scholarly journals Clinical and Radiological Correlates of Reduced CBF Measured Using MRI

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 317-318
Author(s):  
Vincent N Thijs ◽  
Tobias Neumann-Haefelin ◽  
Michael E Moseley ◽  
Michael P Marks ◽  
Gregory W Albers
Keyword(s):  
Symptom Onset ◽  
Cerebral Blood Volume ◽  
Arterial Input Function ◽  
Mean Transit Time ◽  
Input Function ◽  
Lesion Volume ◽  
Time Curve ◽  
Measured Concentration ◽  
Ischemic Lesion ◽  
Adc Values

11 Background and purpose Methods for determining CBF using IV bolus tracking MRI have recently become available. Reduced apparent diffusion coefficient (ADC) values of brain tissue are associated with reductions in regional cerebral blood flow (rCBF). We studied the clinical and radiological features of patients with severe reductions of rCBF on MRI and analysed the relationship between reduced rCBF and ADC. Methods We studied patients with non-lacunar acute ischemic stroke in whom PWI and DWI MRI were performed within 7 hours after symptom onset. A PWI>DWI mismatch of >20% was required. Maps of rCBF, cerebral blood volume (rCBV) and mean transit time (rMTT) were generated after deconvoluting the measured concentration-time curve with the arterial input function using singular value decomposition. The ischemic lesion was outlined on the MTT map and the region of interest (ROI) transferred to the rCBF and rCBV map. ADC-maps were calculated. ADC lesions were defined as regions with ADC values ≤ 550 μm m2/sec. We compared the characteristics of patients with ischemic lesions that had a relative CBF of <50% to the contralateral hemisphere to patients with lesions that had relative CBF of >50%. Characteristics analysed included age, time to MRI, baseline NIHSS, mean ADC, DWI lesion volume, PWI lesion volume and absolute mismatch volume. Results Fifteen patients with an initial PWI>DWI mismatch of >20% were included. Ten had lesions with rCBF of >50% (median 60%) and five patients had rCBF of <50% (median 27.7%). Patients with rCBF <50% had lower ADC values (median 431 μmm2/sec versus 506 μ mm2/sec, p=0.028), larger DWI volumes (median 75.6 cm 3 versus 8.6 cm 3 , p=0.001) and larger PWI lesions as defined by the MTT volume (median 193 cm 3 versus 69 cm 3 , p=0.028) and more severe baseline NIHSS scores (median 18 versus 9, p=0.019). The rMTT and rCBV of the lesions were similar in both groups, as were the age, the absolute mismatch volume and the time from symptom onset to MRI. Conclusion These data indicate that ischemic lesions with severe CBF reductions, measured with new MRI techniques, are associated with a lower mean ADC, larger DWI and PWI lesion volumes and a higher NIHSS score.

scholarly journals Arterial input function and gray matter cerebral blood volume measurements in children

2015 ◽  
Vol 43 (4) ◽  
pp. 981-989 ◽  
Author(s):  
Stephanie B. Withey ◽  
Jan Novak ◽  
Lesley MacPherson ◽  
Andrew C. Peet
Keyword(s):  
Blood Volume ◽  
Gray Matter ◽  
Cerebral Blood Volume ◽  
Arterial Input Function ◽  
Input Function ◽  
Volume Measurements

scholarly journals Perfusion reduction in the absence of structural differences in cognitively impaired versus unimpaired RRMS patients

2016 ◽  
Vol 22 (13) ◽  
pp. 1685-1694 ◽  
Author(s):  
Seyed-Parsa Hojjat ◽  
Charles Grady Cantrell ◽  
Timothy J Carroll ◽  
Rita Vitorino ◽  
Anthony Feinstein ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Depression Scale ◽  
Cognitive Testing ◽  
Cognitively Impaired ◽  
Lesion Volume ◽  
Structural Differences ◽  
Magnetic Resonance Imaging Mri ◽  
Relapsing Remitting Multiple Sclerosis

