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Dogra S, Wang X, Gee JM, Gupta A, Veraart J, Ishida K, Qiu D, Dehkharghani S. Diaschisis Profiles in the Cerebellar Response to Hemodynamic Stimuli: Insights From Dynamic Measurement of Cerebrovascular Reactivity to Identify Occult and Transient Maxima. J Magn Reson Imaging 2023; 58:1462-1469. [PMID: 36995159 DOI: 10.1002/jmri.28648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND Crossed cerebellar diaschisis (CCD) refers to depressions in perfusion and metabolism within the cerebellar hemisphere contralateral to supratentorial disease. Prior investigation into CCD in cerebrovascular reactivity (CVR) has been limited to terminal CVR estimations (CVRend ). We recently have demonstrated the presence of unsustained CVR maxima (CVRmax ) using dynamic CVR analysis, offering a fully dynamic characterization of CVR to hemodynamic stimuli. PURPOSE To investigate CCD in CVRmax from dynamic blood oxygen level-dependent (BOLD) MRI, by comparison with conventional CVRend estimation. STUDY TYPE Retrospective. POPULATION A total of 23 patients (median age: 51 years, 10 females) with unilateral chronic steno-occlusive cerebrovascular disease, without prior knowledge of CCD status. FIELD STRENGTH/SEQUENCE A 3-T, T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and acetazolamide-augmented BOLD imaging performed with a gradient-echo echo-planar imaging (EPI) sequence. ASSESSMENT A custom denoising pipeline was used to generate BOLD-CVR time signals. CVRend was established using the last minute of the BOLD response relative to the first-minute baseline. Following classification of healthy versus diseased cerebral hemispheres, CVRmax and CVRend were calculated for bilateral cerebral and cerebellar hemispheres. Three independent observers evaluated all data for the presence of CCD. STATISTICAL TESTS Pearson correlations for comparing CVR across hemispheres, two-proportion Z-tests for comparing CCD prevalence, and Wilcoxon signed-rank tests for comparing median CVR. The level of statistical significance was set at P ≤ 0.05. RESULTS CCD-related changes were observed on both CVRend and CVRmax maps, with all CCD+ cases identifiable by inspection of either map. Diseased cerebral and contralateral cerebellar hemispheric CVR correlations in CCD+ patients were stronger when using CVRend (r = 0.728) as compared to CVRmax (r = 0.676). CVR correlations between healthy cerebral hemispheres and contralateral cerebellar hemispheres were stronger for CVRmax (r = 0.739) than for CVRend (r = 0.705). DATA CONCLUSION CCD-related alterations could be observed in CVR examinations. Conventional CVRend may underestimate CVR and could exaggerate CCD. EVIDENCE LEVEL 4. TECHNICAL EFFICACY Stage 3.
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Affiliation(s)
- Siddhant Dogra
- Department of Radiology, New York University Langone Health, New York, New York, USA
| | - Xiuyuan Wang
- Department of Radiology, Weill Cornell Medical College, New York, New York, USA
| | - James Michael Gee
- Department of Radiology, New York University Langone Health, New York, New York, USA
| | - Alejandro Gupta
- Department of Radiology, New York University Langone Health, New York, New York, USA
| | - Jelle Veraart
- Department of Radiology, New York University Langone Health, New York, New York, USA
| | - Koto Ishida
- Department of Neurology, New York University Langone Health, New York, New York, USA
| | - Deqiang Qiu
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Seena Dehkharghani
- Department of Radiology, New York University Langone Health, New York, New York, USA
- Department of Neurology, New York University Langone Health, New York, New York, USA
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Deckers PT, Siero JCW, Mensink MO, Kronenburg A, Braun KPJ, van der Zwan A, Bhogal AA. Anesthesia Depresses Cerebrovascular Reactivity to Acetazolamide in Pediatric Moyamoya Vasculopathy. J Clin Med 2023; 12:4393. [PMID: 37445429 DOI: 10.3390/jcm12134393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/14/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Measurements of cerebrovascular reactivity (CVR) are essential for treatment decisions in moyamoya vasculopathy (MMV). Since MMV patients are often young or cognitively impaired, anesthesia is commonly used to limit motion artifacts. Our aim was to investigate the effect of anesthesia on the CVR in pediatric MMV. We compared the CVR with multidelay-ASL and BOLD MRI, using acetazolamide as a vascular stimulus, in all awake and anesthesia pediatric MMV scans at our institution. Since a heterogeneity in disease and treatment influences the CVR, we focused on the (unaffected) cerebellum. Ten awake and nine anesthetized patients were included. The post-acetazolamide CBF and ASL-CVR were significantly lower in anesthesia patients (47.1 ± 15.4 vs. 61.4 ± 12.1, p = 0.04; 12.3 ± 8.4 vs. 23.7 ± 12.2 mL/100 g/min, p = 0.03, respectively). The final BOLD-CVR increase (0.39 ± 0.58 vs. 3.6 ± 1.2% BOLD-change (mean/SD), p < 0.0001), maximum slope of increase (0.0050 ± 0.0040%/s vs. 0.017 ± 0.0059%, p < 0.0001), and time to maximum BOLD-increase (~463 ± 136 and ~697 ± 144 s, p = 0.0028) were all significantly lower in the anesthesia group. We conclude that the response to acetazolamide is distinctively different between awake and anesthetized MMV patients, and we hypothesize that these findings can also apply to other diseases and methods of measuring CVR under anesthesia. Considering that treatment decisions heavily depend on CVR status, caution is warranted when assessing CVR under anesthesia.
