CT Perfusion Imaging and CASI

Perfusion computed tomography (CT) allows functional evaluation of tissue vascularity. It measures the temporal

changes in tissue density after intravenous injection of a contrast medium (CM) bolus using a series of dynamically

acquired CT images. The greatest impact of perfusion CT has been on the assessment of patients who have had

strokes, wherein the rapid scan timing and faster image processing have cemented its role as the modality of choice

for evaluation of structural and functional status of cerebral vasculature.1 In the field of oncology, perfusion CT has found

applications in diagnosis, staging, prognostic evaluation and monitoring of response to therapies.Although the

role of ultrasound and magnetic resonance imaging have been explored for perfusion, there is a linear relationship

between iodine concentration and density changes seen on CT expressed as Hounsefield units (HU), hence CT may be

regarded as a preferred technique for perfusion imaging in general. Perfusion CT also has the potential to become the

preferred technique for the assessment of tumor response to antiangiogenic drugs