scholarly journals In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0133566 ◽  
Author(s):  
William A. Copen ◽  
Livia T. Morais ◽  
Ona Wu ◽  
Lee H. Schwamm ◽  
Pamela W. Schaefer ◽  
...  
Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Simon Morr ◽  
Maxim Mokin ◽  
Ashish Sonig ◽  
Kenneth Snyder ◽  
Adnan Siddiqui ◽  
...  

Introduction: Tools for evaluating risk of post-intervention risk hemorrhage in the setting of acute stroke include a noncontrast head CT based Alberta Stroke Program Early CT score (ASPECTS) and contrasted CT based perfusion plots. The correlation between these parameters is unknown. Methods: We performed a retrospective analysis of a prospectively collected endovascular stroke database of patients with M1 middle cerebral artery occlusion who underwent endovascular recanalization. We reviewed admission preintervention noncontrast CT for Alberta Stroke Program Early CT score (ASPECTS) and 320-detector row whole brain CT perfusion parameters (Cerebral blood volume and time to peak). Pearson correlation was determined between cerebral blood volume on the side of the stroke and ASPECTS. Results: ASPECTS and CT perfusion map were identified in 45 and 43 patients respectively. Statistically significant correlation was found between ASPECTS and cerebral blood volume data on CT perfusion MAP. (p=0.034, r=-0.28). The correlation coefficient is very weak. No correlation could be found between time to peak and ASPECTS. Conclusion: A statistically significant, but weak correlation exists between ASPECTS and CBV. Further research is needed to assess the physiological meaning of diverse imaging modalities utilized in the acute stroke setting.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Maxim Mokin ◽  
Elad Levy ◽  
Jeffrey L Saver ◽  
Mayank Goyal ◽  
Alain Bonafe ◽  
...  

Background and purpose: Advanced CT perfusion (CTP) imaging can estimate the size of the ischemic core, which can be used for selection of patients for endovascular therapy. The relative cerebral blood volume (rCBV) and cerebral blood flow (rCBF) thresholds chosen to identify ischemic core influence the accuracy of prediction. The purpose of this study was to analyze the accuracy of various rCBV and rCBF thresholds for predicting 27 hour infarct volume using RAPID automated analysis software. Methods: Patients from the SWIFT PRIME study with baseline and 27 hour follow-up CT perfusion scans were included if they had complete reperfusion based on Tmax>6s perfusion maps obtained at 27 hours. Patients from both the tPA and endovascular groups were included. Infarct volume was determined on MRI (FLAIR images) or CT scans obtained 27 hours after symptom onset. The predicted ischemic core volume on rCBV and rCBF maps using thresholds ranging between 0.2 and 0.8 was compared with the actual infarct volume to determine the most accurate thresholds. Results: Among the 47 subjects, the following baseline CTP thresholds most accurately predicted the actual 27 hour infarct volume: rCBV=0.34 (Median absolute error (MAE)=11.5 ml); rCBV=0.36, MAE=9.9 ml; rCBV=0.4, MAE=12.5 ml; rCBF=0.3, MAE=8.8 ml; rCBF=0.32, MAE=7.3; and rCBF=0.34, MAE=7.8. Conclusions: Brain regions with rCBF ≤ .32 or rCBV ≤ .36 provided the most accurate prediction of infarct volume in patients who achieved complete reperfusion with median absolute errors less than 10 ml. Our data support the value of automated image analysis software as a tool for accurate prediction of ischemic core lesion volume.


2012 ◽  
Vol 36 (5) ◽  
pp. 1083-1087 ◽  
Author(s):  
Amy R. deIpolyi ◽  
Ona Wu ◽  
Eric A. Macklin ◽  
Pamela W. Schaefer ◽  
Lee H. Schwamm ◽  
...  

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Tareq Kass-Hout ◽  
Maxim Mokin ◽  
Omar Kass-Hout ◽  
Emad Nourollahzadeh ◽  
David Wack ◽  
...  

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.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Waimei A Tai ◽  
Archana Purushotham ◽  
Matus Straka ◽  
Rebecca M Sugg ◽  
Naveed Akhtar ◽  
...  