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Affiliation(s)
- Pieter T Deckers
- Department of Neurosurgery, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Radiology and Nuclear Medicine, Meander Medisch Centrum, 3813 TZ Amersfoort, The Netherlands
| | - Jeroen C W Siero
- Department of Radiology, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands
- Spinoza Center for Neuroimaging, 1105 BK Amsterdam, The Netherlands
| | - Maarten O Mensink
- Pediatric Anesthesiology, Prinses Máxima Centrum, 3584 CS Utrecht, The Netherlands
| | - Annick Kronenburg
- Department of Neurosurgery, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Department of Neurosurgery, Haaglanden Medical Center, 2512 VA The Hague, The Netherlands
| | - Kees P J Braun
- Department of Pediatric Neurology, Wilhelmina Children's Hospital, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands
| | - Albert van der Zwan
- Department of Neurosurgery, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands
| | - Alex A Bhogal
- Department of Radiology, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands
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Ouyang F, Wang B, Wu Q, Yang Q, Meng X, Liu J, Xu Z, Lv L, Zeng X. Association of intravascular enhancement sign detected on high-resolution vessel wall imaging with ischaemic events in middle cerebral artery occlusion. Eur J Radiol 2023; 165:110922. [PMID: 37320882 DOI: 10.1016/j.ejrad.2023.110922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/24/2023] [Accepted: 06/05/2023] [Indexed: 06/17/2023]
Abstract
PURPOSE Patients with intracranial artery occlusion have high rates of ischaemic events and recurrence. Early identification of patients with high-risk factors is therefore beneficial for prevention. Here we assessed the association between the intravascular enhancement sign (IVES) on high-resolution vessel wall imaging (HR-VWI) and acute ischaemic stroke (AIS) in a population with middle cerebral artery (MCA) occlusion. METHOD We retrospectively analysed the records of 106 patients with 111 MCA occlusions, including 60 with and 51 without AIS, who had undergone HR-VWI and computed tomography angiography (CTA) examinations from November 2016 to February 2023. Numbers of IVES vessels were counted and compared to the CTA findings. Statistical analyses of demographic and medical data were also performed. RESULTS Occurrence rates and numbers of IVES vessels were significantly higher in the AIS than the non-AIS group (P < 0.05), and most vessels were detected on CTA. Numbers of vessels positively correlated with AIS occurrence (rho = 0.664; P < 0.0001). A multivariable ordinal logistic regression model adjusted for age, degree of wall enhancement, hypertension, and heart status identified the number of IVES vessels as an independent predictor for AIS (odds ratio = 1.6; 95% CI, 1.3-1.9; P < 0.0001). CONCLUSION Number of IVES vessels is an independent risk factor for AIS events, and may represent poor cerebral blood flow status and collateral compensation level. It thus provides cerebral haemodynamic information for patients with MCA occlusion for clinical use.
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Affiliation(s)
- Feng Ouyang
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Bo Wang
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Qin Wu
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Qiao Yang
- Department of Neurology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Xiangqiang Meng
- Department of Rehabilitation Medicine, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Jie Liu
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Zihe Xu
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Lianjiang Lv
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China
| | - Xianjun Zeng
- Department of Radiology, First Affiliated Hospital of Nanchang University, 330006 Nanchang, Jiangxi, China.
