Comparison of Perfusion Computed Tomography and Computed Tomography Angiography Source Images with Perfusion-weighted Imaging and Diffusion-weighted Imaging in Patients with Acute Stroke of Less Than 6 Hours' Duration

Background And Purpose: We aimed to determine the diagnostic value of perfusion computed tomography (PCT) and CT angiography (CTA) including CTA source images (CTA-SI) in comparison with perfusion-weighted magnetic resonance imaging (MRI) (PWI) and diffusion-weighted MRI (DWI) in acute stroke <6 hours.

Methods: Noncontrast-enhanced CT, PCT, CTA, stroke MRI, including PWI and DWI, and MR angiography (MRA), were performed in patients with symptoms of acute stroke lasting <6 hours. We analyzed ischemic lesion volumes on patients' arrival as shown on NECT, PCT, CTA-SI, DWI, and PWI (Wilcoxon, Spearman, Bland-Altman) and compared them to the infarct extent as shown on day 5 NECT.

Results: Twenty-two stroke patients underwent CT and MRI scanning within 6 hours. PCT time to peak (PCT-TTP) volumes did not differ from PWI-TTP (P=0.686 for patients who did not undergo thrombolysis/P=0.328 for patients who underwent thrombolysis), nor did PCT cerebral blood volume (PCT-CBV) differ from PWI-CBV (P=0.893/P=0.169). CTA-SI volumes did not differ from DWI volumes (P=0.465/P=0.086). Lesion volumes measured in PCT maps significantly correlated with lesion volumes on PWI (P=0.0047, r=1.0/P=0.0019, r=0.897 for TTP; P=0.0054, r=0.983/P=0.0026, r=0.871 for CBV). Also, PCT-CBV lesion volumes significantly correlated with follow-up CT lesion volumes (P=0.0047, r=1.0/P=0.0046, r=0.819).

Conclusions: In hyperacute stroke, the combination of PCT and CTA can render important diagnostic information regarding the infarct extent and the perfusion deficit. Lesions on PCT-TTP and PCT-CBV do not differ from lesions on PWI-TTP and PWI-CBV; lesions on CTA source images do not differ from lesions on DWI. The combination of noncontrast-enhanced CT (NECT), perfusion CT (PCT), and CT angiography (CTA) can render additional information within <15 minutes and may help in therapeutic decision-making if PWI and DWI are not available or cannot be performed on specific patients.