Background: Cognitive impairment affects 40%–68% of relapsing-remitting multiple sclerosis (RRMS) patients. Gray matter (GM) demyelination is complicit in cognitive impairment, yet cortical lesions are challenging to image clinically. We wanted to determine whether cortical cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) differences exist between cognitively impaired (CI) and unimpaired (NI) RRMS. Methods: Prospective study of healthy controls ( n = 19), CI ( n = 20), and NI ( n = 19) undergoing magnetic resonance imaging (MRI) and cognitive testing <1 week apart. White matter (WM) T2 hyperintense lesions and T1 black holes were traced. General linear regression assessed the relationship between lobar WM volume and cortical and WM CBF, CBV, and MTT. Relationship between global and lobar cortical CBF, CBV, and MTT and cognitive impairment was tested using a generalized linear model. Adjusted Bonferroni p < 0.005 was considered significant. Results: No significant differences for age, gender, disease duration, and any fractional brain or lesion volume were demonstrated for RRMS subgroups. Expanded Disability Status Scale (EDSS) and Hospital Anxiety and Depression Scale–Depression (HADS-D) were higher in CI. Lobar cortical CBF and CBV were associated with cognitive impairment ( p < 0.0001) after controlling for confounders. Cortical CBV accounted for 7.2% of cognitive impairment increasing to 8.7% with cortical CBF ( p = 0.06), while WM and cortical CBF accounted for 8.2% of variance ( p = 0.04). Conclusion: Significant cortical CBF and CBV reduction was present in CI compared to NI in the absence of structural differences.

ANTONIA Perfusion and Stroke

2014 ◽  
Vol 53 (06) ◽  
pp. 469-481 ◽  
Author(s):  
B. Cheng ◽  
A. Kemmling ◽  
G. Thomalla ◽  
J. Fiehler ◽  
N. D. Forkert
Keyword(s):  
Ischemic Stroke ◽  
Quantitative Analysis ◽  
Acute Ischemic Stroke ◽  
Arterial Input Function ◽  
Software Tool ◽  
Input Function ◽  
Lesion Volume ◽  
Acute Ischemic Stroke Patient ◽  
Stroke Research ◽  
Selection Of

SummaryObjectives: The objective of this work is to present the software tool ANTONIA, which has been developed to facilitate a quantitative analysis of perfusion-weighted MRI (PWI) datasets in general as well as the subsequent multi-parametric analysis of additional datasets for the specific purpose of acute ischemic stroke patient dataset evaluation.Methods: Three different methods for the analysis of DSC or DCE PWI datasets are currently implemented in ANTONIA, which can be case-specifically selected based on the study protocol. These methods comprise a curve fitting method as well as a deconvolution-based and deconvolution-free method integrating a previously defined arterial input function. The perfusion analysis is extended for the purpose of acute ischemic stroke analysis by additional methods that enable an automatic atlas-based selection of the arterial input function, an analysis of the perfusion-diffusion and DWI-FLAIR mismatch as well as segmentation-based volumetric analyses.Results: For reliability evaluation, the de-scribed software tool was used by two ob-servers for quantitative analysis of 15 data-sets from acute ischemic stroke patients to extract the acute lesion core volume, FLAIR ratio, perfusion-diffusion mismatch volume with manually as well as automatically selected arterial input functions, and follow-up lesion volume. The results of this evaluation revealed that the described software tool leads to highly reproducible results for all parameters if the automatic arterial input function selection method is used.Conclusion: Due to the broad selection of processing methods that are available in the software tool, ANTONIA is especially helpful to support image-based perfusion and acute ischemic stroke research projects.