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Gee JM, Wang X, Dogra S, Veraart J, Ishida K, Dehkharghani S. White Matter Cerebrovascular Reactivity: Effects of Microangiopathy and Proximal Occlusions on the Dynamic BOLD Response. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.29.23290700. [PMID: 37398412 PMCID: PMC10312885 DOI: 10.1101/2023.05.29.23290700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Introduction Cerebral microangiopathy often manifests as white matter hyperintensities (WMH) on T2-weighted MR images and is associated with elevated stroke risk. Large vessel steno-occlusive disease (SOD) is also independently associated with stroke risk, however, the interaction of microangiopathy and SOD is not well understood. Cerebrovascular reactivity (CVR) describes the capacity of cerebral circulation to adapt to changes in perfusion pressure and neurovascular demand, and its impairment portends future infarctions. CVR can be measured with blood oxygen level dependent (BOLD) imaging following acetazolamide stimulus (ACZ-BOLD). We studied CVR differences between WMH and normal-appearing white matter (NAWM) in patients with chronic SOD, hypothesizing additive influences upon CVR measured by novel, fully dynamic CVR maxima ( CVR max ). Methods A cross sectional study was conducted to measure per-voxel, per-TR maximal CVR ( CVR max ) using a custom computational pipeline in 23 subjects with angiographically-proven unilateral SOD. WMH and NAWM masks were applied to CVR max maps. White matter was subclassified with respect to the SOD-affected hemisphere, including: i. contralateral NAWM; ii. contralateral WMH iii. ipsilateral NAWM; iv. ipsilateral WMH. CVR max was compared between these groups with a Kruskal-Wallis test followed by a Dunn-Sidak post-hoc test for multiple comparisons. Results 19 subjects (age 50±12 years, 53% female) undergoing 25 examinations met criteria. WMH volume was asymmetric in 16/19 subjects with 13/16 exhibiting higher volumes ipsilateral to SOD. Pairwise comparisons of CVR max between groups was significant with ipsilateral WMH CVR max lower than contralateral NAWM (p=0.015) and contralateral WMH (p=0.003) when comparing in-subject medians and lower than all groups when comparing pooled voxelwise values across all subjects (p<0.0001). No significant relationship between WMH lesion size and CVR max was detected. Conclusion Our results suggest additive effects of microvascular and macrovascular disease upon white matter CVR, but with greater overall effects relating to macrovascular SOD than to apparent microangiopathy. Dynamic ACZ-BOLD presents a promising path towards a quantitative stroke risk imaging biomarker. BACKGROUND Cerebral white matter (WM) microangiopathy manifests as sporadic or sometimes confluent high intensity lesions in MR imaging with T2-weighting, and bears known associations with stroke, cognitive disability, depression and other neurological disorders 1-5 . Deep white matter is particularly susceptible to ischemic injury owing to the deprivation of collateral flow between penetrating arterial territories, and hence deep white matter hyperintensities (WMH) may portend future infarctions 6-8 . The pathophysiology of WMH is variable but commonly includes a cascade of microvascular lipohyalinosis and atherosclerosis together with impaired vascular endothelial and neurogliovascular integrity, leading to blood brain barrier dysfunction, interstitial fluid accumulation, and eventually tissue damage 9-14 . Independent of the microcirculation, cervical and intracranial large vessel steno-occlusive disease (SOD) often results from atheromatous disease and is associated with increased risk of stroke owing to thromboembolic phenomena, hypoperfusion, or combinations thereof 15-17 . White matter disease is more common in the affected hemisphere of patients with asymmetric or unilateral SOD, producing both macroscopic WMH detectable by routine structural MRI, as well as microstructural changes and altered structural connectivity detected by advanced diffusion microstructural imaging 18, 19 . An improved understanding of the interaction of microvascular disease (i.e., WMH) and macrovascular steno-occlusion could better inform stroke risk stratification and guide treatment strategies when coexistent. Cerebrovascular reactivity (CVR) is an autoregulatory adaptation characterized by the capacity of the cerebral circulation to respond to physiological or pharmacological vasodilatory stimuli 20-22 . CVR may be heterogeneous and varies across tissue type and pathological states 1, 16 . Alterations in CVR are associated with elevated stroke risk in SOD patients, although white matter CVR, and in particular the CVR profiles of WMH, are only sparsely studied and not fully understood 1, 23-26 . We have previously employed blood oxygen level dependent (BOLD) imaging following a hemodynamic stimulus with acetazolamide (ACZ) in order to measure CVR (i.e. ACZ-BOLD) 21, 27, 28 . Despite the emergence of ACZ-BOLD as a technique for clinical and experimental use, poor signal-to-noise characteristics of the BOLD effect have generally limited its interpretation to coarse, time-averaged assessment of the terminal ACZ response at arbitrarily prescribed delays following ACZ administration (e.g. 10-20 minutes) 29 . More recently, we have introduced a dedicated computational pipeline to overcome historically intractable signal-to-noise ratio (SNR) limitations of BOLD, enabling fully dynamic characterization of the cerebrovascular response, including identification of previously unreported, unsustained or transient CVR maxima ( CVR max ) following hemodynamic provocation 27, 30 . In this study, we compared such dynamic interrogation of true CVR maxima between WMH and normal appearing white matter (NAWM) among patients with chronic, unilateral SOD in order to quantify their interaction and to assess the hypothesized additive effects of angiographically-evident macrovascular stenoses when intersecting microangiopathic WMH.
