Imaging‐based patient selection for intra‐arterial stroke therapy

Acute ischemic strokes arising from blockages of the major brain-supplying arteries put patients at risk for extensive brain injury. Left untreated, these major strokes produce significant disability and death. Fortunately, recent advances in stroke devices have improved clinical outcomes in such patients, provided that they are treated early enough after their stroke onset. Using minimally invasive techniques, these devices are delivered through the arteries using catheters in order to remove the thrombus, or blood clot, that is blocking blood flow to the brain. However, further progress is needed, as approximately half of the major stroke patients who are treated in this way remain dependent or dead at 3 months after their stroke. In particular, a better understanding of which patients are likely to benefit from intervention is crucial. This thesis investigates the role of brain imaging to improve patient selection. Part I examines the use of various imaging approaches to identify those stroke patients who have already suffered large areas of brain injury, and as a result are unlikely to do well after treatment. Excluding such patients will improve the risk-benefit profile of stroke intervention and make treatment more cost effective. Part II explores the emerging field of thrombus imaging and the impact of thrombus characteristics on outcomes after intervention. Through this work, advances in stroke devices and procedural techniques can be targeted to the most difficult to treat thrombi. The thesis concludes with a discussion of the key research questions on the horizon.