Diminished Signal Intensities Distal to Intracranial Arterial Stenosis on Time-of-Flight MR Angiography Might Indicate Delayed Cerebral Perfusion

2016 ◽  
Vol 42 (3-4) ◽  
pp. 232-239 ◽  
Author(s):  
Linfang Lan ◽  
Xinyi Leng ◽  
Jill Abrigo ◽  
Hui Fang ◽  
Vincent H.L. Ip ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Perfusion ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Time Of Flight ◽  
Arterial Stenosis ◽  
Intracranial Arterial Stenosis ◽  
Tof Mra ◽  
Signal Intensities

Background: Intracranial arterial stenosis (ICAS) is a predominant cause of ischemic stroke in Asia. Changes in the signal intensities (SIs) across ICAS lesions on time-of-flight magnetic resonance angiography (TOF-MRA) have been indicated to partially reflect the hemodynamic significance of the lesions, which we aimed to verify by correlating it with cerebral perfusion features provided by CT perfusion (CTP) imaging. Methods: Ischemic stroke or transient ischemic attack patients with unilateral symptomatic stenosis (≥50%) of intracranial internal carotid artery or middle cerebral artery (MCA) were included in this study. Change of SIs across an ICAS lesion on TOF-MRA was calculated by the distal and proximal SI ratio (SIR). Cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) within the MCA territory of ipsilateral and contralateral hemispheres were evaluated on the CTP images at the basal ganglia level. Relative CBV, CBF and MTT were defined as ratios of the values obtained from ipsilateral and contralateral hemispheres. The relationships between SIR and CTP parameters were analyzed. Results: Fifty subjects (74% male, mean age 62) were recruited. Overall, the mean SIR was 0.77 ± 0.17. SIR of ICAS was significantly, linearly and negatively correlated with ipsilateral CBV (r = -0.335, p = 0.017), ipsilateral MTT (r = -0.301, p = 0.034), and ipsilateral/contralateral MTT ratio (r = -0.443, p = 0.001). Conclusions: Diminished SIs distal to ICAS on TOF-MRA might be associated with delayed ipsilateral cerebral perfusion. Changes of the SIs across ICAS lesions on TOF-MRA may be a simple marker to reflect cerebral perfusion changes in patients with symptomatic ICAS.

Collateral Circulation Predicts the Size of the Infarct Core and the Proportion of Salvageable Penumbra in Hyperacute Ischemic Stroke Patients Treated with Intravenous Thrombolysis

2015 ◽  
Vol 40 (3-4) ◽  
pp. 182-190 ◽  
Author(s):  
Harri Rusanen ◽  
Jukka T. Saarinen ◽  
Niko Sillanpää
Keyword(s):  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Collateral Circulation ◽  
Cerebral Blood Volume ◽  
Treatment Time ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Intravenous Thrombolysis ◽  
Stroke Patients ◽  
The Impact

Background: We studied the impact of collateral circulation on CT perfusion (CTP) parametric maps and the amount of salvaged brain tissue, the imaging and clinical outcome at 24 h and at 3 months in a retrospective acute (<3 h) stroke cohort (105 patients) with anterior circulation thrombus treated with intravenous thrombolysis. Methods: Baseline clinical and imaging information were collected and groups with different collateral scores (CS) were compared. Binary logistic regression analyses using good CS (CS ≥2) as the dependent variable were calculated. Results: CTP Alberta Stroke Program Early CT Score (ASPECTS) was successfully assessed in 58 cases. Thirty patients displayed good CS. Poor CS were associated with more severe strokes according to National Institutes of Health Stroke Scale (NIHSS) at arrival (15 vs. 7, p = 0.005) and at 24 h (10 vs. 3, p = 0.003) after intravenous thrombolysis. Good CS were associated with a longer mean onset-to-treatment time (141 vs. 121 min, p = 0.009) and time to CTP (102 vs. 87 min, p = 0.047), better cerebral blood volume (CBV) ASPECTS (9 vs. 6, p < 0.001), better mean transit time (MTT) ASPECTS (6 vs. 3, p < 0.001), better noncontrast CT (NCCT) ASPECTS (10 vs. 8, p < 0.001) at arrival and with favorable clinical outcome at 3 months (modified Rankin Scale ≤2, p = 0.002). The fraction of penumbra that was salvageable at arrival and salvaged at 24 h was higher with better CS (p < 0.001 and p = 0.035, respectively). In multivariate analysis, time from the onset of symptoms to imaging (p = 0.037, OR 1.04 per minute, 95% CI 1.00-1.08) and CBV ASPECTS (p = 0.001, OR 2.11 per ASPECTS point, 95% CI 1.33-3.34) predicted good CS. In similar multivariable models, MTT ASPECTS (p = 0.04, OR 1.46 per ASPECTS point, 95% CI 1.02-2.10) and NCCT ASPECTS predicted good CS (p = 0.003, OR 4.38 per CT ASPECTS point, 95% CI 1.66-11.55) along with longer time from the onset of symptoms to imaging (p = 0.045, OR 1.03 per minute, 95% CI 1.00-1.06 and p = 0.02, OR 1.05 per minute, 95% CI 1.00-1.09, respectively). CBV ASPECTS had a larger area under the receiver operating characteristic curve for good CS (0.837) than NCCT ASPECTS (0.802) or MTT ASPECTS (0.752) at arrival. Conclusions: Favorable CBV ASPECTS, NCCT ASPECTS and MTT ASPECTS are associated with good CS along with more salvageable tissue and longer time from the onset of symptoms to imaging in ischemic stroke patients treated with intravenous thrombolysis.