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Dogra S, Wang X, Gupta A, Veraart J, Ishida K, Qiu D, Dehkharghani S. Acetazolamide-augmented BOLD MRI to Assess Whole-Brain Cerebrovascular Reactivity in Chronic Steno-occlusive Disease Using Principal Component Analysis. Radiology 2023; 307:e221473. [PMID: 36916889 PMCID: PMC10140639 DOI: 10.1148/radiol.221473] [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: 06/23/2022] [Revised: 01/12/2023] [Accepted: 02/10/2023] [Indexed: 03/16/2023]
Abstract
Background Exhaustion of cerebrovascular reactivity (CVR) portends increased stroke risk. Acetazolamide-augmented blood oxygenation level-dependent (BOLD) MRI has been used to estimate CVR, but low signal-to-noise conditions relegate its use to terminal CVR (CVRend) measurements that neglect dynamic features of CVR. Purpose To demonstrate comprehensive characterization of acetazolamide-augmented BOLD MRI response in chronic steno-occlusive disease using a computational framework to precondition signal time courses for dynamic whole-brain CVR analysis. Materials and Methods This study focused on retrospective analysis of consecutive patients with unilateral chronic steno-occlusive disease who underwent acetazolamide-augmented BOLD imaging for recurrent minor stroke or transient ischemic attack at an academic medical center between May 2017 and October 2020. A custom principal component analysis-based denoising pipeline was used to correct spatially varying non-signal-bearing contributions obtained by a local principal component analysis of the MRI time series. Standard voxelwise CVRend maps representing terminal responses were produced and compared with maximal CVR (CVRmax) as isolated from binned (per-repetition time) denoised BOLD time course. A linear mixed-effects model was used to compare CVRmax and CVRend in healthy and diseased hemispheres. Results A total of 23 patients (median age, 51 years; IQR, 42-61, 13 men) who underwent 32 BOLD examinations were included. Processed MRI data showed twofold improvement in signal-to-noise ratio, allowing improved isolation of dynamic characteristics in signal time course for sliding window CVRmax analysis to the level of each BOLD repetition time (approximately 2 seconds). Mean CVRmax was significantly higher than mean CVRend in diseased (5.2% vs 3.8%, P < .01) and healthy (5.5% vs 4.0%, P < .01) hemispheres. Several distinct time-signal signatures were observed, including nonresponsive; delayed/blunted; brisk; and occasionally nonmonotonic time courses with paradoxical features in normal and abnormal tissues (ie, steal and reverse-steal patterns). Conclusion A principal component analysis-based computational framework for analysis of acetazolamide-augmented BOLD imaging can be used to measure unsustained CVRmax through twofold improvements in signal-to-noise ratio. © RSNA, 2023 Supplemental material is available for this article.
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Affiliation(s)
- Siddhant Dogra
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Xiuyuan Wang
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Alejandro Gupta
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Jelle Veraart
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Koto Ishida
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Deqiang Qiu
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
| | - Seena Dehkharghani
- From the Departments of Radiology (S. Dogra, A.G., J.V., S. Dehkharghani) and Neurology (K.I., S. Dehkharghani), New York University Langone Health, 660 First Ave, New York, NY 10016; Department of Radiology, Weill Cornell Medical College, New York, NY (X.W.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (D.Q.)
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Yeh MY, Chen HS, Hou P, Kumar VA, Johnson JM, Noll KR, Prabhu SS, Ferguson SD, Schomer DF, Peng HH, Liu HL. Cerebrovascular Reactivity Mapping Using Resting-State Functional MRI in Patients With Gliomas. J Magn Reson Imaging 2022; 56:1863-1871. [PMID: 35396789 DOI: 10.1002/jmri.28194] [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: 01/10/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Recently, a data-driven regression analysis method was developed to utilize the resting-state (rs) blood oxygenation level-dependent signal for cerebrovascular reactivity (CVR) mapping (rs-CVR), which was previously optimized by comparing with the CO2 inhalation-based method in health subjects and patients with neurovascular diseases. PURPOSE To investigate the agreement of rs-CVR and the CVR mapping with breath-hold MRI (bh-CVR) in patients with gliomas. STUDY TYPE Retrospective. POPULATION Twenty-five patients (12 males, 13 females; mean age ± SD, 48 ± 13 years) with gliomas. FIELD STRENGTH/SEQUENCE Dynamic T2*-weighted gradient-echo echo-planar imaging during a breath-hold paradigm and during the rs on a 3-T scanner. ASSESSMENT rs-CVR with various frequency ranges and resting-state fluctuation amplitude (RSFA) were assessed. The agreement between each rs-based CVR measurement and bh-CVR was determined by voxel-wise correlation and Dice coefficient in the whole brain, gray matter, and the lesion region of interest (ROI). STATISTICAL TESTS Voxel-wise Pearson correlation, Dice coefficient, Fisher Z-transformation, repeated-measure analysis of variance and post hoc test with Bonferroni correction, and nonparametric repeated-measure Friedman test and post hoc test with Bonferroni correction were used. Significance was set at P < 0.05. RESULTS Compared with bh-CVR, the highest correlations were found at the frequency bands of 0.04-0.08 Hz and 0.02-0.04 Hz for rs-CVR in both whole brain and the lesion ROI. RSFA had significantly lower correlations than did rs-CVR of 0.02-0.04 Hz and a wider frequency range (0-0.1164 Hz). Significantly higher correlations and Dice coefficient were found in normal tissues than in the lesion ROI for all three methods. DATA CONCLUSION The optimal frequency ranges for rs-CVR are determined by comparing with bh-CVR in patients with gliomas. The rs-CVR method outperformed the RSFA. Significantly higher correlation and Dice coefficient between rs- and bh-CVR were found in normal tissue than in the lesion. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Mei-Yu Yeh