Abstract T P37: Cerebral Blood Volume Does Not Differentiate Regions With Persistent Cerebral Hypoperfusion That Infarct From Those That Survive: A DEFUSE 2 Substudy

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Sharan K Mann ◽  
Soren Christensen ◽  
Michael Mlynash ◽  
Stephanie Kemp ◽  
Maarten G Lansberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
T Test ◽  
Cerebral Hypoperfusion ◽  
Lesion Volume ◽  
Mri Scan ◽  
Paired T Test

Background: The optimal Tmax threshold for predicting critically hypoperfused tissue is a delay of >6 seconds. However, persistent Tmax >6s lesions do not invariably progress to infarction. Differences in cerebral blood volume (CBV) may explain why some regions of persistent cerebral hypoperfusion (PCHP) infarct whereas others survive. We hypothesized that CBV is higher in areas of PCHP that survive versus those that infarct. Methods: We included patients that had: 1) a Tmax >6s lesion on baseline and early follow-up MRI perfusion scans, and 2) a FLAIR lesion on the day 5 MRI scan. Regions of PCHP had to meet two criteria: 1) Tmax >6s positive on both baseline and co-registered early follow-up MRI perfusion scans, and 2) DWI negative on the baseline MRI scan. PCHP regions were classified as PCHP-infarct if there was a corresponding lesion on the co-registered 5 day FLAIR and as PCHP-survival if there was no corresponding lesion. Patients with no region of either PCHP-infarct or PCHP-survival were excluded. The study had two parts. In part 1, the paired t-test was used to compare lesion volume, CBV, cerebral blood flow (CBF), mean transit time (MTT), and Tmax between PCHP-infarct and PCHP-survival regions within each patient. In part 2, the 2-sample t-test was used to compare mean volume, CBV, CBF, MTT, and Tmax in PCHP-infarct and PCHP-survival regions for all patients together as a group. Results: 61 patients were included in the analysis. Mean total PCHP volume was 26cc (16cc infarct, 10cc survival) and median total PCHP volume was 15cc (9cc infarct, 6cc survival). For part 1, CBV was not different in PCHP-infarct versus PCHP-survival (P=0.16). CBF was higher (P=0.05) in regions of PCHP-survival, and MTT and Tmax were less prolonged (P=0.03 and P < 0.01). For part 2, mean CBV and MTT did not differ between PCHP-infarct and PCHP-survival (P=0.23 and P=0.40). Mean CBF trended higher (P=0.07) and mean Tmax delays were milder (P= 0.04) in PCHP-survival. Conclusion: CBV does not differ between regions of PCHP-infarct versus PCHP-survival and does not explain why some areas of persistent, severe hypoperfusion survive. Tmax was less severely delayed and CBF values were higher in regions of PCHP-survival, which warrant further study.

Abstract TP49: Irreversible Ischemic Lesion Characterization: Does CBV_ASPECTS Add to CT_ASPECTS?

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Marina Padroni ◽  
Pilar Coscojuela ◽  
Sandra Boned ◽  
Marc Ribó ◽  
Jordi Cabero ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Symptom Onset ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Relevant Information ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Anterior Circulation ◽  
Ischemic Lesion

Introduction: The best technique for selecting acute stroke patients for reperfusion therapies is not defined yet. ASPECTS is a useful score for assessing the extent of early ischemic signs in the anterior circulation on non-contrast CT (CT). Cerebral blood volume (CBV) on CT perfusion (CTP) defines the core lesion assumed to be irreversibly damaged. Whether CBV provides additional information over CT in the initial ASPECTS assessment is unknown. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume. Methods: Consecutive patients with middle cerebral or internal carotid artery occlusion who underwent endovascular reperfusion treatment according to initial CT_ASPECTS≥7 were studied. CBV_ASPECTS was assessed blindly later-on. Recanalization was defined as TICI2b3. Final infarct volumes were measured on follow-up imaging. We defined an irrelevant ASPECTS difference (IAD) as: CT_ASPECTS - CBV_ASPECTS≤1. Results: Sixty-five patients, mean age 67±14, median NIHSS:16(10-20) were studied. Recanalization rate was: 78.5%. Median CT_ASPECTS was 9(8-10), and CBV_ASPECTS 8(8-10). Mean time from symptom onset to CT was 219±143 min. 50 patients (76.9%) showed an IAD. The ASPECTS difference was inversely correlated to the time from symptom onset to CT (r:-0.36, p<0.01). A ROC curve defined 120 minutes as the best cut-off time point after which the ASPECTS difference becomes irrelevant. The rate of IAD was significantly higher after 120 minutes (89.5% Vs 37.5; p<0.01). CBV_ASPECTS but not CT_ASPECTS correlated to the final infarct (r:-0.33, p<0.01). However, if CT was done >2 hours after symptom onset, then CT_ASPECTS was correlated to final infarct (r:-0.39, p=0.01). No other variables were associated with CT-CBV_ASPECTS difference. Conclusions: In acute stroke patient CBV_ASPECTS correlates with final infarct volume. However, when CT is performed after 120 minutes from symptoms onset CBV_ASPECTS does not add relevant information to CT_ASPECTS.