Optimal thresholds for ischemic penumbra predicted by computed tomography perfusion in patients with acute ischemic stroke treated with mechanical thrombectomy

2017 ◽  
Vol 10 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Katsuharu Kameda ◽  
Junji Uno ◽  
Ryosuke Otsuji ◽  
Nice Ren ◽  
Shintaro Nagaoka ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Cerebral Blood Volume ◽  
Mechanical Thrombectomy ◽  
Ct Perfusion ◽  
Characteristic Curve ◽  
Mean Transit Time ◽  
Area Under The Curve ◽  
Ischemic Penumbra ◽  
Optimal Thresholds

Background and purposeOptimal thresholds for ischemic penumbra detected by CT perfusion (CTP) in patients with acute ischemic stroke (AIS) have not been elucidated. In this study we investigated optimal thresholds for salvageable ischemic penumbra and the risk of hemorrhagic transformation (HT).MethodsA total of 156 consecutive patients with AIS treated with mechanical thrombectomy (MT) at our hospital were enrolled. Absolute (a) and relative (r) CTP parameters including cerebral blood flow (aCBF and rCBF), cerebral blood volume (aCBV and rCBV), and mean transit time (aMTT and rMTT) were evaluated for their value in detecting ischemic penumbra in each of seven arbitrary regions of interest defined by the major supplying blood vessel. Optimal thresholds were calculated by performing receiver operating characteristic curve analysis in 47 patients who achieved Thrombolysis In Cerebral Infarction (TICI) grade 3 recanalization. The risk of HT after MT was evaluated in 101 patients who achieved TICI grade 2b–3 recanalization.ResultsAbsolute CTP parameters for distinguishing ischemic penumbra from ischemic core were as follows: aCBF, 27.8 mL/100 g/min (area under the curve 0.82); aCBV, 2.1 mL/100 g (0.75); and aMTT, 7.30 s (0.70). Relative CTP parameters were as follows: rCBF, 0.62 (0.81); rCBV, 0.83 (0.87); and rMTT, 1.61 (0.73). CBF was significantly lower in areas of HT than in areas of infarction (aCBF, p<0.01; rCBF, p<0.001).ConclusionsCTP may be able to predict treatable ischemic penumbra and the risk of HT after MT in patients with AIS.

scholarly journals Fluid-Attenuated Inversion Recovery Vascular Hyperintensities in Transient Ischemic Attack within the Anterior Circulation

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Bei Ding ◽  
Yong Chen ◽  
Hong Jiang ◽  
Huan Zhang ◽  
Juan Huang ◽  
...  
Keyword(s):  
Transient Ischemic Attack ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Inversion Recovery ◽  
Arterial Stenosis ◽  
Significant Difference ◽  
Fluid Attenuated Inversion Recovery ◽  
Ischemic Attack ◽  
Positive Groups

