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Vikner T, Johnson KM, Cadman RV, Betthauser TJ, Wilson RE, Chin N, Eisenmenger LB, Johnson SC, Rivera-Rivera LA. CSF dynamics throughout the ventricular system using 4D flow MRI: associations to arterial pulsatility, ventricular volumes, and age. Fluids Barriers CNS 2024; 21:68. [PMID: 39215377 PMCID: PMC11363656 DOI: 10.1186/s12987-024-00570-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024] Open
Abstract
BACKGROUND Cerebrospinal fluid (CSF) dynamics are increasingly studied in aging and neurological disorders. Models of CSF-mediated waste clearance suggest that altered CSF dynamics could play a role in the accumulation of toxic waste in the CNS, with implications for Alzheimer's disease and other proteinopathies. Therefore, approaches that enable quantitative and volumetric assessment of CSF flow velocities could be of value. In this study we demonstrate the feasibility of 4D flow MRI for simultaneous assessment of CSF dynamics throughout the ventricular system, and evaluate associations to arterial pulsatility, ventricular volumes, and age. METHODS In a cognitively unimpaired cohort (N = 43; age 41-83 years), cardiac-resolved 4D flow MRI CSF velocities were obtained in the lateral ventricles (LV), foramens of Monro, third and fourth ventricles (V3 and V4), the cerebral aqueduct (CA) and the spinal canal (SC), using a velocity encoding (venc) of 5 cm/s. Cerebral blood flow pulsatility was also assessed with 4D flow (venc = 80 cm/s), and CSF volumes were obtained from T1- and T2-weighted MRI. Multiple linear regression was used to assess effects of age, ventricular volumes, and arterial pulsatility on CSF velocities. RESULTS Cardiac-driven CSF dynamics were observed in all CSF spaces, with region-averaged velocity range and root-mean-square (RMS) velocity encompassing from very low in the LVs (RMS 0.25 ± 0.08; range 0.85 ± 0.28 mm/s) to relatively high in the CA (RMS 6.29 ± 2.87; range 18.6 ± 15.2 mm/s). In the regression models, CSF velocity was significantly related to age in 5/6 regions, to CSF space volume in 2/3 regions, and to arterial pulsatility in 3/6 regions. Group-averaged waveforms indicated distinct CSF flow propagation delays throughout CSF spaces, particularly between the SC and LVs. CONCLUSIONS Our findings show that 4D flow MRI enables assessment of CSF dynamics throughout the ventricular system, and captures independent effects of age, CSF space morphology, and arterial pulsatility on CSF motion.
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Affiliation(s)
- Tomas Vikner
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Diagnostics and Intervention, Umeå University, Umeå, S-90187, Sweden
| | - Kevin M Johnson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53726, USA
| | - Robert V Cadman
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Tobey J Betthauser
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Rachael E Wilson
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Nathaniel Chin
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Laura B Eisenmenger
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53726, USA
| | - Sterling C Johnson
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Leonardo A Rivera-Rivera
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA.
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA.
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA.
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Ogbu I, Menon T, Chahil V, Kahlon A, Devanand D, Kalra DK. Sleep Disordered Breathing and Neurocognitive Disorders. J Clin Med 2024; 13:5001. [PMID: 39274214 PMCID: PMC11396397 DOI: 10.3390/jcm13175001] [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: 07/31/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/16/2024] Open
Abstract
Sleep-disordered breathing (SDB), which includes conditions such as obstructive sleep apnea (OSA) and central sleep apnea (CSA), is an independent risk factor for cerebral small vessel disease (CSVD), stroke, heart failure, arrhythmias, and other cardiovascular disorders. The influence of OSA on brain structure and cognitive function has become an essential focus in the heart-brain axis, given its potential role in developing neurocognitive abnormalities. In this review, we found that OSA plays a significant role in the cardio-neural pathway that leads to the development of cerebral small vessel disease and neurocognitive decline. Although data is still limited on this topic, understanding the critical role of OSA in the heart-brain axis could lead to the utilization of imaging modalities to simultaneously identify early signs of pathology in both organ systems based on the known OSA-driven pathological pathways that result in a disease state in both the cardiovascular and cerebrovascular systems. This narrative review aims to summarize the current link between OSA and neurocognitive disorders, cardio-neural pathophysiology, and the treatment options available for patients with OSA-related neurocognitive disorders.
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Affiliation(s)
- Ikechukwu Ogbu
- Department of Cardiology, University of Louisville, Louisville, KY 40202, USA
| | - Tushar Menon
- Department of Cardiology, University of Louisville, Louisville, KY 40202, USA
| | - Vipanpreet Chahil
- Department of Cardiology, University of Louisville, Louisville, KY 40202, USA
| | - Amrit Kahlon
- Department of Cardiology, University of Louisville, Louisville, KY 40202, USA
| | | | - Dinesh K Kalra
- Department of Cardiology, University of Louisville, Louisville, KY 40202, USA
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Vikner T, Garpebring A, Björnfot C, Nyberg L, Malm J, Eklund A, Wåhlin A. Blood-brain barrier integrity is linked to cognitive function, but not to cerebral arterial pulsatility, among elderly. Sci Rep 2024; 14:15338. [PMID: 38961135 PMCID: PMC11222381 DOI: 10.1038/s41598-024-65944-y] [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: 12/09/2023] [Accepted: 06/24/2024] [Indexed: 07/05/2024] Open
Abstract
Blood-brain barrier (BBB) disruption may contribute to cognitive decline, but questions remain whether this association is more pronounced for certain brain regions, such as the hippocampus, or represents a whole-brain mechanism. Further, whether human BBB leakage is triggered by excessive vascular pulsatility, as suggested by animal studies, remains unknown. In a prospective cohort (N = 50; 68-84 years), we used contrast-enhanced MRI to estimate the permeability-surface area product (PS) and fractional plasma volume ( v p ), and 4D flow MRI to assess cerebral arterial pulsatility. Cognition was assessed by the Montreal Cognitive Assessment (MoCA) score. We hypothesized that high PS would be associated with high arterial pulsatility, and that links to cognition would be specific to hippocampal PS. For 15 brain regions, PS ranged from 0.38 to 0.85 (·10-3 min-1) and v p from 0.79 to 1.78%. Cognition was related to PS (·10-3 min-1) in hippocampus (β = - 2.9; p = 0.006), basal ganglia (β = - 2.3; p = 0.04), white matter (β = - 2.6; p = 0.04), whole-brain (β = - 2.7; p = 0.04) and borderline-related for cortex (β = - 2.7; p = 0.076). Pulsatility was unrelated to PS for all regions (p > 0.19). Our findings suggest PS-cognition links mainly reflect a whole-brain phenomenon with only slightly more pronounced links for the hippocampus, and provide no evidence of excessive pulsatility as a trigger of BBB disruption.
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Affiliation(s)
- Tomas Vikner
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden.
- Department of Applied Physics and Electronics, Umeå University, 90187, Umeå, Sweden.
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53792, USA.
| | - Anders Garpebring
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden
| | - Cecilia Björnfot
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden
| | - Lars Nyberg
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187, Umeå, Sweden
- Department of Medical and Translational Biology, Umeå University, 90187, Umeå, Sweden
| | - Jan Malm
- Department of Clinical Science, Neurosciences, Umeå University, 90187, Umeå, Sweden
| | - Anders Eklund
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden
- Department of Applied Physics and Electronics, Umeå University, 90187, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187, Umeå, Sweden
| | - Anders Wåhlin
- Department of Diagnostics and Intervention, Umeå University, 90187, Umeå, Sweden.
- Department of Applied Physics and Electronics, Umeå University, 90187, Umeå, Sweden.
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187, Umeå, Sweden.
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Birnefeld J, Petersson K, Wåhlin A, Eklund A, Birnefeld E, Qvarlander S, Haney M, Malm J, Zarrinkoob L. Cerebral Blood Flow Assessed with Phase-contrast Magnetic Resonance Imaging during Blood Pressure Changes with Noradrenaline and Labetalol: A Trial in Healthy Volunteers. Anesthesiology 2024; 140:669-678. [PMID: 37756527 DOI: 10.1097/aln.0000000000004775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
BACKGROUND Adequate cerebral perfusion is central during general anesthesia. However, perfusion is not readily measured bedside. Clinicians currently rely mainly on mean arterial pressure (MAP) as a surrogate, even though the relationship between blood pressure and cerebral blood flow is not well understood. The aim of this study was to apply phase-contrast magnetic resonance imaging to characterize blood flow responses in healthy volunteers to commonly used pharmacologic agents that increase or decrease arterial blood pressure. METHODS Eighteen healthy volunteers aged 30 to 50 yr were investigated with phase-contrast magnetic resonance imaging. Intra-arterial blood pressure monitoring was used. First, intravenous noradrenaline was administered to a target MAP of 20% above baseline. After a wash-out period, intravenous labetalol was given to a target MAP of 15% below baseline. Cerebral blood flow was measured using phase-contrast magnetic resonance imaging and defined as the sum of flow in the internal carotid arteries and vertebral arteries. Cardiac output (CO) was defined as the flow in the ascending aorta. RESULTS Baseline median cerebral blood flow was 772 ml/min (interquartile range, 674 to 871), and CO was 5,874 ml/min (5,199 to 6,355). The median dose of noradrenaline was 0.17 µg · kg-1 · h-1 (0.14 to 0.22). During noradrenaline infusion, cerebral blood flow decreased to 705 ml/min (606 to 748; P = 0.001), and CO decreased to 4,995 ml/min (4,705 to 5,635; P = 0.01). A median dose of labetalol was 120 mg (118 to 150). After labetalol boluses, cerebral blood flow was unchanged at 769 ml/min (734 to 900; P = 0.68). CO increased to 6,413 ml/min (6,056 to 7,464; P = 0.03). CONCLUSIONS In healthy, awake subjects, increasing MAP using intravenous noradrenaline decreased cerebral blood flow and CO. These data do not support inducing hypertension with noradrenaline to increase cerebral blood flow. Cerebral blood flow was unchanged when decreasing MAP using labetalol. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Johan Birnefeld
- Department of Clinical Sciences, Neurosciences, Umeå University, Umeå, Sweden
| | - Karl Petersson
- Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine Unit, Umeå University, Umeå, Sweden
| | - Anders Wåhlin
- Departments of Radiation Sciences, Biomedical Engineering and Applied Physics and Electronics and Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Departments of Radiation Sciences, Biomedical Engineering and Applied Physics and Electronics, Umeå University, Umeå, Sweden
| | - Elin Birnefeld
- Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine Unit, Umeå University, Umeå, Sweden
| | - Sara Qvarlander
- Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden
| | - Michael Haney
- Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine Unit, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Clinical Sciences, Neurosciences, Umeå University, Umeå, Sweden
| | - Laleh Zarrinkoob
- Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine Unit, Umeå University, Umeå, Sweden
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Straccia A, Chassagne F, Bass DI, Barros G, Leotta DF, Sheehan F, Sharma D, Levitt MR, Aliseda A. A Novel Patient-Specific Computational Fluid Dynamics Study of the Activation of Primary Collateral Pathways in the Circle of Willis During Vasospasm. J Biomech Eng 2023; 145:041008. [PMID: 36173034 PMCID: PMC9791673 DOI: 10.1115/1.4055813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/17/2022] [Indexed: 12/30/2022]
Abstract
The Circle of Willis (CoW) is a redundant network of blood vessels that perfuses the brain. The ringlike anatomy mitigates the negative effects of stroke by activating collateral pathways that help maintain physiological perfusion. Previous studies have investigated the activation of these pathways during embolic stroke and internal carotid artery occlusion. However, the role of collateral pathways during cerebral vasospasm-an involuntary constriction of blood vessels after subarachnoid hemorrhage-is not well-documented. This study presents a novel technique to create patient-specific computational fluid dynamics (CFD) simulations of the Circle of Willis before and during vasospasm. Computed tomographic angiography (CTA) scans are segmented to model the vasculature, and transcranial Doppler ultrasound (TCD) measurements of blood flow velocity are applied as boundary conditions. Bayesian analysis leverages information about the uncertainty in the measurements of vessel diameters and velocities to find an optimized parameter set that satisfies mass conservation and that is applied in the final simulation. With this optimized parameter set, the diameters, velocities, and flow rates fall within typical literature values. Virtual angiograms modeled using passive scalar transport agree closely with clinical angiography. A sensitivity analysis quantifies the changes in collateral flow rates with respect to changes in the inlet and outlet flow rates. This analysis can be applied in the future to a cohort of patients to investigate the relationship between the locations and severities of vasospasm, the patient-to-patient anatomical variability in the Circle of Willis, and the activation of collateral pathways.
