Application Value of CT Perfusion Imaging in Patients with Posterior Circulation Hyperacute Cerebral Infarction

Abstract

Objectives: This study aims to evaluate the application value of computed tomography perfusion (CTP) imaging in patients with posterior circulation cerebral infarction in the hyperacute phase. Methods: The changes in CTP parameters, such as time to peak (TTP), mean transfer time (MTT), cerebral blood flow (CBF) and the cerebral blood volume (CBV) of ischemic region, as well as the ischemic penumbra, infarction core at the affected side and normal brain tissue at the uninjured side, of 168 patients with suspected posterior circulation acute ischemic stroke were analyzed. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of each parameter map of CTP in displaying the cerebral infarction size in each part of the posterior circulation were evaluated. Results: The CTP results revealed that CBF and CBV in the infarction area significantly decreased, and MTT and TTP in the blood supply area of cerebellum, thalamus and posterior cerebral artery (PCA) were significantly delayed. These were statistically different from those in the surrounding penumbra and normal brain tissue (P < 0.05). Furthermore, the CBF of the penumbra in each part slightly decreased, and the delay of MTT and TTP was statistically different from that in normal brains (P < 0.05). The CBV of the penumbra in the pons, midbrain and thalamus decreased, which was statistically different from that in normal brain tissue and simple cerebral ischemia tissue (P < 0.05). The changes in CBF and MTT of the simple cerebral ischemia in each part, and TTP, except for the cerebellum, were statistically different from those of cerebral infarction and normal brain tissue (P < 0.05). The total sensitivity, specificity and accuracy for the posterior circulation cerebral infarction was 77.2%, 98.6% and 94.9%, respectively, according to the CTP evaluation. Conclusion: The CTP parameter map can reflect the difference between an ischemic penumbra and an infraction core in the posterior circulation. It has high sensitivity, specificity and accuracy in the CTP evaluation of posterior circulation cerebral infarctions.