Computed Tomography Perfusion (CTP) to Predict Response to Recanalization in Ischemic Stroke Project (CRISP)

Computed Tomography Perfusion (CTP) to Predict Response to Recanalization in Ischemic Stroke Project

The overall goal of the CTP to predict Response to recanalization in Ischemic Stroke Project (CRISP) is to develop a practical tool to identify acute stroke patients who are likely to benefit from endovascular therapy.

The project has two main parts. During the first part, the investigators propose to develop a fully automated system (RAPID) for processing of CT Perfusion (CTP) images that will generate brain maps of the ischemic core and penumbra. There will be no patient enrollment in part one of this project.

During the second part, the investigators aim to demonstrate that physicians in the emergency setting, with the aid of a fully automated CTP analysis program (RAPID), can accurately predict response to recanalization in stroke patients undergoing revascularization. To achieve this aim the investigators will conduct a prospective cohort study of 240 consecutive stroke patients who will undergo a CTP scan prior to endovascular therapy. The study will be conducted at four sites (Stanford University, St Luke's Hospital, University of Pittsburgh Medical Center, and Emory University/Grady Hospital). Patients will have an early follow-up MRI scan within 12+/-6 hours to assess reperfusion and a late follow-up MRI scan at day 5 to determine the final infarct.

Inclusion Criteria:

1. be 18 or older;
2. have a clinical diagnosis of ischemic stroke and a score of 5 or more points on the NIHSSS;
3. be scheduled to undergo intraarterial (IA) therapy for acute hemispheric stroke (either as primary therapy or as adjuvant therapy following intravenous tPA treatment);
4. be scheduled to have a standard CT including perfusion imaging and CT angiography of the circle of Willis (CTA) prior to IA therapy;
5. begin intra-arterial thrombectomy within 90 minutes of completion of the CT scan and within 18 hours of symptom onset. (Start of IA therapy is defined as the time of insertion of the femoral artery sheath; Time of brain scan is defined as the time that the scan is completed); and
6. have provided informed consent.

Exclusion Criteria:

1. have any pre-existing illness resulting in a modified Rankin Scale Score of 3 or higher prior to the qualifying stroke;
2. are pregnant.