Improving acute stroke management with computed tomography perfusion: a review of imaging basics and applications.

The inclusion of dynamic contrast-enhanced computed tomography (CT) or CT perfusion (CTP) scan into the imaging workup for acute stroke patients is widespread. Along with vessel occlusion status from CT angiography, CTP provides pathophysiological information a non-contrast CT cannot provide during the hyperacute stages of cerebral ischemia. Measurement of parenchymal perfusion at the capillary level can be used to characterize tissue viability, a target for thrombolysis. Further, CTP is useful for the detection of blood brain barrier disturbances with the permeability surface area product parameter (PS). Although new to stroke imaging, PS has diagnostic and prognostic implications for primary hemorrhage and secondary hemorrhagic transformation of ischemic stroke. The purpose of this article is to provide an overview of the CTP imaging concepts and their uses for imaging in stroke.