Purpose. The aim of the present study was to evaluate the relationship of fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVH) with haemodynamic abnormality and severity of arterial stenosis in patients with transient ischemic attack (TIA) of the carotid artery system. Patients and Methods. Consecutive inpatients (N = 38) diagnosed with TIAs of the carotid system in a 4-year period (2014–2017) were retrospectively analysed in our study and divided into FVH-negative and FVH-positive groups based on the presence of FVH sign. Each inpatient had undergone magnetic resonance imaging (MRI) followed by computed tomography (CT) perfusion imaging studies. We investigated the degree of arterial stenosis, number of stenosis, watershed regions, and related CT perfusion indexes, including hypoperfusion regions, mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV). Spearman rank correlation was performed between FVHs score, the degree of arterial stenosis, and CT perfusion indexes with significant difference. Results. Thirty-one patients (81.6%) observed with FVH sign were assigned to the FVH-positive group. The hypoperfusion regions, MTT, and CBF values were significantly different between the FVH-negative group and FVH-positive groups. Spearman correlation analysis showed significant positive correlations between hypoperfusion regions, MTT, and FVHs scores (r = 0.755 and 0.674, respectively, p<0.01); a moderate negative correlation was found between CBF and FVHs scores (r = −0.525, p<0.01), whereas the degree of artery stenosis revealed no significant correlation with FVH scores (r = 0.253, p>0.05). Conclusion. Hyperintense vessels on FLAIR were closely associated with hypoperfused regions, MTT, and CBF values, which indicated that the presence of FVHs could be an important and convenient imaging marker of haemodynamic impairment in patients with TIA.

Abstract TP245: Prediction of Hemorrhagic Transformation in Patients With Acute Ischaemic Stroke and Atrial Fibrillation With Ct Perfusion Aspects Scores

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Qiaoshu Wang ◽  
Yanyan Cao ◽  
Yongbo Zhao ◽  
Louis Caplan
Keyword(s):  
Atrial Fibrillation ◽  
Ischemic Stroke ◽  
Acute Stroke ◽  
Acute Ischemic Stroke ◽  
Roc Analysis ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Operating Characteristics ◽  
Middle Cerebral Artery Infarction

Background and Purpose: Hemorrhage transformation (HT) is common in patients with acute cerebral infarction caused by atrial fibrillation. The prediction of HT is crucial after acute stroke, especially for the patients received vessel recanalization therapy. The Alberta Stroke program early CT score (ASPECTS) is used to estimate early ischemic changes within the MCA territory in the acute stroke setting. Several studies indicated that CT perfusion (CTP) and MR diffusion weighted imaging (DWI) ASPECTS scores was useful to quantify the degree of ischemic brain tissue. Hereby we did the study to explore the association of CT perfusion ASPECTS scores with HT in patients with acute ischemic stroke and atrial fibrillation. Methods: This was a single center retrospective study. All patients with middle cerebral artery infarction and atrial fibrillation from September 2008 to September 2013 were included. MR imaging including DWI and gradient echo sequence (GRE), and CTP were required to identify the HT and determine the scores of CTP- ASPECTS. Demographic and clinical characteristics of the HT positive and negative groups were explored. Results: Fifty-four patients were analyzed, among them twenty-four patients (44%) developed HT. According to logistic regression analysis, mean transit time (MTT), cerebral blood volume (CBV) and DWI-ASPECTS scores were associated with HT ( p = 0.035, 0.044, and 0.020 respectively). The following receiver operating characteristics (ROC) analysis revealed area under the curve of MTT, CBV, CBF and DWI were 0.588, 0.737, 0.687, and 0.841 respectively. CBV-ASPECTS score was found to have medium prediction value of HT among all CTP-ASPECTS parameters. ROC analysis also indicated that CBV-ASPECTS score < 7 was the optimal threshold. Conclusions: CTP-ASPECTS was useful to predict the HT of acute ischemic stroke caused by atrial fibrillation and CBV-ASPECTS score < 7 was the preferable parameter.

Abstract T MP4: Quality of CT Perfusion Imaging Thresholds for Infarct and Penumbra in the Acute Ischemic Stroke Setting: An Updated Systematic Review

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Christopher d'Esterre ◽  
Jonathan Dykeman ◽  
Mohamed Al-mekhlafi ◽  
Petra Cimflova ◽  
Shivanand Patil ◽  
...  
Keyword(s):  
Systematic Review ◽  
At Risk ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Perfusion Imaging ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Infarct Core ◽  
Not At Risk