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Affiliation(s)
- Angela Straccia
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Seattle, WA 98195
| | - Fanette Chassagne
- INSERM U1059 Sainboise, Mines Saint-Étienne, 158 cours Fauriel, Saint-Étienne 42000, France
| | - David I. Bass
- Department of Neurological Surgery, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104
| | - Guilherme Barros
- Department of Neurological Surgery, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104
| | - Daniel F. Leotta
- Applied Physics Laboratory, University of Washington, 1013 NE 40th 28 St, Box 355640, Seattle, WA 98105
| | - Florence Sheehan
- Department of Medicine, University of Washington, 1959 NE Pacific St, RR-616, Seattle, WA 98195
| | - Deepak Sharma
- Department of Neurological Surgery, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104
| | - Michael R. Levitt
- Department of Neurological Surgery, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104; Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Seattle, WA 98195; Department of Radiology, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Seattle, WA 98195; Department of Neurological Surgery, University of Washington, 325 Ninth Avenue, Box 359924, Seattle, WA 98104
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Liu C, Lee SH, Loewenstein DA, Galvin JE, Levin BE, McKinney A, Alperin N. Early Amnestic Mild Cognitive Impairment Is Associated with Reduced Total Cerebral Blood Flow with no Brain Tissue Loss. J Alzheimers Dis 2023; 91:1313-1322. [PMID: 36617780 DOI: 10.3233/jad-220734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Lower cerebral blood flow (CBF) and excessive brain atrophy are linked to Alzheimer's disease (AD). It is still undetermined whether reduced CBF precedes or follows brain tissue loss. OBJECTIVE We compared total CBF (tCBF), global cerebral perfusion (GCP), and volumes of AD-prone regions between cognitively normal (CN) and early amnestic mild cognitive impairment (aMCI) and tested their associations with cognitive performance to assess their predictive value for differentiation between CN and early aMCI. METHODS A total of 74 participants (mean age 69.9±6.2 years, 47 females) were classified into two groups: 50 CN and 24 aMCI, of whom 88% were early aMCI. tCBF, GCP, and global and regional brain volumetry were measured using phase-contrast and T1-weighted MRI. Neuropsychological tests tapping global cognition and four cognitive domains (memory, executive function, language, and visuospatial) were administered. Comparisons and associations were investigated using analyses of covariance (ANCOVA) and linear regression analyses, respectively. RESULTS Women had significantly higher GCP than men. Both, tCBF and GCP were significantly reduced in aMCI compared with CN, while differences in volumes of cerebral gray matter, white matter, and AD-prone regions were not significant. tCBF and GCP were significantly associated with global cognition (standardized beta (stβ) = 0.324 and stβ= 0.326) and with memory scores (stβ≥0.297 and stβ≥0.264) across all participants. Associations of tCBF and GCP with memory scores were also significant in CN (stβ= 0.327 and stβ= 0.284) and in aMCI (stβ= 0.627 and stβ= 0.485). CONCLUSION Reduced tCBF and GCP are sensitive biomarkers of early aMCI that likely precede brain tissue loss.
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Affiliation(s)
- Che Liu
- Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Biomedical Engineering, University of Miami, Miami, FL, USA.,Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sang H Lee
- Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - David A Loewenstein
- Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, USA
| | - James E Galvin
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bonnie E Levin
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Alexander McKinney
- Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Noam Alperin
- Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Biomedical Engineering, University of Miami, Miami, FL, USA.,Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA
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Fu M, Peng F, Niu H, He X, Chen S, Zhang M, Xia J, Wang Y, Xu B, Liu A, Li R. Inflow Angle Impacts Morphology, Hemodynamics, and Inflammation of Side-wall Intracranial Aneurysms. J Magn Reson Imaging 2023; 57:113-123. [PMID: 35652452 DOI: 10.1002/jmri.28234] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Aneurysm inflow angle has been shown to be associated with hemodynamic changes by computational fluid dynamics. However, these studies were based on single aneurysm model and were limited to side-wall aneurysms. PURPOSE To investigate the association between inflow angle and morphology, hemodynamic, and inflammation of intracranial side-wall and bifurcation aneurysms. STUDY TYPE Prospective. POPULATION A total of 62 patients (aged 58.34 ± 12.39, 44 female) with 59 unruptured side-wall aneurysms and 17 unruptured bifurcation aneurysms were included. FIELD STRENGTH/SEQUENCE A 3.0 T; 3D fast field echo sequence (TOF-MRA); free-breathing, 3D radio-frequency-spoiled, multi-shot turbo field echo sequence (4D-flow MRI); 3D black-blood T1-weighted volumetric turbo spin echo acquisition sequence (T1 -VISTA) ASSESSMENT: Two neuroradiologists assessed the inflow angle and size for intracranial aneurysms in 3D space with TOF-MRA images. The average and maximum inflow velocity (Vavg-IA , Vmax-IA ), blood flow (Flowavg-IA , Flowmax-IA ), and average wall shear stress (WSSavg-IA ) for aneurysms were assessed from 4D-flow MRI in regions of interest drawn by two neuroradiologists. The aneurysmal wall enhancement (AWE) grades between precontrast and postcontrast T1 -VISTA images were evaluated by three neuroradiologists. STATISTICAL TESTS Kruskal-Wallis H test, χ2 test, Pearson's correlation coefficient, scatter plots and regression lines, multivariate logistic regression analysis (partial correlation r) were performed. A P < 0.05 was considered statistically significant. RESULTS The WSSavg-IA (0.52 ± 0.34 vs. 0.27 ± 0.22) and AWE grades (1.38 ± 1.04 vs. 2.02 ± 0.68) between the two inflow angle subgroups of side-wall aneurysms were significantly different. The aneurysm size (rs = 0.31), WSSavg-IA (rs = -0.45), and AWE grades (rs = 0.45) were significantly correlated with inflow angle in side-wall aneurysms. While in bifurcation aneurysms, there were no significant associations between inflow angle and size (P = 0.901), Vavg-IA (P = 0.699), Vmax-IA (P = 0.482), Flowavg-IA (P = 0.550), Flowmax-IA (P = 0.689), WSSavg-IA (P = 0.573), and AWE grades (P = 0.872). DATA CONCLUSION A larger aneurysm size, a lower WSS and a higher AWE grade were correlated with a larger inflow angle in side-wall aneurysms. EVIDENCE LEVEL 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Mingzhu Fu
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | - Fei Peng
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Hao Niu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Xiaoxin He
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Shuo Chen
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | - Miaoqi Zhang
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | - Jiaxiang Xia
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | | | - Boya Xu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Aihua Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing, China
| | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China
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Johnson S, Dwivedi A, Mirza M, McCarthy R, Gilvarry M. A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:879074. [PMID: 35756535 PMCID: PMC9214215 DOI: 10.3389/fmedt.2022.879074] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
In-vitro neurovascular models of large vessel occlusions (LVOs) causing acute ischemic stroke (AIS) are used extensively for pre-clinical testing of new treatment devices. They enable physicians and engineers to examine device performance and the response of the occlusion to further advance design solutions for current unmet clinical needs. These models also enable physicians to train on basic skills, to try out new devices and new procedural approaches, and for the stroke team to practice workflows together in the comfort of a controlled environment in a non-clinical setting. Removal of the occlusive clot in its entirety is the primary goal of the endovascular treatment of LVOs via mechanical thrombectomy (MT) and the medical treatment via thrombolysis. In MT, recanalization after just one pass is associated with better clinical outcomes than procedures that take multiple passes to achieve the same level of recanalization, commonly known as first pass effect (FPE). To achieve this, physicians and engineers are continually investigating new devices and treatment approaches. To distinguish between treatment devices in the pre-clinical setting, test models must also be optimized and expanded become more nuanced and to represent challenging patient cohorts that could be improved through new technology or better techniques. The aim of this paper is to provide a perspective review of the recent advancements in the in-vitro modeling of stroke and to outline how these models need to advance further in future. This review provides an overview of the various in-vitro models used for the modeling of AIS and compares the advantages and limitations of each. In-vitro models remain an extremely useful tool in the evaluation and design of treatment devices, and great strides have been made to improve replication of physiological conditions. However, further advancement is still required to represent the expanding indications for thrombectomy and thrombolysis, and the generation of new thrombectomy devices, to ensure that smaller treatment effects are captured.
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Affiliation(s)
- Sarah Johnson
- Cerenovus (Johnson & Johnson), Galway Neuro Technology Centre, Galway, Ireland
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9
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Töger J, Andersen M, Haglund O, Kylkilahti TM, Lundgaard I, Markenroth Bloch K. Real‐time imaging of respiratory effects on cerebrospinal fluid flow in small diameter passageways. Magn Reson Med 2022; 88:770-786. [PMID: 35403247 PMCID: PMC9324219 DOI: 10.1002/mrm.29248] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/01/2022] [Accepted: 03/08/2022] [Indexed: 12/03/2022]
Abstract
Purpose Respiration‐related CSF flow through the cerebral aqueduct may be useful for elucidating physiology and pathophysiology of the glymphatic system, which has been proposed as a mechanism of brain waste clearance. Therefore, we aimed to (1) develop a real‐time (CSF) flow imaging method with high spatial and sufficient temporal resolution to capture respiratory effects, (2) validate the method in a phantom setup and numerical simulations, and (3) apply the method in vivo and quantify its repeatability and correlation with different respiratory conditions. Methods A golden‐angle radial flow sequence (reconstructed temporal resolution 168 ms, spatial resolution 0.6 mm) was implemented on a 7T MRI scanner and reconstructed using compressed sensing. A phantom setup mimicked simultaneous cardiac and respiratory flow oscillations. The effect of temporal resolution and vessel diameter was investigated numerically. Healthy volunteers (n = 10) were scanned at four different respiratory conditions, including repeat scans. Results Phantom data show that the developed sequence accurately quantifies respiratory oscillations (ratio real‐time/reference QR = 0.96 ± 0.02), but underestimates the rapid cardiac oscillations (ratio QC = 0.46 ± 0.14). Simulations suggest that QC can be improved by increasing temporal resolution. In vivo repeatability was moderate to very strong for cranial and caudal flow (intraclass correlation coefficient range: 0.55–0.99) and weak to strong for net flow (intraclass correlation coefficient range: 0.48–0.90). Net flow was influenced by respiratory condition (p < 0.01). Conclusions The presented real‐time flow MRI method can quantify respiratory‐related variations of CSF flow in the cerebral aqueduct, but it underestimates rapid cardiac oscillations. In vivo, the method showed good repeatability and a relationship between flow and respiration.
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Affiliation(s)
- Johannes Töger
- Department of Clinical Sciences Lund, Diagnostic Radiology Lund University, Skåne University Hospital Lund Sweden
| | - Mads Andersen
- Philips Healthcare Copenhagen Denmark
- Lund University, Lund University Bioimaging Center Lund Sweden
| | - Olle Haglund
- Department of Medical Radiation Physics Lund University Lund Sweden
| | - Tekla Maria Kylkilahti
- Department of Experimental Medical Science Lund University Lund Sweden
- Wallenberg Centre for Molecular Medicine Lund University Lund Sweden
| | - Iben Lundgaard
- Department of Experimental Medical Science Lund University Lund Sweden
- Wallenberg Centre for Molecular Medicine Lund University Lund Sweden
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10
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Baselli G, Laganà MM. The intracranial Windkessel implies arteriovenous pulsatile coupling increased by venous resistances. Biomed Signal Process Control 2022. [DOI: 10.1016/j.bspc.2021.103092] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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11
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Yavuz Ilik S, Otani T, Yamada S, Watanabe Y, Wada S. A subject-specific assessment of measurement errors and their correction in cerebrospinal fluid velocity maps using 4D flow MRI. Magn Reson Med 2021; 87:2412-2423. [PMID: 34866235 DOI: 10.1002/mrm.29111] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 11/05/2022]
Abstract
PURPOSE Phase-contrast MRI (PC-MRI) of cerebrospinal fluid (CSF) velocity is used to evaluate the characteristics of intracranial diseases, such as normal-pressure hydrocephalus (NPH). Nevertheless, PC-MRI has several potential error sources, with eddy-current-based phase offset error being non-negligible in CSF measurement. In this study, we assess the measurement error of CSF velocity maps obtained using 4D flow MRI and evaluate correction methods. METHODS CSF velocity maps of 10 patients with NPH were acquired using 4D flow MRI (velocity-encoding = 5 cm/s). Distributed phase offset error was estimated for a whole 3D background field by polynomial fitting using robust regression analysis. This estimated phase offset error was then used to correct the CSF velocity maps. The estimated error profiles were compared with those obtained using an existing 2D correction approach involving local background information near the region of interest. RESULTS The residual standard error of the polynomial fitting against the phase offset error extracted from the measured velocities was within 0.2 cm/s. The spatial dependencies of the phase offset errors showed similar tendencies in all cases, but sufficient differences in these values were found to indicate requirement of velocity correction. Differences of the estimated errors among other correction approaches were in the order of 10-2 cm/s, and the estimated errors were in good agreement with those obtained using existing approaches. CONCLUSION Our method is capable of estimating the measurement error of CSF velocity maps obtained from 4D flow MRI and provides quantitatively reasonable characteristics for the main CSF profile in the cerebral aqueduct in patients with NPH.
