MRI investigation of vascular remodeling for heterogeneous edema lesions in subacute ischemic stroke rat models: Correspondence between cerebral vessel structure and function

2021 ◽  
pp. 0271678X2110291
Author(s):  
MungSoo Kang ◽  
Seokha Jin ◽  
HyungJoon Cho
Keyword(s):  
Vascular Remodeling ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Light Sheet ◽  
Artery Occlusion ◽  
Strong Positive Correlation ◽  
Cerebral Vessel ◽  
Rat Models ◽  
Apparent Diffusion Coefficient Values ◽  
Vessel Structure

The spatial heterogeneity in the temporal occurrence of pseudo-normalization of MR apparent diffusion coefficient values for ischemic lesions may be related to morphological and functional vascular remodeling. As the area of accelerated pseudo-normalization tends to expand faster and more extensively into the chronic stage, detailed vascular characterization of such areas is necessary. During the subacute stage of transient middle cerebral artery occlusion rat models, the morphological size of the macrovasculature, microvascular vessel size index (VSI), and microvessel density (MVD) were quantified along with functional perfusion measurements of the relative cerebral blood flow (rCBF) and mean transit time (rMTT) of the corresponding areas (33 cases for each parameter). When compared with typical pseudo-normalization lesions, early pseudo-normalization lesions exhibited larger VSI and rCBF (p < 0.001) at reperfusion days 4 and 7, along with reduced MVD and elongated rMTT (p < 0.001) at reperfusion days 1, 4, and 7. The group median VSI and rCBF exhibited a strong positive correlation (r = 0.92), and the corresponding MVD and rMTT showed a negative correlation (r = −0.48). Light sheet fluorescence microscopy images were used to quantitatively validate the corresponding MRI-derived microvascular size, density, and cerebral blood volume.

Cerebral blood volume lesion extent predicts functional outcome in patients with vertebral and basilar artery occlusion

2017 ◽  
Vol 14 (5) ◽  
pp. 540-547 ◽  
Author(s):  
Fana Alemseged ◽  
Darshan G Shah ◽  
Andrew Bivard ◽  
Timothy J Kleinig ◽  
Nawaf Yassi ◽  
...  
Keyword(s):  
Blood Volume ◽  
Basilar Artery ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Intraclass Correlation ◽  
Artery Occlusion ◽  
Posterior Circulation ◽  
Basilar Artery Occlusion ◽  
Area Under Roc Curve

Background CT perfusion may improve diagnostic accuracy in posterior circulation stroke. The posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) on Computed Tomography Angiography source images (CTA-SI) predicts functional outcome in patients with basilar artery occlusion. Aims We assessed the prognostic value of pc-ASPECTS on CT perfusion in patients with vertebral and basilar artery occlusion (VBAO) in comparison with CTA-SI. Methods Whole-brain CT perfusion from consecutive stroke patients with VBAO at four stroke centers was retrospectively analyzed. pc-ASPECTS – a 10-point score assessing hypoattenuation on CTA-SI – was calculated from CT perfusion parameters as focally reduced cerebral blood flow or cerebral blood volume, focally increased time to peak of the deconvolved tissue residue function (Tmax) or mean transit time. Two investigators independently reviewed the images. Reliability was assessed with intraclass correlation coefficient. Good outcome was defined as modified Rankin scale ≤3 at three months. Results We included 60 patients with VBAO. After assessment of four CT perfusion maps simultaneously, area-under-ROC curve (AROC) was 0.83 (95%CI 0.72–0.93) for cerebral blood volume, 0.76 (95%CI 0.64–0.89) for cerebral blood flow, 0.77 (95%CI 0.64–0.89) for Tmax, 0.70 (95%CI 0.56–0.84) for mean transit time versus area-under-ROC curve 0.64 (95%CI 0.50–0.79) for CTA-SI. Cerebral blood volume had greater accuracy compared with CTA-SI for poor outcome (p = 0.04). In logistic regression analysis, cerebral blood volume pc-ASPECTS≤8 was independently associated with poor outcome (OR 9.3 95%CI 2.2–41; p = 0.003, adjusted for age and clinical severity). Inter-rater agreement was substantial for cerebral blood volume pc-ASPECTS (intraclass correlation coefficient 0.82 95%CI 0.71–0.90 versus 0.67 for CTA-SI 95%CI 0.43–0.81). Conclusions Cerebral blood volume pc-ASPECTS may identify VBAO patients at higher risk of disability.

