Leticia C.S. Souza MD, Presenter: Nothing to Disclose

Seyedmehdi Payabvash MD, Abstract Co-Author: Nothing to Disclose

Shervin Kamalian MD, Abstract Co-Author: Nothing to Disclose

Karen Furie, Abstract Co-Author: Nothing to Disclose

Ramon Gilberto Gonzalez MD, PhD, Abstract Co-Author: Research grant, Penumbra, Inc

Michael H. Lev MD, Abstract Co-Author: Advisory Board, General Electric Company Research support, General Electric Company Advisory Board, CoAxia, Inc Consultant, Vernalis plc Consultant, Takeda Pharmaceutical Company Limited

Recent studies suggest that admission DWI scans may help to identify stroke patients at increased risk for HT; infarct volume on the admission DWI is considered an independent predictor. We determined the value of admission CTP-based volume of hypoperfused cerebral tissue in prediction of HT.

Patients with ischemic stroke were included in this study if they had both CTP and DWI scans within 9 hours of symptom onset and underwent either CT or MRI follow-up within 5 days to determine HT. Volumetric assessment of the DWI lesion was performed by manual segmentation on admission scans. CTP maps were coregistered to the standard brain space MNI-152 and voxel-based values were calculated. We determined the hypoperfused tissue volume of the ischemic hemisphere using relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV) voxel values below thresholds ranging from 0.1 - 0.7 in 0.02 intervals, as well as that of relative mean transit time (rMTT) above thresholds ranging from 1.3 - 2.8 in 0.05 intervals. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was used to evaluate of the accuracy of each set of volumes in prediction of HT.

Ninety six patients were included in our analysis. Of those, 22 (23%) showed HT on follow-up scan. Multivariate logistic regression analysis showed that the infarct core tissue volume on DWI scans, as well as the admission NIHSS score are independent predictors of HT. Based on separate ROC analyses, the volume of hypoperfused tissue with rCBF below 0.48 in the ischemic hemisphere (AUC=0.73) and rMTT above 1.3 (AUC=0.70), could best predict HT in our cohort; this showed a trend towards being slightly more accurate than DWI-based volume (AUC=0.68, p=0.21 vs. rCBF, and p=0.10 vs. rMTT). Patients with HT had significantly larger average hypoperfused volumes using both rCBF< 0.48 (75.2 ± 6.9 vs. 53.6 ± 5.0 mL, p=0.033) and rMTT> 1.3 (118.5 ± 10.0 vs. 89.5 ± 6.9 mL; p=0.041) compared to those without HT.

The hypoperfused tissue volume on admission CTP scans can predict HT risk in stroke with comparable accuracy to DWI infarct volume. This could be of value in making acute management decisions that require reliable estimation of infarct core in patients with contraindication to MRI.

Identifying predictors of HT would facilitate efforts to extend the thrombolytic therapy beyond current therapeutic window

Souza, L, Payabvash, S, Kamalian, S, Furie, K, Gonzalez, R, Lev, M, Volume of Hypoperfused Cerebral Tissue on Admission CTP Can Predict Risk of Hemorrhagic Transformation (HT) in Acute Stroke Patients with Comparable Accuracy to DWI.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9011955.html