scholarly journals The Efficacy of Calculation of Mean Transit Time without Using Arterial Input Function : A Trial of Classification of Perfusion Reserve Capacity using Perfusion MRI

2003 ◽  
Vol 12 (10) ◽  
pp. 676-684
Author(s):  
Masahiro Furuichi ◽  
Yuzo Araki ◽  
Hiroaki Nokura ◽  
Ayumi Okumura ◽  
Shinichi Yoshimura ◽  
...  
Keyword(s):  
Transit Time ◽  
Arterial Input Function ◽  
Mean Transit Time ◽  
Input Function ◽  
Perfusion Mri ◽  
Reserve Capacity ◽  
Perfusion Reserve

scholarly journals Magnetic resonance imaging-based changes in vascular morphology and cerebral perfusion in subacute ischemic stroke

2021 ◽  
pp. 0271678X2110100
Author(s):  
Anna Kufner ◽  
Ahmed A Khalil ◽  
Ivana Galinovic ◽  
Elias Kellner ◽  
Ralf Mekle ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Mixed Models ◽  
Cerebral Blood Volume ◽  
Controlled Trial ◽  
Stroke Severity ◽  
Lesion Volume ◽  
Ischemic Lesion ◽  
Vessel Size ◽  
Cerebral Microvasculature

MRI-based vessel size imaging (VSI) allows for in-vivo assessment of cerebral microvasculature and perfusion. This exploratory analysis of vessel size (VS) and density (Q; both assessed via VSI) in the subacute phase of ischemic stroke involved sixty-two patients from the BAPTISe cohort (‘Biomarkers And Perfusion--Training-Induced changes after Stroke’) nested within a randomized controlled trial (intervention: 4-week training vs. relaxation). Relative VS, Q, cerebral blood volume (rCBV) and –flow (rCBF) were calculated for: ischemic lesion, perilesional tissue, and region corresponding to ischemic lesion on the contralateral side (mirrored lesion). Linear mixed-models detected significantly increased rVS and decreased rQ within the ischemic lesion compared to the mirrored lesion (coefficient[standard error]: 0.2[0.08] p = 0.03 and −1.0[0.3] p = 0.02, respectively); lesion rCBF and rCBV were also significantly reduced. Mixed-models did not identify time-to-MRI, nor training as modifying factors in terms of rVS or rQ up to two months post-stroke. Larger lesion VS was associated with larger lesion volumes (β 34, 95%CI 6.2–62; p = 0.02) and higher baseline NIHSS (β 3.0, 95%CI 0.49–5.3;p = 0.02), but was not predictive of six-month outcome. In summary, VSI can assess the cerebral microvasculature and tissue perfusion in the subacute phases of ischemic stroke, and may carry relevant prognostic value in terms of lesion volume and stroke severity.

scholarly journals Clinically Meaningful MRI Perfusion Abnormalities in Acute Stroke: Comparison of Analytic Techniques

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 339-339
Author(s):  
Chen-Sen Wu ◽  
Lawrence L Latour ◽  
Steven Warach
Keyword(s):  
At Risk ◽  
Acute Stroke ◽  
Moment Method ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Clinical Severity ◽  
Perfusion Parameter ◽  
Time Curve ◽  
Time To Peak ◽  
First Moment

