Blake D. Murphy, Presenter: Nothing to Disclose

Xiaogang Chen PhD, Abstract Co-Author: Nothing to Disclose

Ting-Yim Lee PhD, Abstract Co-Author: Nothing to Disclose

Allan J. Fox MD, Abstract Co-Author: Nothing to Disclose

D James Sahlas MD, Abstract Co-Author: Nothing to Disclose

Matthew Hogan MD, Abstract Co-Author: Nothing to Disclose

Sandra Black MD, Abstract Co-Author: Nothing to Disclose

Mayank Goyal MD, Abstract Co-Author: Nothing to Disclose

Andrew M Demchuk MD, Abstract Co-Author: Nothing to Disclose

Shelagh B Coutts MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

In this study we determined thresholds of cerebral blood flow (CBF) and cerebral blood volume (CBV) for differentiating between penumbral and infarcted tissue in acute stroke patients.

Twenty-four patients were enrolled in this study and all received a non-enhanced CT (NECT) head scan and a contrast-enhanced CT Perfusion (CTP) scan 150ml/min/100g or CBV > 8.0 ml/100g. CBF and CBV values were obtained from admission CTP scan for the following regions: Infarct (regions that progressed to infarction on 5-7 day follow-up NECT); Penumbra (CBF < 25 ml/min/100g on admission that did not progress to infarction) and Contralateral (values from contralateral region). Discriminant analysis was used to determine thresholds for infarction using CBF and CBV independently. Additionally, these thresholds were combined to identify infarct.

CBF values in penumbra (27.2 ± 4.15 ml/min/100g) were significantly higher than infarct (15.3 ± 3.76 ml/min/100g) and significantly lower than contralateral values (43.9 ± 6.36 ml/min/100g). CBV in the penumbra (2.23 ± 0.33 ml/100g) was significantly higher, and CBV in the infarct (1.24 ± 0.29 ml/100g) was significantly lower, than contralateral values (1.93 ± 0.26 ml/100g). Discriminant analysis resulted in a threshold for infarction of CBF equal to 21.6 ml/min/100g, with a sensitivity of 87.8% and specificity of 83.7%. Analysis with CBV as the discriminating factor resulted in a threshold of 1.76 ml/100g and corresponding sensitivity of 86.6%, and specificity of 89.8% for infarction. By combining both CBF and CBV thresholds, specificity was increased (95.9%), while sensitivity was moderately decreased (79.3%).

CBV and CBF parameters obtained with CT Perfusion can differentiate between penumbra and infarct in acute stroke patients with a high degree of sensitivity and specificity for infarction. This work was supported by the Canadian Stroke Network.

T.L.: TY Lee is a consultant to General Electric Healthcare on CT Perfusion.

Murphy, B, Chen, X, Lee, T, Fox, A, Sahlas, D, Hogan, M, Black, S, Goyal, M, Demchuk, A, Coutts, S, et al, , Thresholds of CT Perfusion Parameters for Differentiating between Infarct and Penumbra in Acute Ischemic Stroke.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4418659.html