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Affiliation(s)
- Selin Yavuz Ilik
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
| | - Tomohiro Otani
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
| | - Shigeki Yamada
- Department of Neurosurgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yoshiyuki Watanabe
- Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Shigeo Wada
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
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12
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Lee J, Gupta AN, Ma LE, Scott MB, Mason OR, Wu E, Thomas JD, Markl M. Valvular regurgitation flow jet assessment using in vitro 4D flow MRI: Implication for mitral regurgitation. Magn Reson Med 2021; 87:1923-1937. [PMID: 34783383 DOI: 10.1002/mrm.29082] [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: 06/25/2021] [Revised: 10/01/2021] [Accepted: 10/25/2021] [Indexed: 11/11/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the accuracy of four-dimensional (4D) flow MRI for direct assessment of peak velocity, flow volume, and momentum of a mitral regurgitation (MR) flow jets using an in vitro pulsatile jet flow phantom. We systematically investigated the impact of spatial resolution and quantification location along the jet on flow quantities with Doppler ultrasound as a reference for peak velocity. METHODS Four-dimensional flow MRI data of a pulsatile jet through a circular, elliptical, and 3D-printed patient-specific MR orifice model was acquired with varying spatial resolution (1.5-5 mm isotropic voxel). Flow rate and momentum of the jet were quantified at various axial distances (x = 0-50 mm) and integrated over time to calculate Voljet and MTIjet . In vivo assessment of Voljet and MTIjet was performed on 3 MR patients. RESULTS Peak velocities were comparable to Doppler ultrasound (3% error, 1.5 mm voxel), but underestimated with decreasing spatial resolution (-40% error, 5 mm voxel). Voljet was similar to regurgitant volume (RVol) within 5 mm, and then increased linearly with the axial distance (19%/cm) because of flow entrainment. MTIjet remained steady throughout the jet (2%/cm) as theoretically predicted. Four and 9 voxels across the jet were required to measure flow volume and momentum-time-integral within 10% error, respectively. CONCLUSION Four-dimensional flow MRI detected accurate peak velocity, flow rate, and momentum for in vitro MR-mimicking flow jets. Spatial resolution significantly impacted flow quantitation, which otherwise followed predictions of flow entrainment and momentum conservation. This study provides important preliminary information for accurate in vivo MR assessment using 4D flow MRI.
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Affiliation(s)
- Jeesoo Lee
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Aakash N Gupta
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Liliana E Ma
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Michel B Scott
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - O'Neil R Mason
- Division of Cardiology, Northwestern Memorial Hospital, Chicago, Illinois, USA
| | - Erik Wu
- Division of Cardiology, Northwestern Memorial Hospital, Chicago, Illinois, USA
| | - James D Thomas
- Division of Cardiology, Northwestern Memorial Hospital, Chicago, Illinois, USA
| | - Michael Markl
- Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.,Department of Biomedical Engineering, Northwestern University, McCormick School of Engineering, Evanston, Illinois, USA
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13
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Mohammadi H, Vincent T, Peng K, Nigam A, Gayda M, Fraser S, Joanette Y, Lesage F, Bherer L. Coronary artery disease and its impact on the pulsatile brain: A functional NIRS study. Hum Brain Mapp 2021; 42:3760-3776. [PMID: 33991155 PMCID: PMC8288102 DOI: 10.1002/hbm.25463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/16/2022] Open
Abstract
Recent studies have reported that optical indices of cerebral pulsatility are associated with cerebrovascular health in older adults. Such indices, including cerebral pulse amplitude and the pulse relaxation function (PRF), have been previously applied to quantify global and regional cerebral pulsatility. The aim of the present study was to determine whether these indices are modulated by cardiovascular status and whether they differ between individuals with low or high cardiovascular risk factors (LCVRF and HCVRF) and coronary artery disease (CAD). A total of 60 older adults aged 57-79 were enrolled in the study. Participants were grouped as LCVRF, HCVRF, and CAD. Participants were asked to walk freely on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data. Low-intensity, short-duration walking was used to test whether a brief cardiovascular challenge could increase the difference of pulsatility indices with respect to cardiovascular status. Results indicated that CAD individuals have higher global cerebral pulse amplitude compared with the other groups. Walking reduced global cerebral pulse amplitude and PRF in all groups but did not increase the difference across the groups. Instead, walking extended the spatial distribution of cerebral pulse amplitude to the anterior prefrontal cortex when CAD was compared to the CVRF groups. Further research is needed to determine whether cerebral pulse amplitude extracted from data acquired with NIRS, which is a noninvasive, inexpensive method, can provide an index to characterize the cerebrovascular status associated with CAD.
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Affiliation(s)
- Hanieh Mohammadi
- Laboratory of Optical and Molecular ImagingBiomedical Engineering Institute, Polytechnique MontrealQuebecCanada
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Thomas Vincent
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Ke Peng
- Center for Pain and the BrainBoston Children's Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Research CenterUniversity of Montreal Health CentreMontrealQuebecCanada
| | - Anil Nigam
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Mathieu Gayda
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Sarah Fraser
- Interdisciplinary School of Health Sciences, Faculty of Health SciencesUniversity of OttawaOttawaOntarioCanada
| | - Yves Joanette
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Faculty of MedicineUniversity of MontrealMontrealQuebecCanada
| | - Frédéric Lesage
- Laboratory of Optical and Molecular ImagingBiomedical Engineering Institute, Polytechnique MontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Louis Bherer
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
- Faculty of MedicineUniversity of MontrealMontrealQuebecCanada
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14
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Kristiansen M, Lindén C, Qvarlander S, Wåhlin A, Ambarki K, Hallberg P, Eklund A, Jóhannesson G. Feasibility of MRI to assess differences in ophthalmic artery blood flow rate in normal tension glaucoma and healthy controls. Acta Ophthalmol 2021; 99:e679-e685. [PMID: 33210819 PMCID: PMC8451810 DOI: 10.1111/aos.14673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/05/2020] [Accepted: 10/14/2020] [Indexed: 11/30/2022]
Abstract
Purpose To examine feasibility of phase‐contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods Sixteen patients with treated NTG and 16 age‐ and sex‐matched healthy controls underwent PCMRI using a 3‐Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm2. Results The blood flow rate in the NTG group was 9.6 ± 3.9 ml/min [mean ± SD] compared with 11.9 ± 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 ± 0.08 and 1.36 ± 0.29, respectively, in the NTG group and 0.68 ± 0.13 and 1.22 ± 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% ± 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non‐significant. Conclusions This case–control study, using PCMRI, showed a slight, but non‐significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter‐individual differences, a larger study or more advanced PCMRI technique might give the answer.
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Affiliation(s)
- Martin Kristiansen
- Department of Clinical Sciences Ophthalmology Umeå University Umeå Sweden
| | - Christina Lindén
- Department of Clinical Sciences Ophthalmology Umeå University Umeå Sweden
| | - Sara Qvarlander
- Department of Radiation Sciences Biomedical Engineering Umeå University Umeå Sweden
- Centre for Biomedical Engineering and Physics Umeå University Umeå Sweden
| | - Anders Wåhlin
- Department of Radiation Sciences Biomedical Engineering Umeå University Umeå Sweden
- Centre for Biomedical Engineering and Physics Umeå University Umeå Sweden
- Umeå Center for Functional Brain Imaging Umeå University Umeå Sweden
| | - Khalid Ambarki
- Department of Radiation Sciences Biomedical Engineering Umeå University Umeå Sweden
- Centre for Biomedical Engineering and Physics Umeå University Umeå Sweden
| | - Per Hallberg
- Centre for Biomedical Engineering and Physics Umeå University Umeå Sweden
- Dept. of Applied Physics and Electronics Umeå University Umeå Sweden
| | - Anders Eklund
- Department of Radiation Sciences Biomedical Engineering Umeå University Umeå Sweden
- Centre for Biomedical Engineering and Physics Umeå University Umeå Sweden
| | - Gauti Jóhannesson
- Department of Clinical Sciences Ophthalmology Umeå University Umeå Sweden
- Wallenberg Center for Molecular Medicine Umeå University Umeå Sweden
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15
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Using deep learning convolutional neural networks to automatically perform cerebral aqueduct CSF flow analysis. J Clin Neurosci 2021; 90:60-67. [PMID: 34275582 DOI: 10.1016/j.jocn.2021.05.010] [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: 03/04/2021] [Revised: 04/11/2021] [Accepted: 05/01/2021] [Indexed: 11/22/2022]
Abstract
Since the development of phase-contrast magnetic resonance imaging (PC-MRI), quantification of cerebrospinal fluid (CSF) flow across the cerebral aqueduct has been utilized for diagnosis of conditions such as normal pressure hydrocephalus (NPH). This study aims to develop an automated method of aqueduct CSF flow analysis using convolution neural networks (CNNs), which can replace the current standard involving manual segmentation of aqueduct region of interest (ROI). Retrospective analysis was performed on 333 patients who underwent PC-MRI, totaling 353 imaging studies. Aqueduct flow measurements using manual ROI placement was performed independently by two radiologists. Two types of CNNs, MultiResUNet and UNet, were trained using ROI data from the senior radiologist, with PC-MRI studies being randomly divided into training (80%) and validation (20%) datasets. Segmentation performance was assessed using Dice similarity coefficient (DSC), and CSF flow parameters were calculated from both manual and CNN-derived ROIs. MultiResUNet, UNet and second radiologist (Rater 2) had DSCs of 0.933, 0.928, and 0.867, respectively, with p < 0.001 between CNNs and Rater 2. Comparison of CSF flow parameters showed excellent intraclass correlation coefficients (ICCs) for MultiResUNet, with lowest correlation being 0.67. For UNet, lower ICCs of -0.01 to 0.56 were observed. Only 3/353 (0.8%) studies failed to have appropriate ROIs placed by MultiResUNet, compared to 12/353 (3.4%) failed cases for UNet. In conclusion, CNNs were able to measure aqueductal CSF flow with similar performance to a senior neuroradiologist. MultiResUNet demonstrated fewer cases of segmentation failure and more consistent flow measurements compared to the widely adopted UNet.
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16
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Cortical thinning is associated with brain pulsatility in older adults: An MRI and NIRS study. Neurobiol Aging 2021; 106:103-118. [PMID: 34274697 DOI: 10.1016/j.neurobiolaging.2021.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 03/29/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022]
Abstract
Aging is accompanied by global brain atrophy occurring unequally across the brain. Cortical thinning is seen with aging with a larger loss in the frontal and temporal subregions. We explored the link between regional cortical thickness and regional cerebral pulsatility. Sixty healthy individuals were divided into two age groups, young (aged 19-31) and older (aged 65-75) adults. Each participant underwent a near-infrared spectroscopy (NIRS) scan to index regional brain pulsatility from cerebral pulse-transit-time-to-the peak-of-the-pulse (PTTp), an anatomical magnetic resonance imaging (MRI) and a phase-contrast MRI (PC-MRI) scan to measure arterial and cerebrospinal fluid (CSF) pulsatility. In older adults, the greatest association between cerebral pulsatility and cortical thickness was found in superior and middle temporal and superior, middle and inferior frontal areas, which are the regions perfused first by the internal carotid arteries. This association dropped in the postcentral and superior parietal regions. These findings suggest higher brain pulsatility as a potential risk factor contributing to cortical thinning for some brain regions more than others.
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17
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van Hespen KM, Kuijf HJ, Hendrikse J, Luijten PR, Zwanenburg JJM. Blood Flow Velocity Pulsatility and Arterial Diameter Pulsatility Measurements of the Intracranial Arteries Using 4D PC-MRI. Neuroinformatics 2021; 20:317-326. [PMID: 34019208 PMCID: PMC9546978 DOI: 10.1007/s12021-021-09526-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2021] [Indexed: 10/28/2022]
Abstract
4D phase contrast magnetic resonance imaging (PC-MRI) allows for the visualization and quantification of the cerebral blood flow. A drawback of software that is used to quantify the cerebral blood flow is that it oftentimes assumes a static arterial luminal area over the cardiac cycle. Quantifying the lumen area pulsatility index (aPI), i.e. the change in lumen area due to an increase in distending pressure over the cardiac cycle, can provide insight in the stiffness of the arteries. Arterial stiffness has received increased attention as a predictor in the development of cerebrovascular disease. In this study, we introduce software that allows for measurement of the aPI as well as the blood flow velocity pulsatility index (vPI) from 4D PC-MRI. The internal carotid arteries of seven volunteers were imaged using 7 T MRI. The aPI and vPI measurements from 4D PC-MRI were validated against measurements from 2D PC-MRI at two levels of the internal carotid arteries (C3 and C7). The aPI and vPI computed from 4D PC-MRI were comparable to those measured from 2D PC-MRI (aPI: mean difference: 0.03 (limits of agreement: -0.14 - 0.23); vPI: 0.03 (-0.17-0.23)). The measured blood flow rate for the C3 and C7 segments was similar, indicating that our proposed software correctly captures the variation in arterial lumen area and blood flow velocity that exists along the distal end of the carotid artery. Our software may potentially aid in identifying changes in arterial stiffness of the intracranial arteries caused by pathological changes to the vessel wall.