P2 Background: MRI perfusion imaging (PWI) can demonstrate hemodynamic abnormalities in acute stroke. The volume of hypoperfusion derived from calculated perfusion parameter maps has been used to predict tissue at risk for infarction and to identify presumptive ischemic penumbra. It is unclear how best to distinguish true tissue at risk from benign hypoperfusion. A first step toward this goal is identifying clinically significant PWI abnormalities in stroke patients. Our purpose was to evaluate four different perfusion parameter maps to determine which algorithm best correlates with clinical severity. Methods: Twenty patients were retrospectively selected from our database. Selection criteria included 1) acute hemispheric lesion, 2) MRI within 24 hours of symptom onset, and 3) no history of prior stroke. Perfusion maps were derived using four different algorithms to estimate relative mean transit time (rMTT): 1) cerebral blood volume (CBV) / cerebral blood flow (CBF), 2) CBV / peak of the concentration-time curve, 3) time to peak (TTP), and 4) ratio of the 1 st / 0 th moment of the transfer function (first moment method). Abnormal perfusion volumes were derived from ever-increasing thresholds of rMTT delay relative to normal contralateral tissue. The volumes at each delay threshold were correlated with National Institutes of Health Stroke Scale (NIHSS) for each algorithm. Results: Significant correlations between hypoperfusion volumes and NIHSS were found for all algorithms. The first moment method had the highest correlation (r = 0.76) and the correlations for this method were independent of the delay threshold used to derive the volumes. For the other algorithms, the best correlations were observed for volumes including only voxels with delays of 4 seconds or greater. Conclusions: This analysis suggests that the first moment method may have advantages over the others in determining the correlation of hypoperfusion volume to NIHSS. Further analyses correlating acute hypoperfusion volumes to final infarct volumes may help refine the choice of best analytic method for determining clinically relevant PWI abnormalities.

scholarly journals CBV_ASPECTS Improvement over CT_ASPECTS on Determining Irreversible Ischemic Lesion Decreases over Time

2016 ◽  
Vol 5 (3-4) ◽  
pp. 140-147 ◽  
Author(s):  
Marina Padroni ◽  
Sandra Boned ◽  
Marc Ribó ◽  
Marian Muchada ◽  
David Rodriguez-Luna ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Relevant Information ◽  
Anterior Circulation ◽  
Ischemic Lesion ◽  
Noncontrast Computed Tomography ◽  
Mean Time

The Alberta Stroke Program Early CT Score (ASPECTS) is a useful scoring system for assessing early ischemic signs on noncontrast computed tomography (CT). Cerebral blood volume (CBV) on CT perfusion defines the core lesion assumed to be irreversibly damaged. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume according to time. Methods: Consecutive patients with anterior circulation stroke who underwent endovascular reperfusion according to initial CT_ASPECTS ≥7 were studied. CBV_ASPECTS was assessed blindly later on. Recanalization was defined as thrombolysis in cerebral ischemia score 2b-3. Final infarct volumes were measured on follow-up imaging. We compared ASPECTS on CBV and CT images, and defined ASPECTS agreement as: CT_ASPECTS - CBV_ASPECTS ≤1. Results: Sixty-five patients, with a mean age of 67 ± 14 years and a median National Institutes of Health Stroke Scale score of 16 (range 10-20), were studied. The recanalization rate was 78.5%. The median CT_ASPECTS was 9 (range 8-10), and the CBV_ASPECTS was 8 (range 8-10). The mean time from symptoms to CT was 219 ± 143 min. Fifty patients (76.9%) showed ASPECTS agreement. The ASPECTS difference was inversely correlated to the time from symptoms to CT (r = -0.36, p < 0.01). A ROC curve defined 120 min as the best cutoff point after which the ASPECTS difference becomes more frequently ≤1. After 120 min, 89.5% of the patients showed ASPECTS agreement (as compared with 37.5% for <120 min, p < 0.01). CBV_ASPECTS but not CT_ASPECTS correlated with final infarct (r = -0.33, p < 0.01). However, if CT was done >2 h after symptom onset, CT_ASPECTS also correlated to final infarct (r = -0.39, p = 0.01). Conclusions: In acute stroke, CBV_ASPECTS correlates with the final infarct volume. However, when CT is performed after 120 min from symptom onset, CBV_ASPECTS does not add relevant information to CT_ASPECTS.

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