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Henry S Chen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Ping Hou
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Vinodh A Kumar
- Department of Neuroradiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jason M Johnson
- Department of Neuroradiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Kyle R Noll
- Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sujit S Prabhu
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sherise D Ferguson
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Donald F Schomer
- Department of Neuroradiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Hsu-Hsia Peng
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ho-Ling Liu
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Wu J, Nahab F, Allen JW, Hu R, Dehkharghani S, Qiu D. Alterations in Functional Network Topology Within Normal Hemispheres Contralateral to Anterior Circulation Steno-Occlusive Disease: A Resting-State BOLD Study. Front Neurol 2022; 13:780896. [PMID: 35392638 PMCID: PMC8980268 DOI: 10.3389/fneur.2022.780896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/21/2022] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to assess spatially remote effects of hemodynamic impairment on functional network topology contralateral to unilateral anterior circulation steno-occlusive disease (SOD) using resting-state blood oxygen level-dependent (BOLD) imaging, and to investigate the relationships between network connectivity and cerebrovascular reactivity (CVR), a measure of hemodynamic stress. Twenty patients with unilateral, chronic anterior circulation SOD and 20 age-matched healthy controls underwent resting-state BOLD imaging. Five-minute standardized baseline BOLD acquisition was followed by acetazolamide infusion to measure CVR. The BOLD baseline was used to analyze network connectivity contralateral to the diseased hemispheres of SOD patients. Compared to healthy controls, reduced network degree (z-score = −1.158 ± 1.217, P < 0.001, false discovery rate (FDR) corrected), local efficiency (z-score = −1.213 ± 1.120, P < 0.001, FDR corrected), global efficiency (z-score = −1.346 ± 1.119, P < 0.001, FDR corrected), and enhanced modularity (z-score = 1.000 ± 1.205, P = 0.002, FDR corrected) were observed in the contralateral, normal hemispheres of SOD patients. Network degree (P = 0.089, FDR corrected; P = 0.027, uncorrected) and nodal efficiency (P = 0.089, FDR corrected; P = 0.045, uncorrected) showed a trend toward a positive association with CVR. The results indicate remote abnormalities in functional connectivity contralateral to the diseased hemispheres in patients with unilateral SOD, despite the absence of macrovascular disease or demonstrable hemodynamic impairment. The clinical impact of remote functional disruptions requires dedicated investigation but may portend far reaching consequence for even putatively unilateral cerebrovascular disease.
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Affiliation(s)
- Junjie Wu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Fadi Nahab
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Jason W. Allen
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Joint Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States
| | - Ranliang Hu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Seena Dehkharghani
- Department of Radiology, New York University Langone Medical Center, New York, NY, United States
- Department of Neurology, New York University Langone Medical Center, New York, NY, United States
| | - Deqiang Qiu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Joint Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States
- *Correspondence: Deqiang Qiu
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Kobayashi M, Igarashi S, Takahashi T, Fujiwara S, Chida K, Terasaki K, Kubo Y, Ogasawara K. Optimal timing for measuring cerebral blood flow after acetazolamide administration to detect preexisting cerebral hemodynamics and metabolism in patients with bilateral major cerebral artery steno-occlusive diseases: 15O positron emission tomography studies. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2021; 11:507-518. [PMID: 35003888 PMCID: PMC8727876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/09/2021] [Indexed: 06/14/2023]
Abstract
The present study determined the optimal timing of scanning for measurement of cerebral blood flow (CBF) after acetazolamide (ACZ) administration for detection of preexisting cerebral hemodynamics and metabolism in bilateral major cerebral artery steno-occlusive diseases. Thirty three patients underwent 15O gas positron emission tomography (PET) and each parameter was obtained in the bilateral middle cerebral artery (MCA) territories. CBF was also obtained using H2 15O PET scanning performed at baseline and at 5, 15, and 30 min after ACZ administration. Relative CBF at each time point after ACZ administration to baseline CBF was calculated. For MCA territories with normal cerebral blood volume (CBV) and cerebral metabolic rate of oxygen (CMRO2), CBF continued increasing until 15 min after ACZ administration. For MCA territories with abnormally increased CBV, CBF decreased 5 min after ACZ administration. After that, CBF continued increasing until 30 min after ACZ administration. For MCA territories with abnormally decreased CMRO2, CBF did not change 5 min after ACZ administration. Ten min later, CBF increased. The accuracy to detect abnormally increased CBV was significantly greater for relative CBF5 than for relative CBF15. The accuracy to detect abnormally decreased CMRO2 was significantly greater for relative CBF5 or CBF15 than for relative CBF30. For detecting abnormally increased oxygen extraction fraction, the accuracy did not differ among each relative CBF. These findings suggested that CBF measurement at 5 min after ACZ administration is the optimal timing for detection of preexisting cerebral hemodynamics and metabolism in bilateral major cerebral artery steno-occlusive diseases.