Abstract 3303: Detection of cerebral vasospasm using Dynamic CT: Analysis of Volume Perfusion CT Maps and 4D-CT Angiography

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Peter Schramm ◽  
Karoline Dolatowski ◽  
Ramona Schramm ◽  
Andreas Froelich ◽  
Ernst Klotz ◽  
...  
Keyword(s):  
Cerebral Vasospasm ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Relevant Information ◽  
Vessel Diameter ◽  
Perfusion Ct ◽  
Cerebral Hypoperfusion ◽  
Arterial Phase ◽  
Arterial Vasospasm ◽  
Stenotic Lesions

Introduction: Cerebral vasospasm with a raised risk for secondary ischemia is a frequent complication after subarachnoid hemorrhage (SAH). The early diagnosis of focal or global cerebral hypoperfusion is important in order to allow treatment before irreversible ischemic damage occurs (intensive care and/or neurointervention). We tested, whether the implementation of “whole brain” volume Perfusion CT (VPCT) for the examination of patients with suspected cerebral vasospasm delivers relevant information about the localization and characteristics of arterial vasospasm and the volume at risk of secondary infarction. Patients and Methods: Patients were eligible for this study, if they had been admitted to our department with suspicion of cerebral vasospasm due to SAH. Patients first received a non-contrast CT of the brain to exclude acute hydrocephalus. After that, VPCT was performed. CT angiographic axial and coronal maximum-intensity projections (MIP) were generated from thin slice recons of the VPCT dataset at peak arterial time. Images were assessed for presence of arterial vasospasm or occlusion and compared with conventional CTA or DSA. The distribution of ischemic lesions was analyzed on 3D perfusion parameter maps of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to drain (TTD). Results: 11 patients with SAH were examined with VPCT. In all patients, focal areas of cerebral hypoperfusion were detected on the color coded VPCT parameter maps. The highest sensitivity was found for MTT and TTD. Focal reductions of CBV strongly correlated with infarction on follow-up CT. 8 patients (73%) had focal stenotic lesions of intracranial artery segments due to vasospasm visible on the thin MIP reconstructions of the 4D CTA arterial phase. All of these stenotic lesions were also visible on conventional CTA or DSA, resulting in 100% sensitivity of the 4D CTA reconstructions. In 2 patients, balloon angioplasty of the vasospastic segments was performed subsequently; in both patients, VPCT showed normalization of both the perfusion maps and the vessel diameter afterwards. Conclusion: VPCT is a non-invasive method that allows detecting cerebral vasospasm in patients suffering from SAH. It has the potential to demonstrate brain areas with a focal perfusion deficit as well as vasospastic arterial segments. DSA will remain the gold standard for detection of cerebral vasospasm, but VPCT has the potential to improve diagnosis and treatment decisions in patients suffering from vasospasm due to SAH.

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.

Correlation between cognitive impairment and cerebral hemodynamic disturbances on perfusion magnetic resonance imaging in European adults with moyamoya disease

2010 ◽  
Vol 113 (4) ◽  
pp. 753-759 ◽  
Author(s):  
Lionel Calviere ◽  
Isabelle Catalaa ◽  
Fabienne Marlats ◽  
Alain Viguier ◽  
Fabrice Bonneville ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Moyamoya Disease ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Perfusion Magnetic Resonance Imaging ◽  
Cerebrovascular Reserve ◽  
Cerebral Hemodynamic ◽  
Perfusion Mr ◽  
Perfusion Mr Imaging ◽  
Relationship Of