Background: CT Perfusion (CTP) may inform treatment decisions in acute ischemic stroke (AIS). We sought to determine extent of variability with CTP thresholds for infarct core and penumbra and reasons for such variability using an up-to-date systematic review. Methods: Search strategy combined the themes of AIS, perfusion imaging, and CT/MRI. Two independent reviewers screened at all levels; disagreements were settled through consensus. Inclusion criteria were CTP within 24hrs of stroke onset and reported perfusion thresholds for infarct core, penumbra, and/or normal/not at risk tissue for mixed grey/white matter. Study demographics, QUADAS assessment of quality, and mean thresholds of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), relative CBV (rCBV), relative CBF (rCBF), and relative MTT (rMTT) were collected. Thresholds were reported as median mean threshold (interquartile range). Results: The search resulted in a total of 11919 abstracts from EMBASE and MEDLINE. Of these, 711 studies were identified for full-text review, 134 met all eligibility criteria. 29 studies provided thresholds for CTP and were included in the review. For CBF, median mean threshold was 8.64 (7.94-13.92) ml/min/100g for core, 19.1 (17.1-31.9) ml/min/100g for penumbra and 47.4 (35.6-59.1) ml/min/100g for normal/not at risk tissue. For CBV, median mean threshold was 1.0 (0.68-1.88) ml/100g for core, 2.45 (2.0-3.0) ml/100g for penumbra, and 2.65 (2.0-3.3) ml/100g for normal/not at risk tissue. For MTT median mean threshold was 15.6 (15.3-17.7) seconds for core, 10.5 (7.1-46.2) seconds for penumbra, and 3.9 (3.65-4.15) seconds for normal/not at risk tissue. Median mean threshold for rCBF was 29% (22.5%-35.5%) for core. Sufficient TTP and Tmax data were not reported. Overall, quality was highly variable according QUADAS ranging from 20.7% to 93.1% across the 14 variables. Conclusions: Due to heterogeneity of vendor CTP algorithms, follow-up imaging to define infarct core (NCCT, DWI), unknown recanalization times/reperfusion status and differing onset to CT times, CTP thresholds for infarct core and penumbra are highly variable. As such, a single best threshold for core could not be derived from literature.

CT perfusion and angiographic assessment of pial collateral reperfusion in acute ischemic stroke: the CAPRI study

2016 ◽  
Vol 8 (12) ◽  
pp. 1211-1216 ◽  
Author(s):  
Arturo Consoli ◽  
Tommy Andersson ◽  
Ake Holmberg ◽  
Luca Verganti ◽  
Andrea Saletti ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Univariate Analysis ◽  
Infarct Core ◽  
Intravenous Tissue Plasminogen Activator ◽  
Dichotomous Variable

BackgroundThe purpose of this study was to evaluate the correlation between a novel angiographic score for collaterals and CT perfusion (CTP) parameters in patients undergoing endovascular treatment for acute ischemic stroke (AIS).Methods103 patients (mean age 66.7±12.7; 48.5% men) with AIS in the anterior circulation territory, imaged with non-contrast CT, CT angiography, and CTP, admitted within 8 h from symptom onset and treated with any endovascular approach, were retrospectively included in the study. Clinical, neuroradiological data, and all time intervals were collected. Careggi Collateral Score (CCS) was used for angiographic assessment of collaterals and the Alberta Stroke Program Early CT Score (ASPECTS) for semiquantitative analysis of CTP maps. Two centralized core laboratories separately reviewed angiographic data, whereas CT findings were evaluated by an expert neuroradiologist. Univariate and multivariate analysis were performed considering CCS both as an ordinal and a dichotomous variable.Results37/103 patients (35.9%) received intravenous tissue plasminogen activator. Median (IQR) ASPECTS was 9 (6–10) for admission CT, 9 (5–10) for cerebral blood volume (CBV) maps, 3 (2–3) for mean transit time maps, 3 (2–4), for cerebral blood flow maps, and 5 (3–7) for CTP mismatch. Univariate analysis showed a significant correlation between CCS and ASPECTS for all CTP parameters. Multivariate analysis confirmed an independent association only between CCS and CBV (p=0.020 when CCS was considered as a dichotomous variable, p=0.026 with ordinal CCS).ConclusionsA correlation between angiographic assessment of the collateral circulation and CTP seems to be present, suggesting that CCS may provide an indirect evaluation of the infarct core volume to consider for patient selection in AIS.