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Affiliation(s)
- Masakazu Kobayashi
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Suguru Igarashi
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Tatsuhiko Takahashi
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Shunrou Fujiwara
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Kohei Chida
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Kazunori Terasaki
- Institute for Biomedical Sciences, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Yoshitaka Kubo
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
| | - Kuniaki Ogasawara
- Department of Neurosurgery, Iwate Medical UniversityMorioka, Iwate 028-3695, Japan
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9
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Troy AM, Cheng HM. Human microvascular reactivity: a review of vasomodulating stimuli and non-invasive imaging assessment. Physiol Meas 2021; 42. [PMID: 34325417 DOI: 10.1088/1361-6579/ac18fd] [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: 03/31/2021] [Accepted: 07/29/2021] [Indexed: 11/11/2022]
Abstract
The microvasculature serves an imperative function in regulating perfusion and nutrient exchange throughout the body, adaptively altering blood flow to preserve hemodynamic and metabolic homeostasis. Its normal functioning is vital to tissue health, whereas its dysfunction is present in many chronic conditions, including diabetes, heart disease, and cognitive decline. As microvascular dysfunction often appears early in disease progression, its detection can offer early diagnostic information. To detect microvascular dysfunction, one uses imaging to probe the microvasculature's ability to react to a stimulus, also known as microvascular reactivity (MVR). An assessment of MVR requires an integrated understanding of vascular physiology, techniques for stimulating reactivity, and available imaging methods to capture the dynamic response. Practical considerations, including compatibility between the selected stimulus and imaging approach, likewise require attention. In this review, we provide a comprehensive foundation necessary for informed imaging of MVR, with a particular focus on the challenging endeavor of assessing microvascular function in deep tissues.
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Affiliation(s)
- Aaron M Troy
- Institute of Biomedical Engineering, University of Toronto, Toronto, CANADA
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10
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Sleight E, Stringer MS, Marshall I, Wardlaw JM, Thrippleton MJ. Cerebrovascular Reactivity Measurement Using Magnetic Resonance Imaging: A Systematic Review. Front Physiol 2021; 12:643468. [PMID: 33716793 PMCID: PMC7947694 DOI: 10.3389/fphys.2021.643468] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 12/27/2022] Open
Abstract
Cerebrovascular reactivity (CVR) magnetic resonance imaging (MRI) probes cerebral haemodynamic changes in response to a vasodilatory stimulus. CVR closely relates to the health of the vasculature and is therefore a key parameter for studying cerebrovascular diseases such as stroke, small vessel disease and dementias. MRI allows in vivo measurement of CVR but several different methods have been presented in the literature, differing in pulse sequence, hardware requirements, stimulus and image processing technique. We systematically reviewed publications measuring CVR using MRI up to June 2020, identifying 235 relevant papers. We summarised the acquisition methods, experimental parameters, hardware and CVR quantification approaches used, clinical populations investigated, and corresponding summary CVR measures. CVR was investigated in many pathologies such as steno-occlusive diseases, dementia and small vessel disease and is generally lower in patients than in healthy controls. Blood oxygen level dependent (BOLD) acquisitions with fixed inspired CO2 gas or end-tidal CO2 forcing stimulus are the most commonly used methods. General linear modelling of the MRI signal with end-tidal CO2 as the regressor is the most frequently used method to compute CVR. Our survey of CVR measurement approaches and applications will help researchers to identify good practice and provide objective information to inform the development of future consensus recommendations.
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Affiliation(s)
- Emilie Sleight
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Michael S. Stringer
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom,*Correspondence: Michael S. Stringer
| | - Ian Marshall
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Joanna M. Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Michael J. Thrippleton
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
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11
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Fujimoto K, Uwano I, Sasaki M, Oshida S, Tsutsui S, Yanagihara W, Fujiwara S, Kobayashi M, Kubo Y, Yoshida K, Terasaki K, Ogasawara K. Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET. AJNR Am J Neuroradiol 2020; 41:785-791. [PMID: 32299799 DOI: 10.3174/ajnr.a6508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/01/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Dynamic changes in cerebrovascular reactivity after acetazolamide administration vary markedly among patients with major cerebral arterial steno-occlusive disease. MR quantitative susceptibility mapping can dynamically quantify the cerebral magnetic susceptibility. The purpose of this study was to determine whether dynamic changes in susceptibility after administration of acetazolamide on 7T quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in the cerebral hemispheres with major cerebral arterial steno-occlusive disease. MATERIALS AND METHODS Sixty-five patients underwent 7T MR imaging at baseline and at 5, 10, 15, and 20 minutes after acetazolamide administration. Differences between the susceptibility of venous structures and surrounding brain tissue were calculated in the quantitative susceptibility mapping images. Susceptibility differences at 5, 10, 15, and 20 minutes after acetazolamide administration relative to baseline were calculated in 97 cerebral hemispheres with major cerebral arterial steno-occlusive disease. CBV and the cerebral metabolic rate of oxygen were also calculated using 15O-gas PET in the resting state. RESULTS Dynamic changes of susceptibility after acetazolamide administration were classified into 3 patterns: abnormally increasing 5 or 10 minutes after acetazolamide administration; abnormally decreasing within 20 minutes after acetazolamide administration; and remaining unchanged after acetazolamide administration. CBV was significantly greater in the first pattern than in the latter 2. The cerebral metabolic rate of oxygen differed significantly in descending order from the first to middle to last pattern. CONCLUSIONS Dynamic changes of susceptibility after acetazolamide administration on 7T MR quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in major cerebral arterial steno-occlusive disease.