Object Although cognitive impairment has been reported in adults with moyamoya disease (MMD), its relationship with cerebral hemodynamic disturbances has not been investigated. The aims of the present study were to confirm the presence of dysexecutive cognitive syndrome (DCS) in adults with MMD and to explore the relationship of DCS with frontal lobe perfusion as measured by perfusion MR imaging. Methods Cerebral blood volume (CBV) ratio and mean transit time delay were measured in frontal and temporoparietal regions using the cerebellum as a reference region in 10 European adults with MMD. In addition, the authors calculated the cerebrovascular reserve (CVR) using the CBV ratio and the acetazolamide challenge. All patients underwent a standardized neuropsychological assessment test battery. The authors defined DCS as an impairment shown on 3 tests or more of executive function. Results The authors found DCS in 6 patients. The frontal CVR was lower in patients with DCS than in patients without DCS (mean ± SD: −13.5 ± 13.2% and 20.3 ± 21.3%; p = 0.019, Mann-Whitney U-test). Other parameters of frontal perfusion and temporoparietal CVR were not correlated with DCS. Conclusions The authors' findings suggest that DCS is common in European adults with MMD and may be related to frontal perfusion impairment.

scholarly journals The effect of carotid artery stenting on capillary transit time heterogeneity in patients with carotid artery stenosis

2018 ◽  
Vol 3 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Ethem M Arsava ◽  
Mikkel B Hansen ◽  
Berkan Kaplan ◽  
Ahmet Peker ◽  
Rahsan Gocmen ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Transit Time ◽  
Carotid Artery Stenting ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Oxygen Extraction Fraction ◽  
Consecutive Series ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Vascular Events

Introduction Carotid revascularisation improves haemodynamic compromise in cerebral circulation as an additional benefit to the primary goal of reducing future thromboembolic risk. We determined the effect of carotid artery stenting on cerebral perfusion and oxygenation using a perfusion-weighted MRI algorithm that is based on assessment of capillary transit-time heterogeneity together with other perfusion and metabolism-related metrics. Patients and methods A consecutive series of 33 patients were evaluated by dynamic susceptibility contrast perfusion-weighted MRI prior to and within 24 h of the endovascular procedure. The level of relative change induced by stenting, and relationship of these changes with respect to baseline stenosis degree were analysed. Results Stenting led to significant increase in cerebral blood flow ( p < 0.001), and decrease in cerebral blood volume ( p = 0.001) and mean transit time ( p < 0.001); this was accompanied by reduction in oxygen extraction fraction ( p < 0.001) and capillary transit-time heterogeneity ( p < 0.001), but an overall increase in relative capillary transit-time heterogeneity (RTH: CTH divided by MTT; p = 0.008). No significant change was observed with respect to cerebral metabolic rate of oxygen. The median volume of tissue with MTT > 2s decreased from 24 ml to 12 ml ( p = 0.009), with CTH > 2s from 29 ml to 19 ml ( p = 0.041), and with RTH < 0.9 from 61 ml to 39 ml ( p = 0.037) following stenting. These changes were correlated with the baseline degree of stenosis. Discussion: Stenting improved the moderate stage of haemodynamic compromise at baseline in our cohort. The decreased relative transit-time heterogeneity, which increases following stenting, is probably a reflection of decreased functional capillary density secondary to chronic hypoperfusion induced by the proximal stenosis. Conclusion: Carotid artery stenting, is not only important for prophylaxis of future vascular events, but also is critical for restoration of microvascular function in the cerebral tissue.