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Affiliation(s)
| | - Hugo J Kuijf
- Image Sciences Institute, UMC Utrecht, Utrecht, The Netherlands
| | | | - Peter R Luijten
- Department of Radiology, UMC Utrecht, Utrecht, The Netherlands
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18
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Sloots JJ, Biessels GJ, de Luca A, Zwanenburg JJM. Strain Tensor Imaging: Cardiac-induced brain tissue deformation in humans quantified with high-field MRI. Neuroimage 2021; 236:118078. [PMID: 33878376 DOI: 10.1016/j.neuroimage.2021.118078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/02/2021] [Accepted: 04/07/2021] [Indexed: 11/15/2022] Open
Abstract
The cardiac cycle induces blood volume pulsations in the cerebral microvasculature that cause subtle deformation of the surrounding tissue. These tissue deformations are highly relevant as a potential source of information on the brain's microvasculature as well as of tissue condition. Besides, cyclic brain tissue deformations may be a driving force in clearance of brain waste products. We have developed a high-field magnetic resonance imaging (MRI) technique to capture these tissue deformations with full brain coverage and sufficient signal-to-noise to derive the cardiac-induced strain tensor on a voxel by voxel basis, that could not be assessed non-invasively before. We acquired the strain tensor with 3 mm isotropic resolution in 9 subjects with repeated measurements for 8 subjects. The strain tensor yielded both positive and negative eigenvalues (principle strains), reflecting the Poison effect in tissue. The principle strain associated with expansion followed the known funnel shaped brain motion pattern pointing towards the foramen magnum. Furthermore, we evaluate two scalar quantities from the strain tensor: the volumetric strain and octahedral shear strain. These quantities showed consistent patterns between subjects, and yielded repeatable results: the peak systolic volumetric strain (relative to end-diastolic strain) was 4.19⋅10-4 ± 0.78⋅10-4 and 3.98⋅10-4 ± 0.44⋅10-4 (mean ± standard deviation for first and second measurement, respectively), and the peak octahedral shear strain was 2.16⋅10-3 ± 0.31⋅10-3 and 2.31⋅10-3 ± 0.38⋅10-3, for the first and second measurement, respectively. The volumetric strain was typically highest in the cortex and lowest in the periventricular white matter, while anisotropy was highest in the subcortical white matter and basal ganglia. This technique thus reveals new, regional information on the brain's cardiac-induced deformation characteristics, and has the potential to advance our understanding of the role of microvascular pulsations in health and disease.
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Affiliation(s)
| | - Geert Jan Biessels
- Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, the Netherlands
| | - Alberto de Luca
- Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, the Netherlands
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Zarrinkoob L, Wåhlin A, Ambarki K, Eklund A, Malm J. Quantification and mapping of cerebral hemodynamics before and after carotid endarterectomy, using four-dimensional flow magnetic resonance imaging. J Vasc Surg 2021; 74:910-920.e1. [PMID: 33812036 DOI: 10.1016/j.jvs.2021.01.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/26/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Carotid stenosis can profoundly affect cerebral hemodynamics, which cannot simply be inferred from the degree of stenosis. We quantified and mapped the distribution of the blood flow rate (BFR) in the cerebral arteries before and after carotid endarterectomy using four-dimensional (4D) phase-contrast (PC) magnetic resonance imaging (MRI). METHODS Nineteen patients (age, 71 ± 6 years; 2 women) with symptomatic carotid stenosis (≥50%) undergoing carotid endarterectomy (CEA) were investigated using 4D PC-MRI before and after surgery. The BFR was measured in 17 cerebral arteries and the ophthalmic arteries. Collateral recruitment through the anterior and posterior communicating arteries, ophthalmic arteries, and leptomeningeal arteries was quantified. BFR laterality was significantly different between the paired contralateral and ipsilateral arteries. Subgroups were defined according to the presence of collateral recruitment. RESULTS The total cerebral blood flow had increased by 15% (P < .01) after CEA. Before CEA, laterality was seen in the internal carotid artery, anterior cerebral artery, and middle cerebral artery (MCA). On the ipsilateral side, an increased BFR was found after CEA in the internal carotid artery (246 ± 62 mL/min vs 135 ± 80 mL/min; P < .001), anterior cerebral artery (87 ± mL/min vs 38 ± 58 mL/min; P < .01), and MCA (149 ± 43 mL/min vs 119 ± 34 mL/min; P < .01), resulting in a postoperative BFR distribution without signs of laterality. In the nine patients with preoperatively recruited collaterals, BFR laterality was found in the MCA before, but not after, CEA (P < .01). This laterality was not found in the 10 patients without collateral recruitment (P = .2). The degree of stenosis did not differ between the groups with and without collateral recruitment (P = .85). CONCLUSIONS Using 4D PC-MRI, we have presented a comprehensive and noninvasive method to evaluate the cerebral hemodynamics due to carotid stenosis before and after CEA. MCA laterality, seen in the patients with collateral recruitment before CEA, pointed toward a hemodynamic disturbance in MCA territory for those patients. This methodologic advancement provides an insight into the pathophysiology of cerebral hemodynamics in patients with carotid stenosis.
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Affiliation(s)
- Laleh Zarrinkoob
- Division of Neuroscience, Department of Clinical Sciences, Umeå University, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden.
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden; Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Khalid Ambarki
- Department of Radiation Sciences, Umeå University, Umeå, Sweden; Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden; Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden
| | - Jan Malm
- Division of Neuroscience, Department of Clinical Sciences, Umeå University, Umeå, Sweden
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Laganà MM, Jakimovski D, Bergsland N, Dwyer MG, Baglio F, Zivadinov R. Measuring Aqueduct of Sylvius Cerebrospinal Fluid Flow in Multiple Sclerosis Using Different Software. Diagnostics (Basel) 2021; 11:325. [PMID: 33671219 PMCID: PMC7923004 DOI: 10.3390/diagnostics11020325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/14/2021] [Indexed: 01/02/2023] Open
Abstract
Aqueduct of Sylvius (AoS) cerebrospinal fluid flow can be quantified using phase-contrast (PC) Magnetic Resonance Imaging. The software used for AoS segmentation might affect the PC-derived measures. We analyzed AoS PC data of 30 people with multiple sclerosis and 19 normal controls using three software packages, and estimated cross-sectional area (CSA), average and highest AoS velocity (Vmean and Vmax), flow rate and volume. Our aims were to assess the repeatability and reproducibility of each PC-derived measure obtained with the various software packages, including in terms of group differentiation. All the variables had good repeatability, except the average Vmean, flow rate and volume obtained with one software package. Substantial to perfect agreement was seen when evaluating the overlap between the AoS segmentations obtained with different software packages. No variable was significantly different between software packages, with the exception of Vmean diastolic peak and CSA. Vmax diastolic peak differentiated groups, regardless of the software package. In conclusion, a clinical study should preliminarily evaluate the repeatability in order to interpret its findings. Vmax seemed to be a repeatable and reproducible measure, since the pixel with its value is usually located in the center of the AoS, and is thus unlikely be affected by ROI size.
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Affiliation(s)
| | - Dejan Jakimovski
- Buffalo Neuroimaging Analysis Center (BNAC), Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; (D.J.); (M.G.D.); (R.Z.)
| | - Niels Bergsland
- IRCCS, Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy; (N.B.); (F.B.)
- Buffalo Neuroimaging Analysis Center (BNAC), Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; (D.J.); (M.G.D.); (R.Z.)
| | - Michael G. Dwyer
- Buffalo Neuroimaging Analysis Center (BNAC), Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; (D.J.); (M.G.D.); (R.Z.)
| | - Francesca Baglio
- IRCCS, Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy; (N.B.); (F.B.)
| | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center (BNAC), Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, USA; (D.J.); (M.G.D.); (R.Z.)
- Center for Biomedical Imaging at Clinical Translational Science Institute, University at Buffalo, State University of New York, Buffalo, NY 14203, USA
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21
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Morgan AG, Thrippleton MJ, Wardlaw JM, Marshall I. 4D flow MRI for non-invasive measurement of blood flow in the brain: A systematic review. J Cereb Blood Flow Metab 2021; 41:206-218. [PMID: 32936731 PMCID: PMC8369999 DOI: 10.1177/0271678x20952014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/22/2020] [Accepted: 07/05/2020] [Indexed: 01/25/2023]
Abstract
The brain's vasculature is essential for brain health and its dysfunction contributes to the onset and development of many dementias and neurological disorders. While numerous in vivo imaging techniques exist to investigate cerebral haemodynamics in humans, phase-contrast magnetic resonance imaging (MRI) has emerged as a reliable, non-invasive method of quantifying blood flow within intracranial vessels. In recent years, an advanced form of this method, known as 4D flow, has been developed and utilised in patient studies, where its ability to capture complex blood flow dynamics within any major vessel across the acquired volume has proved effective in collecting large amounts of information in a single scan. While extremely promising as a method of examining the vascular system's role in brain-related diseases, the collection of 4D data can be time-consuming, meaning data quality has to be traded off against the acquisition time. Here, we review the available literature to examine 4D flow's capabilities in assessing physiological and pathological features of the cerebrovascular system. Emerging techniques such as dynamic velocity-encoding and advanced undersampling methods, combined with increasingly high-field MRI scanners, are likely to bring 4D flow to the forefront of cerebrovascular imaging studies in the years to come.
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Affiliation(s)
- Alasdair G Morgan
- Brain Research Imaging Centre, Centre for Clinical Brain
Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute at The University of Edinburgh,
Edinburgh Medical School, Edinburgh, UK
| | - Michael J Thrippleton
- Brain Research Imaging Centre, Centre for Clinical Brain
Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute at The University of Edinburgh,
Edinburgh Medical School, Edinburgh, UK
| | - Joanna M Wardlaw
- Brain Research Imaging Centre, Centre for Clinical Brain
Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute at The University of Edinburgh,
Edinburgh Medical School, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology,
University of Edinburgh, Edinburgh, UK
| | - Ian Marshall
- Brain Research Imaging Centre, Centre for Clinical Brain
Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute at The University of Edinburgh,
Edinburgh Medical School, Edinburgh, UK
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22
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Vikner T, Nyberg L, Holmgren M, Malm J, Eklund A, Wåhlin A. Characterizing pulsatility in distal cerebral arteries using 4D flow MRI. J Cereb Blood Flow Metab 2020; 40:2429-2440. [PMID: 31722598 PMCID: PMC7820688 DOI: 10.1177/0271678x19886667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood-brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a method based on four-dimensional (4D) flow MRI to estimate a global composite flow waveform of distal cerebral arteries. The method is based on finding and sampling arterial waveforms from thousands of cross sections in numerous small vessels of the brain, originating from cerebral cortical arteries. We demonstrate agreement with internal and external reference methods and show the ability to capture significant increases in distal cerebral arterial pulsatility as a function of age. The proposed approach can be used to advance our understanding regarding excessive arterial pulsatility as a potential trigger of cognitive decline and dementia.
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Affiliation(s)
- Tomas Vikner
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Tomas Vikner, Department of Radiation Sciences, Umeå University, Umeå SE 901 87, Sweden.
| | - Lars Nyberg
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
- Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | | | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
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23
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van Tuijl RJ, Ruigrok YM, Velthuis BK, van der Schaaf IC, Rinkel GJE, Zwanenburg JJM. Velocity Pulsatility and Arterial Distensibility Along the Internal Carotid Artery. J Am Heart Assoc 2020; 9:e016883. [PMID: 32783485 PMCID: PMC7660833 DOI: 10.1161/jaha.120.016883] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Attenuation of velocity pulsatility along the internal carotid artery (ICA) is deemed necessary to protect the microvasculature of the brain. The role of the carotid siphon within the whole ICA trajectory in pulsatility attenuation is still poorly understood. This study aims to assess arterial variances in velocity pulsatility and distensibility over the whole ICA trajectory, including effects of age and sex. Methods and Results We assessed arterial velocity pulsatility and distensibility using flow-sensitized 2-dimensional phase-contrast 3.0 Tesla magnetic resonance imaging in 118 healthy participants. Velocity pulsatility index (vPI=(Vmax-Vmin)/Vmean) and arterial distensibility defined as area pulsatility index (Amax-Amin)/Amean) were calculated at C1, C3, and C7 segments of the ICA. vPI increased between C1 and C3 (0.85±0.13 versus 0.93±0.13, P<0.001 for averaged right+left ICA) and decreased between C3 and C7 (0.93±0.13 versus 0.84±0.13, P<0.001) with overall no effect (C1-C7). Conversely, the area pulsatility index decreased between C1 and C3 (0.18±0.06 versus 0.14±0.04, P<0.001) and increased between C3 and C7 (0.14±0.04 versus 0.31±0.09, P<0.001). vPI in men is higher than in women and increases with age (P<0.015). vPI over the carotid siphon declined with age but remained stable over the whole ICA trajectory. Conclusions Along the whole ICA trajectory, vPI increased from extracranial C1 up to the carotid siphon C3 with overall no effect on vPI between extracranial C1 and intracranial C7 segments. This suggests that the bony carotid canal locally limits the arterial distensibility of the ICA, increasing the vPI at C3 which is consequently decreased again over the carotid siphon. In addition, vPI in men is higher and increases with age.
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Affiliation(s)
- Rick J van Tuijl
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
| | - Ynte M Ruigrok
- Department of Neurology and Neurosurgery Rudolf Magnus Institute of Neuroscience University Medical Center Utrecht Utrecht The Netherlands
| | - Birgitta K Velthuis
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
| | | | - Gabriël J E Rinkel
- Department of Neurology and Neurosurgery Rudolf Magnus Institute of Neuroscience University Medical Center Utrecht Utrecht The Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology University Medical Center Utrecht Utrecht The Netherlands
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24
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Multiparametric flow analysis using four-dimensional flow magnetic resonance imaging can detect cerebral hemodynamic impairment in patients with internal carotid artery stenosis. Neuroradiology 2020; 62:1421-1431. [PMID: 32518970 DOI: 10.1007/s00234-020-02464-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 05/21/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE MRI-based risk stratification should be established to identify patients with internal carotid artery stenosis (ICS) who require further PET or SPECT evaluation. This study assessed whether multiparametric flow analysis using time-resolved 3D phase-contrast (4D flow) MRI can detect cerebral hemodynamic impairment in patients with ICS. METHODS This retrospective study analyzed 26 consecutive patients with unilateral ICS (21 men; mean age, 71 years) who underwent 4D flow MRI and acetazolamide-stress brain perfusion SPECT. Collateral flow via the Willis ring was visually evaluated. Temporal mean flow volume rate (Net), pulsatile flow volume (ΔV), and pulsatility index (PI) at the middle cerebral artery were measured. Cerebral vascular reserve (CVR) was calculated from the SPECT dataset. Patients were assigned to the misery perfusion group if the CVR was < 10% and to the nonmisery perfusion group if the CVR was ≥ 10%. Parameters showing a significant difference in both groups were statistically evaluated. RESULTS Affected side ΔV, ratio of affected to contralateral side Net (rNet), and ratio of affected to contralateral side ΔV were significantly correlated to CVR (p = 0.030, p = 0.010, p = 0.015, respectively). Absence of retrograde flow at the posterior communicating artery was observed in the misery perfusion group (p = 0.020). Combined cut-off values of the affected side ΔV (0.18 ml) and rNet (0.64) showed a sensitivity and specificity of 100% and 77.8%, respectively. CONCLUSION Multiparametric flow analysis using 4D flow MRI can detect misery perfusion by comprehensively assessing blood flow data, including blood flow volume, pulsation, and collateral flow.
