SUMMARY

CTP and MRP imaging of the brain is not only feasible, but offers clinically relevant physiologic data not obtainable by conventional CT or MR imaging. In untreated gliomas, CBV imaging has a high negative predictive value; the absence of elevated blood volume may effectively exclude high-grade tumor, regardless of the enhancement characteristics of the lesion. For post-treatment brain tumors, the situation is more complex, but there is good evidence that perfusion imaging has advantages over both conventional MR imaging and other functional imaging techniques. In neurovascular diseases, CTP and MRP techniques facilitate detection of ischemic tissue with reduced CBF or CBV, therefore potentially helping to determine tissue at risk for infarction if circulation is not improved.