Abstract 2972: Perfusion CT in Patients with Basilar Artery Occlusion: Diagnostic and Prognostic Value in the Basilar Artery International Cooperation Study

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Lars P Pallesen ◽  
Volker Puetz ◽  
Johannes Gerber ◽  
Imanuel Dzialowski ◽  
Patrik Michel ◽  
...  
Keyword(s):  
International Cooperation ◽  
Basilar Artery ◽  
Mean Transit Time ◽  
Univariate Analysis ◽  
Artery Occlusion ◽  
Perfusion Ct ◽  
Posterior Circulation ◽  
Basilar Artery Occlusion ◽  
Relative Reduction ◽  
Prognostic Impact

Background: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) applied to CT angiography source images (CTA-SI) predicts the functional outcome of patients with basilar artery occlusion (BAO). Compared with CTA-SI, perfusion CT (CTP) may provide added information. We assessed the diagnostic and prognostic impact of CTP compared with CTA-SI among patients in the Basilar Artery International Cooperation Study (BASICS) Methods: BASICS was a prospective observational registry of consecutive patients with acute symptomatic BAO. We applied pc-ASPECTS to CTA-SI and cerebral blood volume (CBV), cerebral blood flow (CBF), time-to-peak (TTP) and mean-transit-time (MTT) parameter maps in a 3-reader-consensus with readers blinded to clinical data. Hypoattenuation on CTA-SI, a relative reduction in CBV or CBF, or relative increase in MTT or TTP was rated as abnormal. Clinical outcome was measured with the modified Rankin Scale (mRS) score at 1 month. Results: Among 592 patients in the BASICS registry, 27 patients (4.6%) had CTP studies performed. Median (interquartile-range) pc-ASPECTS values on TTP/MTT, CTA-SI, CBF and CBV were 6 (5-8), 7 (5-9), 8 (6-9) and 10 (8.75-10), respectively (p<0.001). The proportion of patients with any perfusion abnormalities in the posterior circulation was highest for TTP/MTT (93%; CI 95% 74% to 99%), compared with 78% (CI 95% 57% to 91%) for both CTA-SI and CBF and 46% (CI 95% 27% to 66%) for CBV (p<0.001). At 1 month, 9 patients (33%) had a favourable outcome (mRS scores 0-3), 8 patients (30%) had an unfavourable outcome (mRS scores 4-5) and 10 patients (37%) were deceased. In univariate analysis, pc-ASPECTS scores did not correlate with outcome mRS scores for all imaging modalities (Spearman’s Rho, p>0.1 for all). All three patients (100%) with a CBV pc-ASPECTS <8 compared to 6 of 23 patients (26%) with a CBV pc-ASPECTS >8 died (p=0.03). Conclusion: CTP was performed in a minority of patients in the BASICS registry population. Perfusion disturbances in the posterior circulation were most frequent and most pronounced on TTP and MTT parameter maps. Extensive reduction of CBV, defined as a pc-ASPECTS <8, may indicate patients with a high case fatality.

Abstract 2619: Autoregulation of Cerebral Blood Flow is Preserved in Primary Intracerebral Hemorrhage

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
E B Gould ◽  
Rebecca McCourt ◽  
Sana Vahidy ◽  
Negar Asdaghi ◽  
Michael D Hill ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracerebral Hemorrhage ◽  
Cerebral Autoregulation ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Serial Ct ◽  
Acute Intracerebral Hemorrhage ◽  
Perfusion Maps

