elderly participants. The present results are encouraging and demonstrate the promise of calibrated fMRI measurements as potential biomarkers in AD. Although CMRO2 can be imaged with 15O PET, the QUO2 method uses more widely available imaging infrastructure, avoids exposure to ionizing radiation, and integrates with other MRI-based measures of brain structure and function.
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Affiliation(s)
- Isabelle Lajoie
- Département de Pharmacologie et physiologie, Université de Montréal, Montreal, QC, Canada; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada.
| | - Scott Nugent
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Clément Debacker
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Kenneth Dyson
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Physiology, McGill University, Montreal, QC, Canada
| | - Felipe B Tancredi
- Departamento de Radiologia, Centro de Pesquisa em Imagem, Hospital Israelita Albert Einstein, São Palo, SP, Brazil
| | - AmanPreet Badhwar
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Computer Science and Operations Research, Université de Montréal, Montreal, QC, Canada
| | - Sylvie Belleville
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Psychologie, Université de Montréal, Montreal, QC, Canada
| | - Yan Deschaintre
- Département de Neurosciences, Université de Montréal, Montreal, QC, Canada; Service de neurologie, Département de Médecine, CHUM Notre-Dame, Montréal, QC, Canada
| | - Pierre Bellec
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Computer Science and Operations Research, Université de Montréal, Montreal, QC, Canada
| | - Julien Doyon
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Psychologie, Université de Montréal, Montreal, QC, Canada
| | - Christian Bocti
- Division de Neurologie, Faculté de Médecine et des Sciences de la Santé & Research Centre on Aging, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Serge Gauthier
- McGill Center for Studies in Aging, Douglas Mental Health Research Institute, Montreal, QC, Canada
| | - Douglas Arnold
- Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Marie-Jeanne Kergoat
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Département de Médecine, Université de Montréal, Montreal, QC, Canada
| | - Howard Chertkow
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Oury Monchi
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; McGill Center for Studies in Aging, Douglas Mental Health Research Institute, Montreal, QC, Canada; Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Richard D Hoge
- Département de Pharmacologie et physiologie, Université de Montréal, Montreal, QC, Canada; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada; Montreal Neurological Institute, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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22
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Lajoie I, Tancredi FB, Hoge RD. The impact of inspired oxygen levels on calibrated fMRI measurements of M, OEF and resting CMRO2 using combined hypercapnia and hyperoxia. PLoS One 2017; 12:e0174932. [PMID: 28362834 PMCID: PMC5376305 DOI: 10.1371/journal.pone.0174932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/17/2017] [Indexed: 12/04/2022] Open
Abstract
Recent calibrated fMRI techniques using combined hypercapnia and hyperoxia allow the mapping of resting cerebral metabolic rate of oxygen (CMRO2) in absolute units, oxygen extraction fraction (OEF) and calibration parameter M (maximum BOLD). The adoption of such technique necessitates knowledge about the precision and accuracy of the model-derived parameters. One of the factors that may impact the precision and accuracy is the level of oxygen provided during periods of hyperoxia (HO). A high level of oxygen may bring the BOLD responses closer to the maximum M value, and hence reduce the error associated with the M interpolation. However, an increased concentration of paramagnetic oxygen in the inhaled air may result in a larger susceptibility area around the frontal sinuses and nasal cavity. Additionally, a higher O2 level may generate a larger arterial blood T1 shortening, which require a bigger cerebral blood flow (CBF) T1 correction. To evaluate the impact of inspired oxygen levels on M, OEF and CMRO2 estimates, a cohort of six healthy adults underwent two different protocols: one where 60% of O2 was administered during HO (low HO or LHO) and one where 100% O2 was administered (high HO or HHO). The QUantitative O2 (QUO2) MRI approach was employed, where CBF and R2* are simultaneously acquired during periods of hypercapnia (HC) and hyperoxia, using a clinical 3 T scanner. Scan sessions were repeated to assess repeatability of results at the different O2 levels. Our T1 values during periods of hyperoxia were estimated based on an empirical ex-vivo relationship between T1 and the arterial partial pressure of O2. As expected, our T1 estimates revealed a larger T1 shortening in arterial blood when administering 100% O2 relative to 60% O2 (T1LHO = 1.56±0.01 sec vs. T1HHO = 1.47±0.01 sec, P < 4*10−13). In regard to the susceptibility artifacts, the patterns and number of affected voxels were comparable irrespective of the O2 concentration. Finally, the model-derived estimates were consistent regardless of the HO levels, indicating that the different effects are adequately accounted for within the model.
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Affiliation(s)
- Isabelle Lajoie
- Département de physiologie moléculaire et intégrative, Institut de génie biomédical, Université de Montréal, Montreal, Quebec, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
- * E-mail:
| | - Felipe B. Tancredi
- Departamento de Radiologia, Centro de Pesquisa em Imagem, Hospital Israelita Albert Einstein, São Palo, SP, Brazil
| | - Richard D. Hoge
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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