Introduction: The use of mismatch between the ischemic core and penumbra to select patients who are likely to benefit from acute stroke therapy has gained popularity. Interpretation of the ischemic core and penumbra on standard CT-perfusion (CTP) maps is subjective. This may lead to variability among physicians in the decision if a patient is a good candidate for acute stroke therapy. A CTP-Mismatch map with outlines of the ischemic core and penumbra could limit this variability. The goal of this study was to determine if inter-observer agreement regarding a patient’s suitability for acute stroke therapy improves with the use of a CTP-Mismatch map. The figure shows a typical CTP-Mismatch map. Methods: Ninety-six consecutive patients evaluated with CTP prior to intra-arterial therapy at St. Lukes Hospital in 2008-09 were included. 79 patients had adequate quality CTP for this analysis. Standard CTP maps (CBV, CBF, MTT, and Tmax) and a CTP-Mismatch map were generated with a fully automated program for processing of CTP source images (RAPID). RAPID assessed the ischemic core using a CBF threshold <30% of the contralateral hemisphere (rCBF<30%). The ischemic penumbra was defined by a Tmax threshold of >6 sec (Tmax>6s). The standard CTP maps and the CTP-Mismatch map were independently analyzed by two vascular neurologists in a blinded fashion. The raters assessed a patient's suitability for intra-arterial therapy based on the following mismatch criteria: (1) a ratio between (Tmax>6s) and (rCBF<30%) volumes >1.8 and (2) an absolute difference between (Tmax>6s) and (CBF<30%) volumes >15ml. Interobserver reliability was assessed with Cohen’s kappa. Results: When assessment of suitability for intra-arterial therapy was based on interpretation of standard CTP maps, the two raters agreed in 58 of 79 patients (kappa=0.46; 95% CI=0.24-0.60). The agreement between observers improved when suitability was determined using CTP-Mismatch maps (agreement in 76 of 79 cases; kappa=0.92; 95% CI=0.75-0.92; p<0.001 for difference between kappa values). The 3 cases with inter-observer disagreement had artifact on the CTP-Mismatch map. Following concensus adjudication of these 3 cases, 40 of the 79 patients (51%) were deemed suitable candidates for acute stroke therapy. Conclusion: CTP-Mismatch maps with estimates of ischemic core and penumbra volumes markedly improve inter-observer agreement regarding assessment of suitability for acute stroke therapy. Such maps, which can be generated automatically, may help standardize decision making algorithms for evaluation of potential intra-arterial therapy candidates.


2014 ◽  
Vol 25 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Junya Aoki ◽  
Yohei Tateishi ◽  
Christopher L. Cummings ◽  
Esteban Cheng-Ching ◽  
Paul Ruggieri ◽  
...  

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sundeep Saini ◽  
Steven Warach ◽  
Marie Luby ◽  

Objectives: Hemorrhagic transformation of the ischemic lesion is a common thrombolytic complication when treating acute stroke patients with standard IV-tPA. In a retrospective study we demonstrated that patients that have HT post-thrombolysis have a significantly lowered cerebral blood volume (CBV) on their pre-thrombolysis MRI compared to non HT patients. The objective of this study was to determine prospectively whether reduced CBV in combination with stroke severity can predict the occurrence of HT in patients post-thrombolysis. Methods: Patients were selected from the NINDS Stroke Registry if they: had an acute ischemic stroke located in the MCA territory, were treated with standard IV-tPA, had a pre-treatment MRI with evaluable DWI and PWI, and had post-treatment MRI evaluation for HT. A rater calculated CBV maps in PMA™ (ASIST-Japan) and performed image registration and region of interest analyses in MIPAV™ (NIH). The rater repeated the CBV analysis without image registration using DICOM software available on the scanner. Multinomial regression with covariates of baseline NIHSS, DWI lesion size, and CBV ratio was performed. All MRI scans were reviewed by expert readers blinded to the CBV analyses to determine the presence of HT using the ECASS-II criteria. Results: Seventy-six patients met the study criteria with a mean (SD) age of 68.1 (±14.1) years, median baseline NIHSS of 12 (IQR25-75: 5-18) and median onset to first MRI of 109 minutes (IQR25-75: 82-157). Thirty-six percent of patients (27/76) were positive for HT post-thrombolysis. The mean CBV ratio was 0.25 (STD ± 0.23) in the positive HT patients compared to 0.55 (STD ±0.24) in the negative HT patients. Multinomial regression demonstrated that the CBV ratio < 0.5 (p<0.006) and baseline NIHSS > 15 (p<0.034) significantly predicted the occurrence of any HT. The CBV ratio < 0.5 was the only independent predictor of severe HT, PH1 or PH2 (p<0.008). DWI lesion size using > 100 ml involvement of the MCA territory was not significant in predicting any or severe HT. Conclusions: Pre-treatment CBV ratio used in combination with baseline NIHSS are promising predictors of HT after standard IV-tPA. The ability to calculate CBV ratios directly on the scanner supports usage in acute intervention decision making.


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