Evaluating the Resistance Index in Transcranial Doppler to Detect Brain Blood Flow Response in Patients with Carotid Artery Narrowing or Blockage

What this Trial Is About

Researchers are studying patients with significant stenosis or occlusion of the cervical internal carotid artery to determine a simpler way to identify those at high risk of stroke who might benefit from carotid revascularization. The study focuses on evaluating the diagnostic performance of the resistance index RI measured by transcranial Doppler ultrasound as a quick method to predict cerebral vasoreactivity, which is currently assessed by a more complex and time-consuming standard test. Participants will undergo transcranial Doppler ultrasound to measure the resistance index RI on the middle cerebral artery. This test will be compared to a pharmacological cerebral vasoreactivity test considered the reference standard. Patients will be assessed for differences in RI between the arteries on the side of the carotid lesion and the opposite side to detect normal or altered vasoreactivity. The study aims to reserve the more time-consuming cerebral vasoreactivity test only for patients likely to have impaired vasoreactivity. During the study, participants will receive transcranial Doppler tests in a randomized order and be monitored for cerebral vasoreactivity using the reference standard. Researchers will measure the specificity, sensitivity, positive and negative predictive values of the RI difference to detect normal vasoreactivity. Additional measures include correlations with other Doppler indices. The study involves informed consent, insurance plan membership, and excludes certain conditions such as pregnancy or inability to consent. The study is expected to complete by June 2029.

Diagnostic Performance of the Resistance Index (RI) for the Assessment of Cerebral Vasoreactivity in Transcranial Doppler