Diagnostic Accuracy of Cerebral CT Perfusion in Acute Ischemic Stroke

Asim Shaukat; Nosheen Ahmad; Amir Shaukat

doi:10.29054/apmc/2015.339

Asim Shaukat Associate Professor Department of Radiology PMC / Allied Hospital, Faisalabad
Nosheen Ahmad Senior Registrar, Radiology PMC / Allied Hospital, Faisalabad
Amir Shaukat Professor of Medicine PMC / DHQ Hospital, Faisalabad

DOI: https://doi.org/10.29054/apmc/2015.339

Keywords: Acute ischemic stroke, Diffusion MRI, CT perfusion imaging

Abstract

Objectives: To determine the diagnostic accuracy of CT Perfusion brain over Non contrast CT for patients presenting with stroke symptoms in the 12-hour window. Design: Cross-sectional study. Setting: Department of Radiology Allied Hospital, Faisalabad. Period: From July 2014 to December 2014 Patients and Method: We studied 60 patients of 45-70 years of age of both genders (mean 55.13±5.54) (42 (70%) males and 18 (30%) females) with initial clinical symptoms suggestive of acute ischemic stroke. All patients had an initial non-contrast head CT, CT Perfusion (CTP), and follow up brain diffusion MRI at 7th day. The obtained CT perfusion images were used for image processing. Cerebral blood volume, cerebral blood flow and mean transit time were visually estimated and manually traced and the results were compared to diffusion MRI lesions. Results: Follow-up DWI for confirmation of

acute infarct revealed true recent infarcts in 36 patients. NCCT revealed 23 (38.3%) true acute infarcts, 10 (16.7%) false positive infarcts, 14 (23.3%) true negative and 13 (21.7%) false negative yielding diagnostic accuracy of 61.66%. CTP revealed 30 (50%) true positive acute infarcts with two (3.3%) false positive, 22 (36.7%) true negative and 6 (10%) false negative yielding sensitivity of 83.3%, specificity of 91.67%, PPV=93.75%, NPV=78.57% and diagnostic accuracy of 86.7%. CTP was significantly more sensitive (83.3 vs. 64.2%, p < 0.0001) and accurate (86.7 vs. 61.7%, p < 0.0001) and had a better negative predictive value (78.57 vs. 52.2%) than NCCT. Conclusions: Dynamic PCT provides more sensitivity and accuracy than no enhanced CT in detecting acute strokes in the 12-hour window.