Using the Region of Interest from Time-of-Flight Magnetic Resonance Angiography to Differentiate Between Intracranial Arterial Dissection and True Atherosclerotic Stenosis

2019 ◽  
Vol 47 (1-2) ◽  
pp. 8-14 ◽  
Author(s):  
Jung Won Hwang ◽  
Jin-Man Jung ◽  
Jae Hyung Cha ◽  
Il Eok Jung ◽  
Moon Ho Park ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Time Of Flight ◽  
Region Of Interest ◽  
Arterial Stenosis ◽  
Arterial Dissection ◽  
Intracranial Arterial Stenosis ◽  
Tof Mra ◽  
Significant Difference ◽  
Focal Stenosis

Background: Noncontrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) is commonly used to examine intracranial arterial stenosis, although it can be difficult to identify the etiology of the stenosis. Our aim was to determine the effectiveness of 3D TOF MRA in differentiating an intracranial arterial dissection from atherosclerosis. Methods: During 2015–2017, 356 patients had confirmed intracranial arterial stenosis based on high resolution-magnetic resonance imaging. This study ultimately included 51 patients with severe focal stenosis that was caused by dissection and atherosclerosis. We compared the dissection group with the atherosclerotic narrowing group by measuring the region-of-interest (ROI) values 3 mm proximal and 3 mm distal from sites of severe focal stenosis. Results: A significant difference was observed between the median ROI difference values in the dissection group (n = 18) and the atherosclerosis group (n = 33; 35.6 [20.9–78.4] vs. 165.5 [99.8–328.5]; p < 0.001). A receiver operating characteristic curve was prepared to distinguish between dissection and atherosclerosis using the ROI difference values. The area under the curve was 0.919 (sensitivity 75.8%, specificity 94.4%). The optimal cutoff value for using ROI to distinguish between dissection and atherosclerosis was found to be 99.0 based on the Youden’s index. Conclusion: The ROI difference value from 3D TOF MRA could help distinguish between dissection and atherosclerosis. If the ROI difference value from 3D TOF MRA is small (< 99.0), detailed testing should be performed to identify dissection.

Abstract 3268: Ct Perfusion As A Tool To Predict The Risk Of Hemorrhagic Transformation In Ischemic Stroke Treated With Tissue Plasminogen Activator: A Single Center Experience.

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Tareq Kass-Hout ◽  
Maxim Mokin ◽  
Omar Kass-Hout ◽  
Emad Nourollahzadeh ◽  
David Wack ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Stroke ◽  
Brain Tissue ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Intravenous Thrombolysis ◽  
Hemorrhagic Transformation ◽  
Stroke Therapy ◽  
Two Phase ◽  
The Mean

Objective: To use the Computed Tomography Perfusion (CTP) parameters at the time of hospital admission, including Cerebral Blood Volume (CBV) and Permeability Surface area product (PS), to identify patients with higher risk to develop hemorrhagic transformation in the setting of acute stroke therapy with intravenous thrombolysis. Methods: Retrospective study that compared admission CTP variables between patients with Hemorrhagic Transformation (HT) acute stroke and those with no hemorrhagic transformation. Both groups received standard of care intravenous thrombolysis with tPA. Twenty patients presented to our stroke center between the years 2007 - 2011 within 3 hours after stroke symptoms onset. All patients underwent two-phase 320 slice CTP which creates CBV and PS measurements. Patients were divided into two groups according to whether or not they had HT on a follow up CT head without contrast, done within 36 hours of the thrombolysis therapy. Clinical, demographic and CTP variables were compared between the HT and non-HT groups using logistic regression analyses. Results: HT developed in 8 (40%) patients. Patients with HT had lower ASPECT score ( P =.03), higher NIHSS on admission ( P= .01) and worse outcome ( P= .04) compared to patients who did not develop HT. Baseline blood flow defects were comparable between the two groups. The mean PS for the HT group was 0.53 mL/min/100g brain tissue, which was significantly higher than that for the non-HT group of 0.04 mL/min/100g brain tissue ( P <.0001). The mean area under the curve was 0.92 (95% CI). The PS threshold of 0.26 mL/min/100g brain tissue had a sensitivity of 80% and a specificity of 92% for detecting patients with high risk of hemorrhagic transformation after intravenous thrombolysis. Conclusions: Admission CTP measurements might be useful to predict patients who are at higher risk to develop hemorrhagic transformation after acute ischemic stroke therapy.

Sign in / Sign up

Export Citation Format

Share Document