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25
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Fold-Over Oversampling Effects in the Measurements of Cerebral Cerebrospinal Fluid and Blood Flows with 2D Cine Phase-Contrast MRI. Diagnostics (Basel) 2020; 10:diagnostics10060387. [PMID: 32526946 PMCID: PMC7345509 DOI: 10.3390/diagnostics10060387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 11/16/2022] Open
Abstract
This prospective study investigated the effects of fold-over oversampling on phase-offset background errors with 2D-Cine phase contrast (Cine-PC) magnetic resonance imaging (MRI). It was performed on brain MRI and compared to conventional Full-field of view FOV coverage and it was tested with two different velocity encoding (Venc) values. We chose Venc = 100 mm/s to encode cerebrospinal fluid (CSF) flows in the aqueduct and 600 mm/s to encode blood flow in the carotid artery. Cine-PC was carried out on 10 healthy adult volunteers followed simultaneously by an acquisition on static agar-gel phantom to measure the phase-offset background errors. Pixel-wise correction of both the CSF and the blood flows was calculated through 32 points of the cardiac-cycle. We compared the velocity-to-noise ratio, the section area, the absolute and the corrected velocity (peak; mean and minimum), the net flow, and the stroke volume before and after correction. We performed the statistical T-test to compare Full-FOV and fold-over and Bland–Altman plots to analyze their differences. Our results showed that following phase-offset error correction, the blood stroke-volume was significantly higher with Full-FOV compared to fold-over. We observed a significantly higher CSF mean velocity and net flow values in the fold-over option. Compared to Full-FOV, fold-over provides a significantly larger section area and significantly lower peak velocity-offset in the aqueduct. No significant difference between the two coverages was reported before and after phase-offset in blood flow measurements. In conclusion, fold-over oversampling can be chosen as an alternative to increase spatial resolution and accurate cerebral flow quantification in Cine-PC.
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26
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27
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van der Kleij LA, De Vis JB, de Bresser J, Hendrikse J, Siero JCW. Arterial CO 2 pressure changes during hypercapnia are associated with changes in brain parenchymal volume. Eur Radiol Exp 2020; 4:17. [PMID: 32147754 PMCID: PMC7061094 DOI: 10.1186/s41747-020-0144-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 01/23/2020] [Indexed: 11/10/2022] Open
Abstract
The Monro-Kellie hypothesis (MKH) states that volume changes in any intracranial component (blood, brain tissue, cerebrospinal fluid) should be counterbalanced by a co-occurring opposite change to maintain intracranial pressure within the fixed volume of the cranium. In this feasibility study, we investigate the MKH application to structural magnetic resonance imaging (MRI) in observing compensating intracranial volume changes during hypercapnia, which causes an increase in cerebral blood volume. Seven healthy subjects aged from 24 to 64 years (median 32), 4 males and 3 females, underwent a 3-T three-dimensional T1-weighted MRI under normocapnia and under hypercapnia. Intracranial tissue volumes were computed. According to the MKH, the significant increase in measured brain parenchymal volume (median 6.0 mL; interquartile range 4.5, 8.5; p = 0.016) during hypercapnia co-occurred with a decrease in intracranial cerebrospinal fluid (median -10.0 mL; interquartile range -13.5, -6.5; p = 0.034). These results convey several implications: (i) blood volume changes either caused by disorders, anaesthesia, or medication can affect outcome of brain volumetric studies; (ii) besides probing tissue displacement, this approach may assess the brain cerebrovascular reactivity. Future studies should explore the use of alternative sequences, such as three-dimensional T2-weighted imaging, for improved quantification of hypercapnia-induced volume changes.
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Affiliation(s)
- Lisa A van der Kleij
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3508 GA, Utrecht, The Netherlands.
| | - Jill B De Vis
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jeroen de Bresser
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3508 GA, Utrecht, The Netherlands
| | - Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3508 GA, Utrecht, The Netherlands
- Spinoza Center for Neuroimaging, Amsterdam, The Netherlands
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28
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Chatterjee K, Carman-Esparza CM, Munson JM. Methods to measure, model and manipulate fluid flow in brain. J Neurosci Methods 2020; 333:108541. [PMID: 31838183 PMCID: PMC7607555 DOI: 10.1016/j.jneumeth.2019.108541] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/01/2019] [Accepted: 12/04/2019] [Indexed: 01/15/2023]
Abstract
The brain consists of a complex network of cells and matrix that is cushioned and nourished by multiple types of fluids: cerebrospinal fluid, blood, and interstitial fluid. The movement of these fluids through the tissues has recently gained more attention due to implications in Alzheimer's Disease and glioblastoma. Therefore, methods to study these fluid flows are necessary and timely for the current study of neuroscience. Imaging modalities such as magnetic resonance imaging have been used clinically and pre-clinically to image flows in healthy and diseased brains. These measurements have been used to both parameterize and validate models of fluid flow both computational and in vitro. Both of these models can elucidate the changes to fluid flow that occur during disease and can assist in linking the compartments of fluid flow with one another, a difficult challenge experimentally. In vitro models, though in limited use with fluid flow, allow the examination of cellular responses to physiological flow. To determine causation, in vivo methods have been developed to manipulate flow, including both physical and pharmacological manipulations, at each point of fluid movement of origination resulting in exciting findings in the preclinical setting. With new targets, such as the brain-draining lymphatics and glymphatic system, fluid flow and tissue drainage within the brain is an exciting and growing research area. In this review, we discuss the methods that currently exist to examine and test hypotheses related to fluid flow in the brain as we attempt to determine its impact on neural function.
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Affiliation(s)
- Krishnashis Chatterjee
- Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Cora M Carman-Esparza
- Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jennifer M Munson
- Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States.
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29
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Zarrinkoob L, Wåhlin A, Ambarki K, Birgander R, Eklund A, Malm J. Blood Flow Lateralization and Collateral Compensatory Mechanisms in Patients With Carotid Artery Stenosis. Stroke 2020; 50:1081-1088. [PMID: 30943887 PMCID: PMC6485302 DOI: 10.1161/strokeaha.119.024757] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Background and Purpose- Four-dimensional phase-contrast magnetic resonance imaging enables quantification of blood flow rate (BFR; mL/min) in multiple cerebral arteries simultaneously, making it a promising technique for hemodynamic investigation in patients with stroke. The aim of this study was to quantify the hemodynamic disturbance and the compensatory pattern of collateral flow in patients with symptomatic carotid stenosis. Methods- Thirty-eight patients (mean, 72 years; 27 men) with symptomatic carotid stenosis (≥50%) or occlusion were investigated using 4-dimensional phase-contrast magnetic resonance imaging. For each patient, BFR was measured in 19 arteries/locations. The ipsilateral side to the symptomatic carotid stenosis was compared with the contralateral side. Results- Internal carotid artery BFR was lower on the ipsilateral side (134±87 versus 261±95 mL/min; P<0.001). BFR in anterior cerebral artery (A1 segment) was lower on ipsilateral side (35±58 versus 119±72 mL/min; P<0.001). Anterior cerebral artery territory bilaterally was primarily supplied by contralateral internal carotid artery. The ipsilateral internal carotid artery mainly supplied the ipsilateral middle cerebral artery (MCA) territory. MCA was also supplied by a reversed BFR found in the ophthalmic and the posterior communicating artery routes on the ipsilateral side (-5±28 versus 10±28 mL/min, P=0.001, and -2±12 versus 6±6 mL/min, P=0.03, respectively). Despite these compensations, BFR in MCA was lower on the ipsilateral side, and this laterality was more pronounced in patients with severe carotid stenosis (≥70%). Although comparing ipsilateral MCA BFR between stenosis groups (<70% and ≥70%), there was no difference ( P=0.95). Conclusions- With a novel approach using 4-dimensional phase-contrast magnetic resonance imaging, we could simultaneously quantify and rank the importance of collateral routes in patients with carotid stenosis. An important observation was that contralateral internal carotid artery mainly secured the bilateral anterior cerebral artery territory. Because of the collateral recruitment, compromised BFR in MCA is not necessarily related to the degree of carotid stenosis. These findings highlight the importance of simultaneous investigation of the hemodynamics of the entire cerebral arterial tree.
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Affiliation(s)
- Laleh Zarrinkoob
- From the Department of Pharmacology and Clinical Neuroscience, Umeå, Sweden (L.Z., J.M.).,Department of Surgical and Perioperative Sciences, Umeå, Sweden (L.Z.)
| | - Anders Wåhlin
- Department of Radiation Science, Umeå, Sweden (A.W., K.A., R.B., A.E.).,Centre for Biomedical Engineering and Physics, Umeå, Sweden (A.W., K.A., A.E.).,Umeå Center for Functional Brain Imaging, Sweden (A.W., A.E.)
| | - Khalid Ambarki
- Department of Radiation Science, Umeå, Sweden (A.W., K.A., R.B., A.E.).,Centre for Biomedical Engineering and Physics, Umeå, Sweden (A.W., K.A., A.E.)
| | - Richard Birgander
- Department of Radiation Science, Umeå, Sweden (A.W., K.A., R.B., A.E.)
| | - Anders Eklund
- Department of Radiation Science, Umeå, Sweden (A.W., K.A., R.B., A.E.).,Centre for Biomedical Engineering and Physics, Umeå, Sweden (A.W., K.A., A.E.).,Umeå Center for Functional Brain Imaging, Sweden (A.W., A.E.)
| | - Jan Malm
- From the Department of Pharmacology and Clinical Neuroscience, Umeå, Sweden (L.Z., J.M.)
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30
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Holmlund P, Qvarlander S, Malm J, Eklund A. Can pulsatile CSF flow across the cerebral aqueduct cause ventriculomegaly? A prospective study of patients with communicating hydrocephalus. Fluids Barriers CNS 2019; 16:40. [PMID: 31865917 PMCID: PMC6927212 DOI: 10.1186/s12987-019-0159-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/05/2019] [Indexed: 11/26/2022] Open
Abstract
Background Communicating hydrocephalus is a disease where the cerebral ventricles are enlarged. It is characterized by the absence of detectable cerebrospinal fluid (CSF) outflow obstructions and often with increased CSF pulsatility measured in the cerebral aqueduct (CA). We hypothesize that the cardiac-related pulsatile flow over the CA, with fast systolic outflow and slow diastolic inflow, can generate net pressure effects that could source the ventriculomegaly in these patients. This would require a non-zero cardiac cycle averaged net pressure difference (ΔPnet) over the CA, with higher average pressure in the lateral and third ventricles. Methods We tested the hypothesis by calculating ΔPnet across the CA using computational fluid dynamics based on prospectively collected high-resolution structural (FIESTA-C, resolution 0.39 × 0.39 × 0.3 mm3) and velocimetric (2D-PCMRI, in-plane resolution 0.35 × 0.35 mm2) MRI-data from 30 patients investigated for communicating hydrocephalus. Results The ΔPnet due to CSF pulsations was non-zero for the study group (p = 0.03) with a magnitude of 0.2 ± 0.4 Pa (0.001 ± 0.003 mmHg), with higher pressure in the third ventricle. The maximum pressure difference over the cardiac cycle ΔPmax was 20.3 ± 11.8 Pa and occurred during systole. A generalized linear model verified an association between ΔPnet and CA cross-sectional area (p = 0.01) and flow asymmetry, described by the ratio of maximum inflow/outflow (p = 0.04), but not for aqueductal stroke volume (p = 0.35). Conclusions The results supported the hypothesis with respect to the direction of ΔPnet, although the magnitude was low. Thus, although the pulsations may generate a pressure difference across the CA it is likely too small to explain the ventriculomegaly in communicating hydrocephalus.