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Affiliation(s)
- K Fujimoto
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - I Uwano
- Division of Ultrahigh Field MRI, Institute for Biomedical Sciences (I.U., M.S.)
| | - M Sasaki
- Division of Ultrahigh Field MRI, Institute for Biomedical Sciences (I.U., M.S.)
| | - S Oshida
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - S Tsutsui
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - W Yanagihara
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - S Fujiwara
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - M Kobayashi
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - Y Kubo
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - K Yoshida
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.)
| | - K Terasaki
- Cyclotron Research Center (K.T.), Iwate Medical University School of Medicine, Morioka, Japan
| | - K Ogasawara
- From the Department of Neurosurgery (K.F., S.O., S.T., W.Y., S.F., M.K., Y.K., K.Y., K.O.),
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12
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Dehkharghani S, Qiu D. MR Thermometry in Cerebrovascular Disease: Physiologic Basis, Hemodynamic Dependence, and a New Frontier in Stroke Imaging. AJNR Am J Neuroradiol 2020; 41:555-565. [PMID: 32139425 DOI: 10.3174/ajnr.a6455] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/02/2020] [Indexed: 01/20/2023]
Abstract
The remarkable temperature sensitivity of the brain is widely recognized and has been studied for its role in the potentiation of ischemic and other neurologic injuries. Pyrexia frequently complicates large-vessel acute ischemic stroke and develops commonly in critically ill neurologic patients; the profound sensitivity of the brain even to minor intraischemic temperature changes, together with the discovery of brain-to-systemic as well as intracerebral temperature gradients, has thus compelled the exploration of cerebral thermoregulation and uncovered its immutable dependence on cerebral blood flow. A lack of pragmatic and noninvasive tools for spatially and temporally resolved brain thermometry has historically restricted empiric study of cerebral temperature homeostasis; however, MR thermometry (MRT) leveraging temperature-sensitive nuclear magnetic resonance phenomena is well-suited to bridging this long-standing gap. This review aims to introduce the reader to the following: 1) fundamental aspects of cerebral thermoregulation, 2) the physical basis of noninvasive MRT, and 3) the physiologic interdependence of cerebral temperature, perfusion, metabolism, and viability.
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Affiliation(s)
- S Dehkharghani
- From the Department of Radiology (S.D.), New York University Langone Health, New York, New York
| | - D Qiu
- Department of Radiology (D.Q.), Emory University Hospital, Atlanta, Georgia
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Leatherday C, Dehkharghani S, Nahab F, Allen JW, Wu J, Hu R, Qiu D. Cerebral MR oximetry during acetazolamide augmentation: Beyond cerebrovascular reactivity in hemodynamic failure. J Magn Reson Imaging 2018; 50:175-182. [PMID: 30390367 DOI: 10.1002/jmri.26546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/02/2018] [Accepted: 10/02/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Oxygen extraction fraction (OEF) elevation predicts increased ischemic stroke incidence among patients with carotid steno-occlusive disease, and can be estimated from quantitative susceptibility mapping (QSM) MRI. PURPOSE To explore QSM oximetry during acetazolamide (ACZ) challenge, hypothesizing that detectable OEF alterations will reflect hemodynamic compromise in unilateral cerebrovascular disease (CVD) patients. STUDY TYPE Retrospective. SUBJECTS Fourteen unilateral CVD patients, and 24 healthy controls (HC). FIELD STRENGTH/SEQUENCE Multiecho gradient echo (GRE) and T1 -weighted images at 3T. ASSESSMENT We constructed QSM images and R2* maps from multiecho GRE images. QSM-OEF maps were generated from the susceptibility difference between venous blood and background brain tissue. Intrasubject diseased/contralateral hemisphere OEF ratios in the middle cerebral artery (MCA) territories were calculated. Intravascular susceptibility in the straight sinus (SS) and MCA was also measured. STATISTICAL TESTS The result significance was determined using t-tests and Pearson's correlation. RESULTS Mean and standard deviation for the patient diseased/contralateral OEF ratios were 1.15 ± 0.14 at baseline and 1.23 ± 0.17 post-ACZ. Disease group R2* ratios were 0.95 ± 0.05 at baseline and 1.03 ± 0.08 post-ACZ. Left/right OEF and R2* ratios for the HC group were 0.98 ± 0.06 and 0.99 ± 0.038, respectively. Susceptibility (ppb) in the SS and MCA in patients was 162.63 ± 35.4 and -22.33 ± 13.70, respectively, at baseline, 124.56 ± 37.43 and -19.27 ± 23.14 post-ACZ. The HC group SS and MCA susceptibility was 146.10 ± 24.79 and -19.59 ± 12.37, respectively. Patient group OEF ratios were greater than 1.0 before and after ACZ challenge (P < 0.01 and < 0.001, respectively, one-sample t-test), and were greater than HC ratios (P < 0.001 unpaired t-test). OEF and R2* ratios increased from baseline to post-ACZ (P = 0.024, 0.004, respectively, paired t-test). Detectable blood oxygenation change was confirmed by finding SS susceptibility decreased from baseline to post-ACZ (P < 0.001, paired t-test), while MCA susceptibility did not change significantly (P = 0.67, paired t-test). DATA CONCLUSION These results suggest QSM is sensitive to dynamic OEF modulation during hemodynamic augmentation. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:175-182.
