CT perfusion (CTP) has been applied increasingly in research of ischemic stroke. However, in clinical practice, it is still a relatively new technology. For neurologists and radiologists, the challenge is to interpret CTP results properly in the context of the clinical presentation. In this article, we will illustrate common CTP patterns in acute ischemic stroke using a case-based approach. The aim is to get clinicians more familiar with the information provided by CTP with a view towards inspiring them to incorporate CTP in their routine imaging workup of acute stroke patients.
Cytidine Triphosphate ; Humans ; Perfusion ; Stroke

BACKGROUND AND PURPOSE: Non-contrast brain computed tomography (NCCT) remains the most common imaging modality employed to select patients for thrombolytic therapy in acute ischemic stroke. The current study used the Alberta Stroke Program Early CT Score (ASPECTS) to identify early ischemic changes on brain NCCT imaging with the aim to investigate whether a relationship exists between time from symptoms onset to NCCT with the presence of early ischaemic change quantified by ASPECTS. METHODS: We studied 1,329 ischemic stroke patients who had NCCT within 8 hours of stroke onset. Patients were assessed to see if they had any ASPECTS lesion and if the rate of patients with a lesion increased with time using logistic regression. RESULTS: 30% patients had an ASPECTS < 10 within the first 3 hours from symptom onset. Within the first 3 hours, the odds for a CT change (ASPECTS < 10) per minute of time was 1.00 with 95% confidence interval (CI) (0.99 to 1.00) (P=0.266). After 3 hours, there was a significant increase in odds of ASPECTS < 10 with increasing time. The odds of being ASPECTS positive increased 1% (odds ratio=1.01) per 1 minute of time with 95% CI (1.00 to 1.01) (P=0.002). CONCLUSIONS: We have identified that prior to first 3 hours of stroke there was no effect of time on odds of CT ischemic change; after the first 3 hours of stroke the odds increased with increasing time to CT scan. The occurrence of early ischemic change may be a marker of time from stroke onset rather than severity.
Alberta ; Brain ; Humans ; Logistic Models ; Stroke* ; Thrombolytic Therapy ; Tomography, X-Ray Computed