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Affiliation(s)
- P Holmlund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.
| | - S Qvarlander
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - J Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - A Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Centre for Functional Brain Imaging, Umeå University, Umeå, Sweden
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31
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Adams AL, Viergever MA, Luijten PR, Zwanenburg JJM. Validating faster DENSE measurements of cardiac-induced brain tissue expansion as a potential tool for investigating cerebral microvascular pulsations. Neuroimage 2019; 208:116466. [PMID: 31843712 DOI: 10.1016/j.neuroimage.2019.116466] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 12/13/2019] [Indexed: 11/17/2022] Open
Abstract
Displacement Encoding with Stimulated Echoes (DENSE) has recently shown potential for measuring cardiac-induced cerebral volumetric strain in the human brain. As such, it may provide a powerful tool for investigating the cerebral small vessels. However, further development and validation are necessary. This study aims, first, to validate a retrospectively-gated implementation of the DENSE method for assessing brain tissue pulsations as a physiological marker, and second, to use the acquired measurements to explore intracranial volume dynamics. We acquired repeated measurements of cerebral volumetric strain in 8 healthy subjects, and internally validated these measurements by comparing them to spinal CSF stroke volumes obtained in the same scan session. Peak volumetric strain was found to be highly repeatable between scan sessions. First/second measured peak volumetric strains were: (6.4 ± 1.7)x10-4/(6.7 ± 1.6)x10-4 for whole brain, (9.5 ± 2.5)x10-4/(9.6 ± 2.4)x10-4 for grey matter, and (4.4 ± 1.7)x10-4/(4.1 ± 0.8)x10-4 for white matter. Grey matter showed significantly higher peak strain (p < 0.001) and earlier time-to-peak strain (p < 0.02) than white matter. An approximately linear relationship was found between CSF and brain tissue volume pulsations over the cardiac cycle (mean slope and R2 of 0.88 ± 0.23 and 0.89 ± 0.07, respectively). The close similarity between CSF and brain tissue volume pulsations implies limited contributions from large intracranial vessel pulsations, providing further evidence for venous compression as an additional mechanism for maintaining stable intracranial pressures over the cardiac cycle. Cerebral pulsatility showed consistent inter-subject peak values in healthy subjects, and was strongly correlated to CSF stroke volumes. These results strengthen the potential of brain tissue volumetric strain as a means for investigating the intracranial dynamics of the ageing brain in normal or diseased states.
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Affiliation(s)
- Ayodeji L Adams
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Max A Viergever
- Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, E 01.132, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
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32
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Birnefeld J, Wåhlin A, Eklund A, Malm J. Cerebral arterial pulsatility is associated with features of small vessel disease in patients with acute stroke and TIA: a 4D flow MRI study. J Neurol 2019; 267:721-730. [PMID: 31728712 PMCID: PMC7035303 DOI: 10.1007/s00415-019-09620-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/30/2019] [Accepted: 11/02/2019] [Indexed: 11/16/2022]
Abstract
Cerebral small vessel disease (SVD) is a major cause of stroke and cognitive impairment. However, the underlying mechanisms behind SVD are still poorly understood. High cerebral arterial pulsatility has been suggested as a possible cause of SVD. In population studies, arterial pulsatility has been linked to white matter hyperintensities (WMH), cerebral atrophy, and cognitive impairment, all features of SVD. In stroke, pulsatility data are scarce and contradictory. The aim of this study was to investigate the relationship between arterial pulsatility and SVD in stroke patients. With a cross-sectional design, 89 patients with acute ischemic stroke or TIA were examined with MRI. A neuropsychological assessment was performed 1 year later. Using 4D flow MRI, pulsatile indices (PI) were calculated for the internal carotid artery (ICA) and middle cerebral artery (M1, M3). Flow volume pulsatility (FVP), a measure corresponding to the cyclic expansion of the arterial tree, was calculated for the same locations. These parameters were assessed for associations with WMH volume, brain volume and cognitive function. ICA-FVP was associated with WMH volume (β = 1.67, 95% CI: [0.1, 3.24], p = 0.037). M1-PI and M1-FVP were associated with decreasing cognitive function (β = − 4.4, 95% CI: [− 7.7, − 1.1], p = 0.009 and β = − 13.15, 95% CI: [− 24.26, − 2.04], p = 0.02 respectively). In summary, this supports an association between arterial pulsatility and SVD in stroke patients, and provides a potential target for further research and preventative treatment. FVP may become a useful biomarker for assessing pulsatile stress with PCMRI and 4D flow MRI.
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Affiliation(s)
- Johan Birnefeld
- Department of Pharmacology and Clinical Neuroscience, Umeå University, 90187, Umeå, Sweden.
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Centre for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, 90187, Umeå, Sweden
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Seymour RS, Bosiocic V, Snelling EP, Chikezie PC, Hu Q, Nelson TJ, Zipfel B, Miller CV. Cerebral blood flow rates in recent great apes are greater than in Australopithecus species that had equal or larger brains. Proc Biol Sci 2019; 286:20192208. [PMID: 31718497 DOI: 10.1098/rspb.2019.2208] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Brain metabolic rate (MR) is linked mainly to the cost of synaptic activity, so may be a better correlate of cognitive ability than brain size alone. Among primates, the sizes of arterial foramina in recent and fossil skulls can be used to evaluate brain blood flow rate, which is proportional to brain MR. We use this approach to calculate flow rate in the internal carotid arteries (Q˙ICA), which supply most of the primate cerebrum. Q˙ICA is up to two times higher in recent gorillas, chimpanzees and orangutans compared with 3-million-year-old australopithecine human relatives, which had equal or larger brains. The scaling relationships between Q˙ICA and brain volume (Vbr) show exponents of 1.03 across 44 species of living haplorhine primates and 1.41 across 12 species of fossil hominins. Thus, the evolutionary trajectory for brain perfusion is much steeper among ancestral hominins than would be predicted from living primates. Between 4.4-million-year-old Ardipithecus and Homo sapiens, Vbr increased 4.7-fold, but Q˙ICA increased 9.3-fold, indicating an approximate doubling of metabolic intensity of brain tissue. By contrast, Q˙ICA is proportional to Vbr among haplorhine primates, suggesting a constant volume-specific brain MR.
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Affiliation(s)
- Roger S Seymour
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Vanya Bosiocic
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Edward P Snelling
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.,Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Prince C Chikezie
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Qiaohui Hu
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Thomas J Nelson
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Bernhard Zipfel
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Case V Miller
- Vertebrate Palaeontology Laboratory, Department of Earth Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
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Holmgren M, Wåhlin A, Dunås T, Malm J, Eklund A. Assessment of Cerebral Blood Flow Pulsatility and Cerebral Arterial Compliance With 4D Flow MRI. J Magn Reson Imaging 2019; 51:1516-1525. [PMID: 31713964 PMCID: PMC7216927 DOI: 10.1002/jmri.26978] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Four-dimensional flow magnetic resonance imaging (4D flow MRI) enables efficient investigation of cerebral blood flow pulsatility in the cerebral arteries. This is important for exploring hemodynamic mechanisms behind vascular diseases associated with arterial pulsations. PURPOSE To investigate the feasibility of pulsatility assessments with 4D flow MRI, its agreement with reference two-dimensional phase-contrast MRI (2D PC-MRI) measurements, and to demonstrate how 4D flow MRI can be used to assess cerebral arterial compliance and cerebrovascular resistance in major cerebral arteries. STUDY TYPE Prospective. SUBJECTS Thirty-five subjects (20 women, 79 ± 5 years, range 70-91 years). FIELD STRENGTH/SEQUENCE 4D flow MRI (PC-VIPR) and 2D PC-MRI acquired with a 3T scanner. ASSESSMENT Time-resolved flow was assessed in nine cerebral arteries. From the pulsatile flow waveform in each artery, amplitude (ΔQ), volume load (ΔV), and pulsatility index (PI) were calculated. To reduce high-frequency noise in the 4D flow MRI data, the flow waveforms were low-pass filtered. From the total cerebral blood flow, total PI (PItot ), total volume load (ΔVtot ), cerebral arterial compliance (C), and cerebrovascular resistance (R) were calculated. STATISTICAL TESTS Two-tailed paired t-test, intraclass correlation (ICC). RESULTS There was no difference in ΔQ between 4D flow MRI and the reference (0.00 ± 0.022 ml/s, mean ± SEM, P = 0.97, ICC = 0.95, n = 310) with a cutoff frequency of 1.9 Hz and 15 cut plane long arterial segments. For ΔV, the difference was -0.006 ± 0.003 ml (mean ± SEM, P = 0.07, ICC = 0.93, n = 310) without filtering. Total R was 11.4 ± 2.41 mmHg/(ml/s) (mean ± SD) and C was 0.021 ± 0.009 ml/mmHg (mean ± SD). ΔVtot was 1.21 ± 0.29 ml (mean ± SD) with an ICC of 0.82 compared with the reference. PItot was 1.08 ± 0.21 (mean ± SD). DATA CONCLUSION We successfully assessed 4D flow MRI cerebral arterial pulsatility, cerebral arterial compliance, and cerebrovascular resistance. Averaging of multiple cut planes and low-pass filtering was necessary to assess accurate peak-to-peak features in the flow rate waveforms. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1516-1525.
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Affiliation(s)
| | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Tora Dunås
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden.,Center for Demographic and Aging Research, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
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Yu E, Ashwell KWS, Shulruf B. Quantitative analysis of arterial supply to the developing brain in tetrapod vertebrates. Anat Rec (Hoboken) 2019; 303:2309-2329. [PMID: 31680454 DOI: 10.1002/ar.24317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 09/01/2019] [Accepted: 10/03/2019] [Indexed: 11/05/2022]
Abstract
Understanding the metabolic cost of building developing tetrapod brains is critically important to explaining the more than 10-fold differences in encephalization of adult tetrapods that have emerged during evolution. The exact metabolic costs of developing the variety of tetrapod brains are impossible to determine, but one can compare cerebral artery caliber (internal radius raised to the fourth power-r4 ) across developing tetrapod vertebrate groups as a proxy of cerebral arterial flow, the delivery of nutrients during embryogenesis and early postnatal development, and hence the metabolic costs of brain development. In this study, r4 of aortic outflow and cerebral inflow arteries, as well as aortic wall thickness as a proxy of arterial pressure, were measured and compared between developing representatives of all four tetrapod classes (mammals, birds, reptiles, and amphibians). We found a clear endotherm/ectotherm dichotomy in aortic outflow and cerebral inflow between developing mammals and birds on the one hand, and developing reptiles and amphibians on the other. We did not find strong evidence for functionally significant differences in cerebral arterial caliber between groups at the order level (i.e., within birds, reptiles or amphibians). In particular, we did not find evidence in favor of increased blood supply to the brain for more behaviorally complex and encephalized avian species.
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Affiliation(s)
- Eamon Yu
- Department of Anatomy, School of Medical Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Ken W S Ashwell
- Department of Anatomy, School of Medical Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Boaz Shulruf
- Medical Education, The University of New South Wales, Sydney, New South Wales, Australia
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Sartoretti T, Wyss M, Sartoretti E, Reischauer C, Hainc N, Graf N, Binkert C, Najafi A, Sartoretti-Schefer S. Sex and Age Dependencies of Aqueductal Cerebrospinal Fluid Dynamics Parameters in Healthy Subjects. Front Aging Neurosci 2019; 11:199. [PMID: 31427956 PMCID: PMC6688190 DOI: 10.3389/fnagi.2019.00199] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/16/2019] [Indexed: 11/29/2022] Open
Abstract
Objectives To assess the influence of age and sex on 10 cerebrospinal fluid (CSF) flow dynamics parameters measured with an MR phase contrast (PC) sequence within the cerebral aqueduct at the level of the intercollicular sulcus. Materials and Methods 128 healthy subjects (66 female subjects with a mean age of 52.9 years and 62 male subjects with a mean age of 51.8 years) with a normal Evans index, normal medial temporal atrophy (MTA) score, and without known disorders of the CSF circulation were included in the study. A PC MR sequence on a 3T MR scanner was used. Ten different flow parameters were analyzed using postprocessing software. Ordinal and linear regression models were calculated. Results The parameters stroke volume (sex: p < 0.001, age: p = 0.003), forward flow volume (sex: p < 0.001, age: p = 0.002), backward flow volume (sex: p < 0.001, age: p = 0.018), absolute stroke volume (sex: p < 0.001, age: p = 0.005), mean flux (sex: p < 0.001, age: p = 0.001), peak velocity (sex: p = 0.009, age: p = 0.0016), and peak pressure gradient (sex: p = 0.029, age: p = 0.028) are significantly influenced by sex and age. The parameters regurgitant fraction, stroke distance, and mean velocity are not significantly influenced by sex and age. Conclusion CSF flow dynamics parameters measured in the cerebral aqueduct are partly age and sex dependent. For establishment of reliable reference values for clinical use in future studies, the impact of sex and age should be considered and incorporated.