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Affiliation(s)
| | | | - Fadi Nahab
- Neurology, Emory University, Atlanta, Georgia, USA
| | - Jason W Allen
- Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA.,Neurology, Emory University, Atlanta, Georgia, USA
| | - Junjie Wu
- Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Ranliang Hu
- Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Deqiang Qiu
- Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
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14
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Xu B, Li C, Guo Y, Xu K, Yang Y, Yu J. Current understanding of chronic total occlusion of the internal carotid artery. Biomed Rep 2017; 8:117-125. [PMID: 29435269 PMCID: PMC5776422 DOI: 10.3892/br.2017.1033] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/12/2017] [Indexed: 01/08/2023] Open
Abstract
At present, there is limited understanding of chronic total occlusion (CTO) of the internal carotid artery (ICA). Therefore, the present report collected related cases from PubMed and reviewed the literature. Cerebral vessels may form collateral circulation immediately or gradually following CTO of the ICA. The natural history of CTO of the ICA includes a variety of outcomes, all of which are biased toward a non-benign progressive process and are characterized by insufficient cerebral perfusion, embolus detachment and cognitive dysfunction. The majority of cases of CTO of the ICA require treatment. In early studies, the results of external-ICA bypass were unsatisfactory, while recanalization is now considered the only viable option. The current treatment indications mainly depend on the degree of injury to the cerebrovascular reserve and the extent to which the oxygen extraction fraction is increased. The length, height and duration of ICA occlusion are also relevant, though more frequently, the condition depends on multiple factors. Endovascular interventional recanalization, carotid endarterectomy (CEA) and hybrid surgery may be conducted in a select group of patients. As novel materials are developed, the success rate of simple recanalization may gradually increase; however, hybrid surgery may be more representative of the current trend, as advanced CEA can remove carotid atherosclerosis plaques, thus reducing the technological demands of the subsequent interventional recanalization. There are many complications that may result from recanalization following CTO of the ICA, including hyperperfusion and technical errors; therefore, the operation must be conducted carefully. If the recanalization is successful, it typically results in a stable improvement of patient condition in the long term. However, despite these conclusions, more studies are required in the future to further improve current understanding of CTO of the ICA.
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Affiliation(s)
- Baofeng Xu
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Chao Li
- Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yunbao Guo
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Kan Xu
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yi Yang
- Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jinlu Yu
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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Fleischer CC, Wu J, Qiu D, Park SE, Nahab F, Dehkharghani S. The Brain Thermal Response as a Potential Neuroimaging Biomarker of Cerebrovascular Impairment. AJNR Am J Neuroradiol 2017; 38:2044-2051. [PMID: 28935624 DOI: 10.3174/ajnr.a5380] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 07/09/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Brain temperature is critical for homeostasis, relating intimately to cerebral perfusion and metabolism. Cerebral thermometry is historically challenged by the cost and invasiveness of clinical and laboratory methodologies. We propose the use of noninvasive MR thermometry in patients with cerebrovascular disease, hypothesizing the presence of a measurable brain thermal response reflecting the tissue hemodynamic state. MATERIALS AND METHODS Contemporaneous imaging and MR thermometry were performed in 10 patients (32-68 years of age) undergoing acetazolamide challenge for chronic, anterior circulation steno-occlusive disease. Cerebrovascular reactivity was calculated with blood oxygen level-dependent imaging and arterial spin-labeling methods. Brain temperature was calculated pre- and post-acetazolamide using previously established chemical shift thermometry. Mixed-effects models of the voxelwise relationships between the brain thermal response and cerebrovascular reactivity were computed, and the significance of model coefficients was determined with an F test (P < .05). RESULTS We observed significant, voxelwise quadratic relationships between cerebrovascular reactivity from blood oxygen level-dependent imaging and the brain thermal response (x coefficient = 0.052, P < .001; x2coefficient = 0.0068, P < .001) and baseline brain temperatures (x coefficient = 0.59, P = .008; x2 coefficient = -0.13, P < .001). A significant linear relationship was observed for the brain thermal response with cerebrovascular reactivity from arterial spin-labeling (P = .001). CONCLUSIONS The findings support the presence of a brain thermal response exhibiting complex but significant interactions with tissue hemodynamics, which we posit to reflect a relative balance of heat-producing versus heat-dissipating tissue states. The brain thermal response is a potential noninvasive biomarker for cerebrovascular impairment.
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Affiliation(s)
- C C Fleischer
- From the Department of Biomedical Engineering (C.C.F., S.-E.P.), Emory University and Georgia Institute of Technology, Atlanta, Georgia
- the Departments of Radiology and Imaging Sciences (C.C.F., J.W., D.Q., S.D.)
| | - J Wu
- the Departments of Radiology and Imaging Sciences (C.C.F., J.W., D.Q., S.D.)
| | - D Qiu
- the Departments of Radiology and Imaging Sciences (C.C.F., J.W., D.Q., S.D.)
| | - S-E Park
- From the Department of Biomedical Engineering (C.C.F., S.-E.P.), Emory University and Georgia Institute of Technology, Atlanta, Georgia
| | - F Nahab
- Neurology (F.N., S.D.)
- Pediatrics (F.N.), Emory University School of Medicine, Atlanta, Georgia
| | - S Dehkharghani
- the Departments of Radiology and Imaging Sciences (C.C.F., J.W., D.Q., S.D.)
- Neurology (F.N., S.D.)
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