Background: Treatment of hypertension during acute intracerebral hemorrhage (ICH) is controversial. There are concerns that in the context of disrupted cerebral autoregulation, blood pressure (BP) reduction may cause decreased cerebral blood flow (CBF), particularly in the perihematoma region. CBF was assessed using serial CT perfusion (CTP) studies. We hypothesized that CBF would remain stable following BP reduction. Methods: Acute primary ICH patients were imaged pre and post BP treatment. Perfusion maps were calculated from CTP source images. Mean CBF was measured in a 1cm perihematoma region, contralateral homologous regions and in both hemispheres. Mean cerebral blood volume (CBV), mean transit time (MTT), and time to drain (TTD) were calculated in the same manner. Relative measures (i.e. rCBF) were calculated as ratios/differences between ipsilateral and contralateral regions. Results: Sixteen patients (median age 75 (54-91)) were imaged with CTP (median time from onset 19.4 (2.0-72.2) h) and re-imaged 2.0 (1.1-3.3) h later. Median NIHSS at baseline was 9 (2-24); this remained stable at the time of the second CTP (10 (2-24), P=0.14). Baseline hematoma volume was 24.8±19.9 ml and there was no change at the time of the second CTP (26.3±22.1 ml, P=0.16). Patients were recruited from an ongoing trial, in which they were randomly treated to a target systolic BP of <150mmHg (n=9) or <180mmHg (n=7). Four patients received no antihypertensives as BP was below target at the time of randomization. Mean systolic BP in treated patients (n=12) decreased significantly between the first (165±23 mmHg) and second (143±18 mmHg, P<0.0001) CTP scans. Mean perihematoma CBF in treated patients was stable with BP reduction (pre=35.1±7.1 vs. post=35.4±6.2 ml/100g/min, P=0.87). Ipsilateral hemispheric CBF was also stable (pre=47.3±7.2 vs. post=46.4±7.1 ml/100g/min, P=0.66). Although perihematoma CBF was lower than in contralateral homologous regions (rCBF=0.72±0.11), BP reduction did not decrease this further (0.74±0.14 post-treatment, P=0.58). Ipsilateral hemispheric rCBF (0.96±0.06) was also unaffected by BP treatment (0.95±0.08, P=0.64). Perihematoma rCBF decreased in 5 treated patients, but never by >12%. Linear regression showed no relationship between changes in systolic BP and perihematoma rCBF (R=-0.002, [-0.005, 0.001], P=0.18). Perihematoma rCBV (pre=0.77±0.11 vs. post=0.79±0.10, P=0.20), rMTT (pre=0.51±0.54s vs. post=0.70±0.65s, P=0.26) and rTTD (pre=0.71±1.01s vs. post=0.89±0.84s, P=0.42) also remained stable following BP treatment. Conclusions: Acute BP reduction does not appear to exacerbate perihematoma oligaemia. Stability of CBF following acute BP treatment suggests preservation of cerebral autoregulation in ICH, within the range of arterial pressures studied. These findings support the safety of early BP treatment in ICH.

scholarly journals Reflex-Mediated Reduction in Human Cerebral Blood Volume

2005 ◽  
Vol 25 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Timothy D Wilson ◽  
J Kevin Shoemaker ◽  
R Kozak ◽  
T-Y Lee ◽  
Adrian W Gelb
Keyword(s):  
Central Venous Pressure ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Lower Body Negative Pressure ◽  
Mean Transit Time ◽  
Venous Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Lower Body ◽  
Central Venous

Adrenergic nerves innervate the human cerebrovasculature, yet the functional role of neurogenic influences on cerebral hemodynamics remains speculative. In the current study, regional cerebrovascular responses to sympathoexcitatory reflexes were evaluated. In eight volunteers, contrast-enhanced computed tomography was performed at baseline, –40 mmHg lower body negative pressure (LBNP), and a cold pressor test (CPT). Cerebral blood volume (CBV), mean transit time (MTT), and cerebral blood flow (CBF) were evaluated in cortical gray matter (GM), white matter (WM), and basal ganglia/thalamus (BGT) regions. Lower body negative pressure resulted in tachycardia and decreased central venous pressure while mean arterial pressure was maintained. Cold pressor test resulted in increased mean arterial pressure concomitant with tachycardia but no change in central venous pressure. Neither reflex altered end-tidal carbon dioxide. Cerebral blood volume was reduced in GM during both LBNP and CPT ( P<0.05) but was unchanged in WM and BGT. Mean transit time was reduced in WM and GM during CPT ( P<0.05). Cerebral blood flow was only modestly affected with either reflex ( P<0.07). The combined reductions in GM CBV (˜ –25%) and MTT, both with and without any change in central venous pressure, with small CBF changes (˜ –11%), suggest that active venoconstriction contributed to the volume changes. These data demonstrate that CBV is reduced during engagement of sympathoexcitatory reflexes and that these cerebrovascular changes are heterogeneously distributed.

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