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Affiliation(s)
- Thomas Sartoretti
- Laboratory of Translational Nutrition Biology, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
| | - Michael Wyss
- Philips Healthcare, Zurich, Switzerland.,Department of Radiology, Cantonal Hospital Winterthur, Winterthur, Switzerland
| | | | - Carolin Reischauer
- Department of Radiology, Cantonal Hospital Winterthur, Winterthur, Switzerland.,Department of Medicine, University of Fribourg, Fribourg, Switzerland.,Department of Radiology, HFR Fribourg - Hôpital Cantonal, Fribourg, Switzerland
| | - Nicolin Hainc
- Department of Neuroradiology, University Hospital Zürich, University of Zürich, Zurich, Switzerland
| | | | - Christoph Binkert
- Department of Radiology, Cantonal Hospital Winterthur, Winterthur, Switzerland
| | - Arash Najafi
- Department of Radiology, Cantonal Hospital Winterthur, Winterthur, Switzerland
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37
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Sakhare AR, Barisano G, Pa J. Assessing test-retest reliability of phase contrast MRI for measuring cerebrospinal fluid and cerebral blood flow dynamics. Magn Reson Med 2019; 82:658-670. [PMID: 31020721 DOI: 10.1002/mrm.27752] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE Pathological states occur when cerebrospinal fluid (CSF) and cerebral blood flow (CBF) dynamics become dysregulated in the brain. Phase-contrast MRI (PC-MRI) is a noninvasive imaging technique that enables quantitative measurements of CSF and CBF flow. While studies have validated PC-MRI as an imaging technique for flow, few studies have evaluated its reliability for CSF and CBF flow parameters commonly associated with neurological disease. The purpose of this study was to evaluate test-retest reliability at the cerebral aqueduct (CA) and C2-C3 area using PC-MRI to assess the feasibility of investigating CSF and CBF flow dynamics. METHODS This study was performed on 27 cognitively normal young adults (ages 20-35 years). Flow data was acquired on a 3T Siemens Prisma using a 2D cine-PC pulse sequence. Three consecutive flow measurements were acquired at the CA and C2-C3 area. Intraclass correlation coefficient (ICC) and coefficient of variance (CV) were used to evaluate intrarater, inter-rater, and test-retest reliability. RESULTS Among the 26 flow parameters analyzed, 22 had excellent reliability (ICC > 0.80), including measurements of CSF stroke volume, flush peak, and fill peak, and 4 parameters had good reliability (ICC 0.60-0.79). 16 flow parameters had a mean CV ≤ 10%, 7 had a CV ≤ 15%, and 3 had a CV ≤ 30%. All CSF and CBF flow measurements had excellent inter-rater and intrarater reliability (ICC > 0.80). CONCLUSION This study shows that CSF and CBF flow can be reliably measured at the CA and C2-C3 area using PC-MRI, making it a promising tool for studying flow dynamics in the central nervous system.
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Affiliation(s)
- Ashwin R Sakhare
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California.,Department of Neurology, Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, California
| | - Giuseppe Barisano
- Department of Neurology, Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, California.,Neuroscience Graduate Program, University of Southern California, Los Angeles, California
| | - Judy Pa
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California.,Department of Neurology, Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, California.,Neuroscience Graduate Program, University of Southern California, Los Angeles, California
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38
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Vali A, Aristova M, Vakil P, Abdalla R, Prabhakaran S, Markl M, Ansari SA, Schnell S. Semi-automated analysis of 4D flow MRI to assess the hemodynamic impact of intracranial atherosclerotic disease. Magn Reson Med 2019; 82:749-762. [PMID: 30924197 DOI: 10.1002/mrm.27747] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 02/03/2019] [Accepted: 03/02/2019] [Indexed: 01/02/2023]
Abstract
PURPOSE This study evaluated the feasibility of using 4D flow MRI and a semi-automated analysis tool to assess the hemodynamic impact of intracranial atherosclerotic disease (ICAD). The ICAD impact was investigated by evaluating pressure drop (PD) at the atherosclerotic stenosis and changes in cerebral blood flow distribution in patients compared to healthy controls. METHODS Dual-venc 4D flow MRI was acquired in 25 healthy volunteers and 16 ICAD patients (ICA, N = 3; MCA, N = 13) with mild (<50%), moderate (50-69%), or severe (>70%) intracranial stenosis. A semi-automated analysis tool was developed to quantify velocity and flow from 4D flow MRI and to evaluate cerebral blood flow redistribution. PD at stenosis was estimated using the Bernoulli equation. The PD calculation was examined by an in vitro phantom study against flow simulations. RESULTS Flow analysis in controls indicated symmetry in blood flow rate (FR) and peak velocity (PV) between the brain hemispheres. For patients, PV in the affected hemisphere was significantly (65%) higher than the normal side (P = 0.002). However, FR to both hemispheres of the brain was the same. The PD depicted significant correlation with PV asymmetry in patients (ρ = 0.67 and P = 0.02), and it was significantly higher for severe compared to moderate stenosis (3.73 vs. 2.30 mm Hg, P = 0.02). CONCLUSION 4D flow MRI quantification enables assessment of the hemodynamic impact of ICAD. The significant difference of the PD between patients with severe and moderate stenosis and its correlation with PV asymmetry suggest that PD may be a pertinent hemodynamic biomarker to evaluate ICAD.
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Affiliation(s)
- Alireza Vali
- Department of Radiology, Northwestern University, Chicago, Illinois
| | - Maria Aristova
- Department of Radiology, Northwestern University, Chicago, Illinois.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Parmede Vakil
- Department of Radiology, Northwestern University, Chicago, Illinois.,Department of Neurological Surgery, Northwestern University, Chicago, Illinois
| | - Ramez Abdalla
- Department of Radiology, Northwestern University, Chicago, Illinois.,Department of Neurological Surgery, Northwestern University, Chicago, Illinois
| | | | - Michael Markl
- Department of Radiology, Northwestern University, Chicago, Illinois.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Sameer A Ansari
- Department of Radiology, Northwestern University, Chicago, Illinois.,Department of Neurology, Northwestern University, Chicago, Illinois.,Department of Neurological Surgery, Northwestern University, Chicago, Illinois
| | - Susanne Schnell
- Department of Radiology, Northwestern University, Chicago, Illinois
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Loecher M, Magrath P, Aliotta E, Ennis DB. Time‐optimized 4D phase contrast MRI with real‐time convex optimization of gradient waveforms and fast excitation methods. Magn Reson Med 2019; 82:213-224. [DOI: 10.1002/mrm.27716] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Michael Loecher
- Department of Radiological Sciences University of California Los Angeles California
| | - Patrick Magrath
- Department of Bioengineering University of California Los Angeles California
| | - Eric Aliotta
- Department of Biomedical Physics University of California Los Angeles California
| | - Daniel B. Ennis
- Department of Radiological Sciences University of California Los Angeles California
- Department of Bioengineering University of California Los Angeles California
- Department of Biomedical Physics University of California Los Angeles California
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40
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Adams AL, Kuijf HJ, Viergever MA, Luijten PR, Zwanenburg JJ. Quantifying cardiac-induced brain tissue expansion using DENSE. NMR IN BIOMEDICINE 2019; 32:e4050. [PMID: 30575151 PMCID: PMC6519010 DOI: 10.1002/nbm.4050] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/16/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Brain tissue undergoes viscoelastic deformation and volumetric strain as it expands over the cardiac cycle due to blood volume changes within the underlying microvasculature. Volumetric strain measurements may therefore provide insights into small vessel function and tissue viscoelastic properties. Displacement encoding via stimulated echoes (DENSE) is an MRI technique that can quantify the submillimetre displacements associated with brain tissue motion. Despite previous studies reporting brain tissue displacements using DENSE and other MRI techniques, a complete picture of brain tissue volumetric strain over the cardiac cycle has not yet been obtained. To address this need we implemented 3D cine-DENSE at 7 T and 3 T to investigate the feasibility of measuring cardiac-induced volumetric strain as a marker for small vessel blood volume changes. Volumetric strain over the entire cardiac cycle was computed for the whole brain and for grey and white matter tissue separately in six healthy human subjects. Signal-to-noise ratio (SNR) measurements were used to determine the voxel-wise volumetric strain noise. Mean peak whole brain volumetric strain at 7 T (mean ± SD) was (4.5 ± 1.0) × 10-4 (corresponding to a volume expansion of 0.48 ± 0.1 mL), which is in agreement with literature values for cerebrospinal fluid that is displaced into the spinal canal to maintain a stable intracranial pressure. The peak volumetric strain ratio of grey to white matter was 4.4 ± 2.8, reflecting blood volume and tissue stiffness differences between these tissue types. The mean peak volumetric strains of grey and white matter tissue were found to be significantly different (p < 0.001). The mean SNR at 7 T and 3 T of the DENSE measurements was 22.0 ± 7.3 and 7.0 ± 2.8 respectively, which currently limits a voxel-wise strain analysis at both field strengths. We demonstrate that tissue specific quantification of volumetric strain is feasible with DENSE. This metric holds potential for studying blood volume pulsations in the ageing brain in healthy and diseased states.
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Affiliation(s)
- Ayodeji L. Adams
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Hugo J. Kuijf
- Image Sciences InstituteUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Max A. Viergever
- Image Sciences InstituteUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Peter R. Luijten
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
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Schrauben EM, Saini BS, Darby JRT, Soo JY, Lock MC, Stirrat E, Stortz G, Sled JG, Morrison JL, Seed M, Macgowan CK. Fetal hemodynamics and cardiac streaming assessed by 4D flow cardiovascular magnetic resonance in fetal sheep. J Cardiovasc Magn Reson 2019; 21:8. [PMID: 30661506 PMCID: PMC6340188 DOI: 10.1186/s12968-018-0512-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 12/04/2018] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND To date it has not been possible to obtain a comprehensive 3D assessment of fetal hemodynamics because of the technical challenges inherent in imaging small cardiac structures, movement of the fetus during data acquisition, and the difficulty of fusing data from multiple cardiac cycles when a cardiac gating signal is absent. Here we propose the combination of volumetric velocity-sensitive cardiovascular magnetic resonance imaging ("4D flow" CMR) and a specialized animal preparation (catheters to monitor fetal heart rate, anesthesia to immobilize mother and fetus) to examine fetal sheep cardiac hemodynamics in utero. METHODS Ten pregnant Merino sheep underwent surgery to implant arterial catheters in the target fetuses. Anesthetized ewes underwent 4D flow CMR with acquisition at 3 T for fetal whole-heart coverage with 1.2-1.5 mm spatial resolution and 45-62 ms temporal resolution. Flow was measured in the heart and major vessels, and particle traces were used to visualize circulatory patterns in fetal cardiovascular shunts. Conservation of mass was used to test internal 4D flow consistency, and comparison to standard 2D phase contrast (PC) CMR was performed for validation. RESULTS Streaming of blood from the ductus venosus through the foramen ovale was visualized. Flow waveforms in the major thoracic vessels and shunts displayed normal arterial and venous patterns. Combined ventricular output (CVO) was 546 mL/min per kg, and the distribution of flows (%CVO) were comparable to values obtained using other methods. Internal 4D flow consistency across 23 measurement locations was established with differences of 14.2 ± 12.1%. Compared with 2D PC CMR, 4D flow showed a strong correlation (R2 = 0.85) but underestimated flow (bias = - 21.88 mL/min per kg, p < 0.05). CONCLUSIONS The combination of fetal surgical preparation and 4D flow CMR enables characterization and quantification of complex flow patterns in utero. Visualized streaming of blood through normal physiological shunts confirms the complex mechanism of substrate delivery to the fetal heart and brain. Besides offering insight into normal physiology, this technology has the potential to qualitatively characterize complex flow patterns in congenital heart disease phenotypes in a large animal model, which can support the development of new interventions to improve outcomes in this population.
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Affiliation(s)
| | - Brahmdeep Singh Saini
- Heart Centre, Hospital for Sick Children, Toronto, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Jack R. T. Darby
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mitchell C. Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Elaine Stirrat
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - Greg Stortz
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - John G. Sled
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Canada
| | - Christopher K. Macgowan
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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Dunås T, Holmgren M, Wåhlin A, Malm J, Eklund A. Accuracy of blood flow assessment in cerebral arteries with 4D flow MRI: Evaluation with three segmentation methods. J Magn Reson Imaging 2019; 50:511-518. [PMID: 30637846 PMCID: PMC6767555 DOI: 10.1002/jmri.26641] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 12/03/2022] Open
Abstract
Background Accelerated 4D flow MRI allows for high‐resolution velocity measurements with whole‐brain coverage. Such scans are increasingly used to calculate flow rates of individual arteries in the vascular tree, but detailed information about the accuracy and precision in relation to different postprocessing options is lacking. Purpose To evaluate and optimize three proposed segmentation methods and determine the accuracy of in vivo 4D flow MRI blood flow rate assessments in major cerebral arteries, with high‐resolution 2D PCMRI as a reference. Study Type Prospective. Subjects Thirty‐five subjects (20 women, 79 ± 5 years, range 70–91 years). Field Strength/Sequence 4D flow MRI with PC‐VIPR and 2D PCMRI acquired with a 3 T scanner. Assessment We compared blood flow rates measured with 4D flow MRI, to the reference, in nine main cerebral arteries. Lumen segmentation in the 4D flow MRI was performed with k‐means clustering using four different input datasets, and with two types of thresholding methods. The threshold was defined as a percentage of the maximum intensity value in the complex difference image. Local and global thresholding approaches were used, with evaluated thresholds from 6–26%. Statistical Tests Paired t‐test, F‐test, linear correlation (P < 0.05 was considered significant) along with intraclass correlation (ICC). Results With the thresholding methods, the lowest average flow difference was obtained for 20% local (0.02 ± 15.0 ml/min, ICC = 0.97, n = 310) or 10% global (0.08 ± 17.3 ml/min, ICC = 0.97, n = 310) thresholding with a significant lower standard deviation for local (F‐test, P = 0.01). For all clustering methods, we found a large systematic underestimation of flow compared with 2D PCMRI (16.1–22.3 ml/min). Data Conclusion A locally adapted threshold value gives a more stable result compared with a globally fixed threshold. 4D flow with the proposed segmentation method has the potential to become a useful reliable clinical tool for assessment of blood flow in the major cerebral arteries. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:511–518.
