Stroke/cerebral perfusion CT: Technique and clinical applications

Perfusion computed tomography (PCT) has revolutionized CT imaging, broadened its applications, and provided important adjuncts to existing evaluation modalities. The fundamental principle of PCT is that iodinated contrast flow follows blood flow through the brain, entering in the arterial phase, disseminating through tissues in the capillary phase, and exiting the brain via the venous system. Factors affecting blood flow in or out of brain tissues will similarly affect contrast flow through the system. PCT is used extensively in evaluation of acute ischemic stroke patients for improved stroke diagnosis, assessment of core infarction and viable but hypoperfused tissue (penumbra), but also for vasospasm, tumors, and traumatic brain injury.