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Affiliation(s)
- Tora Dunås
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | | | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
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Markenroth Bloch K, Töger J, Ståhlberg F. Investigation of cerebrospinal fluid flow in the cerebral aqueduct using high-resolution phase contrast measurements at 7T MRI. Acta Radiol 2018; 59:988-996. [PMID: 29141450 DOI: 10.1177/0284185117740762] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background The cerebral aqueduct is a central conduit for cerebrospinal fluid (CSF), and non-invasive quantification of CSF flow in the aqueduct may be an important tool for diagnosis and follow-up of treatment. Magnetic resonance (MR) methods at clinical field strengths are limited by low spatial resolution. Purpose To investigate the feasibility of high-resolution through-plane MR flow measurements (2D-PC) in the cerebral aqueduct at high field strength (7T). Material and Methods 2D-PC measurements in the aqueduct were performed in nine healthy individuals at 7T. Measurement accuracy was determined using a phantom. Aqueduct area, mean velocity, maximum velocity, minimum velocity, net flow, and mean flow were determined using in-plane resolutions 0.8 × 0.8, 0.5 × 0.5, 0.3 × 0.3, and 0.2 × 0.2 mm2. Feasibility criteria were defined based on scan time and spatial and temporal resolution. Results Phantom validation of 2D-PC MR showed good accuracy. In vivo, stroke volume was -8.2 ± 4.4, -4.7 ± 2.8, -6.0 ± 3.8, and -3.7 ± 2.1 µL for 0.8 × 0.8, 0.5 × 0.5, 0.3 × 0.3, and 0.2 × 0.2 mm2, respectively. The scan with 0.3 × 0.3 mm2 resolution fulfilled the feasibility criteria for a wide range of heart rates and aqueduct diameters. Conclusion 7T MR enables non-invasive quantification of CSF flow and velocity in the cerebral aqueduct with high spatial resolution.
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Affiliation(s)
| | - Johannes Töger
- Department of Diagnostic Radiology, Lund University, Skåne University Hospital, Lund, Sweden
| | - Freddy Ståhlberg
- Department of Diagnostic Radiology, Lund University, Skåne University Hospital, Lund, Sweden
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
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Seymour RS, Snelling EP. Calculating brain perfusion of primates. J Hum Evol 2018; 128:99-102. [PMID: 29983157 DOI: 10.1016/j.jhevol.2018.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/01/2018] [Accepted: 06/01/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Roger S Seymour
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Edward P Snelling
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng 2193, South Africa
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Orita E, Murai Y, Sekine T, Takagi R, Amano Y, Ando T, Iwata K, Obara M, Kumita S. Four-Dimensional Flow MRI Analysis of Cerebral Blood Flow Before and After High-Flow Extracranial–Intracranial Bypass Surgery With Internal Carotid Artery Ligation. Neurosurgery 2018; 85:58-64. [DOI: 10.1093/neuros/nyy192] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 04/13/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Erika Orita
- Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Yasuo Murai
- Depar-tment of Neurological Surgery, Nippon Medical School, Tokyo, Japan
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Ryo Takagi
- Department of Radiology, Nippon Medical School, Tokyo, Japan
- Department of Radiology, Nihon University School of Medicine, Tokyo, Japan
| | - Yasuo Amano
- Department of Radiology, Nippon Medical School, Tokyo, Japan
- Department of Radiology, Nihon University School of Medicine, Tokyo, Japan
| | - Takahiro Ando
- Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Kotomi Iwata
- Department of Radiology, Nippon Medical School, Tokyo, Japan
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Spijkerman JM, Geurts LJ, Siero JCW, Hendrikse J, Luijten PR, Zwanenburg JJM. Phase contrast MRI measurements of net cerebrospinal fluid flow through the cerebral aqueduct are confounded by respiration. J Magn Reson Imaging 2018; 49:433-444. [PMID: 29741818 PMCID: PMC6519345 DOI: 10.1002/jmri.26181] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/19/2018] [Indexed: 11/15/2022] Open
Abstract
Background Net cerebrospinal fluid (CSF) flow through the cerebral aqueduct may serve as a marker of CSF production in the lateral ventricles, and changes that occur with aging and in disease. Purpose To investigate the confounding influence of the respiratory cycle on net CSF flow and stroke volume measurements. Study Type Cross‐sectional study. Subjects Twelve young, healthy subjects (seven male, age range 19–39 years, average age 28.3 years). Field Strength/Sequence Phase contrast MRI (PC‐MRI) measurements were performed at 7T, with and without respiratory gating on expiration and on inspiration. All measurements were repeated. Assessment Net CSF flow and stroke volume in the aqueduct, over the cardiac cycle, was determined. Statistical Tests Repeatability was determined using the intraclass correlation coefficient (ICC) and linear regression analysis between the repeated measurements. Repeated measures analysis of variance (ANOVA) was performed to compare the measurements during inspiration/expiration/no gating. Linear regression analysis was performed between the net CSF flow difference (inspiration minus expiration) and stroke volume. Results Net CSF flow (average ± standard deviation) was 0.64 ± 0.32 mL/min (caudal) during expiration, 0.12 ± 0.49 mL/min (cranial) during inspiration, and 0.31 ± 0.18 mL/min (caudal) without respiratory gating. Respiratory gating did not affect stroke volume measurements (41 ± 18, 42 ± 19, 42 ± 19 μL/cycle for expiration, no respiratory gating and inspiration, respectively). Repeatability was best during inspiration (ICC = 0.88/0.56/–0.31 for gating on inspiration/expiration/no gating). A positive association was found between average stroke volume and net flow difference between inspiration and expiration (R = 0.678/0.605, P = 0.015/0.037 for the first/second repeated measurement). Data Conclusion Measured net CSF flow is confounded by respiration effects. Therefore, net CSF flow measurements with PC‐MRI cannot in isolation be directly linked to CSF production. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:433–444.
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Affiliation(s)
- Jolanda M Spijkerman
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Lennart J Geurts
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands.,Spinoza Center for Neuroimaging, Amsterdam, Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
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Lokossou A, Balédent O, Garnotel S, Page G, Balardy L, Czosnyka Z, Payoux P, Schmidt EA. ICP Monitoring and Phase-Contrast MRI to Investigate Intracranial Compliance. ACTA NEUROCHIRURGICA. SUPPLEMENT 2018; 126:247-253. [PMID: 29492570 DOI: 10.1007/978-3-319-65798-1_50] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE The amplitude of intracranial pressure (ICP) can be measured by ICP monitoring. Phase-contrast magnetic resonance imaging (PCMRI) can quantify blood and cerebrospinal fluid (CSF) flows. The aim of this work was to investigate intracranial compliance at rest by combining baseline ICP monitoring and PCMRI in hydrocephalus patients. MATERIALS AND METHODS ICP monitoring was performed before infusion testing to quantify ΔICP_rest at the basal condition in 33 suspected hydrocephalus patients (74 years). The day before, patients had had a PCMRI to assess total cerebral blood flow (tCBF), intracranial blood volume change (stroke volume SVblood), and cervical CSF volume change (the stroke volume CSV). Global (blood and CSF) intracranial volume change (ΔIVC) during each cardiac cycle (CC) was calculated. Finally, Compliance: C_rest = ΔIVC/ΔICP_rest was calculated. The data set was postprocessed by two operators according to blind analysis. RESULTS Bland-Altman plots showed that measurements presented no significant difference between the two operators. ΔICP_rest = 2.41 ± 1.21 mmHg, tCBF = 469.89 ± 127.54 mL/min, SVblood = 0.82 ± 0.32 mL/cc, CSV = 0.50 ± 0.22 mL/cc, ΔIVC = 0.44 ± 0.22 mL, and C_rest = 0.23 ± 0.15 mL/mmHg. There are significant relations between SVblood and CSV and also SVblood and tCBF. CONCLUSIONS During "basal" condition, the compliance amplitude of the intracranial compartment is heterogeneous in suspected hydrocephalus patients, and its value is lower than expected! This new parameter could represent new information, complementary to conventional infusion tests. We hope that this information can be applied to improve the selection of patients for shunt surgery.
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Affiliation(s)
- A Lokossou
- Research team BioFlowImage, University of Picardie Jules Verne, Amiens, France.
- Department of Medical Image Processing, University Hospital of Picardie, Amiens, France.
| | - O Balédent
- Research team BioFlowImage, University of Picardie Jules Verne, Amiens, France
- Department of Medical Image Processing, University Hospital of Picardie, Amiens, France
| | - S Garnotel
- Research team BioFlowImage, University of Picardie Jules Verne, Amiens, France
- Department of Medical Image Processing, University Hospital of Picardie, Amiens, France
| | - G Page
- Research team BioFlowImage, University of Picardie Jules Verne, Amiens, France
- Department of Medical Image Processing, University Hospital of Picardie, Amiens, France
| | - L Balardy
- Department of Geriatric, University Hospital of Toulouse, Toulouse, France
| | - Z Czosnyka
- Neurosciences Department, University of Cambridge, Cambridge, UK
| | - P Payoux
- Department of Nuclear Medicine, University Hospital of Toulouse, Toulouse, France
| | - E A Schmidt
- UMR 1214-INSERM/UPS-TONIC Toulouse Neuro-Imaging Center, Toulouse, France
- Department of Neurosurgery, University Hospital of Toulouse, Toulouse, France
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Zwanenburg JJM. Increased Rather than Decreased Small Vessel Pulsatility in Patients with Progressing Cerebral White Matter Hyperintensities. Radiology 2018; 286:363-364. [DOI: 10.1148/radiol.2017172090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jaco J. M. Zwanenburg
- Department of Radiology, E.01.132, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
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Braig M, Leupold J, Menza M, Russe M, Ko CW, Hennig J, von Elverfeldt D. Preclinical 4D-flow magnetic resonance phase contrast imaging of the murine aortic arch. PLoS One 2017; 12:e0187596. [PMID: 29117252 PMCID: PMC5678712 DOI: 10.1371/journal.pone.0187596] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 10/23/2017] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Cardiovascular diseases remain the number one death cause worldwide. Preclinical 4D flow phase contrast magnetic resonance imaging can provide substantial insights in the analysis of aortic pathophysiologies in various animal models. These insights may allow a better understanding of pathophysiologies, therapy monitoring, and can possibly be translated to humans. This study provides a framework to acquire the velocity field within the aortic arch. It analyses important flow values at different locations within the aortic arch. Imaging parameters with high temporal and spatial resolution are provided, that still allow combining this time-consuming method with other necessary imaging-protocols. METHODS A new setup was established where a prospectively gated 4D phase contrast sequence is combined with a highly sensitive cryogenic coil on a preclinical magnetic resonance scanner. The sequence was redesigned to maintain a close to steady state condition of the longitudinal magnetization and hence to overcome steady state artifacts. Imaging parameters were optimized to provide high spatial and temporal resolution. Pathline visualizations were generated from the acquired velocity data in order to display complex flow patterns. RESULTS Our setup allows data acquisition with at least two times the rate than that of previous publications based on Cartesian encoding, at an improved image quality. The "steady state" sequence reduces observed artifacts and provides uniform image intensity over the heart cycle. This made possible quantification of blood speed and wall shear stress (WSS) within the aorta and its branches. The highest velocities were observed in the ascending aorta with 137.5 ± 8 cm/s. Peak velocity values in the Brachiocephalic trunk were 57 ± 12 cm/s. Quantification showed that the peak flow occurs around 20 ms post R-wave in the ascending aorta. The highest mean axial wall shear stress was observed in the analysis plane between the left common carotid artery (LCCA) and the left subclavian artery. A stable image quality allows visualizing complex flow patterns by means of streamlines and for the first time, to the best of our knowledge, pathline visualizations from 4D flow MRI in mice. CONCLUSION The described setup allows analyzing pathophysiologies in mouse models of cardiovascular diseases in the aorta and its branches with better image quality and higher spatial and temporal resolution than previous Cartesian publications. Pathlines provide an advanced analysis of complex flow patterns in the murine aorta. An imaging protocol is provided that offers the possibility to acquire the aortic arch at sufficiently high resolution in less than one hour. This allows the combination of the flow assessment with other multifunctional imaging protocols.
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Affiliation(s)
- Moritz Braig
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
| | - Jochen Leupold
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marius Menza
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maximilian Russe
- Department of Radiology, Radiology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Cheng-Wen Ko
- Department of Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Juergen Hennig
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dominik von Elverfeldt
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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50
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Yin LK, Zheng JJ, Zhao L, Hao XZ, Zhang XX, Tian JQ, Zheng K, Yang YM. Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus. Acta Neurol Scand 2017; 136:434-439. [PMID: 28247411 DOI: 10.1111/ane.12750] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction. MATERIALS AND METHODS Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (Vpeak ), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (Vpeak-s , Vpeak-d ) and flow volume (Vols , Vold ) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups. RESULTS EI, Vpeak , SV, MinV, Vols , Vold , and Vpeak-d significantly increased in iNPH group (P<0.05). Vpeak-s of the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001). CONCLUSIONS INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients.
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Affiliation(s)
- L. K. Yin
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - J. J. Zheng
- Department of Neurosurgery; Huashan Hospital; Fudan University; Shanghai China
| | - L. Zhao
- Department of Neurosurgery; The First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - X. Z. Hao
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - X. X. Zhang
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - J. Q. Tian
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - K. Zheng
- Department of Neurosurgery; Huashan Hospital; Fudan University; Shanghai China
| | - Y. M. Yang
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
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