ABSTRACT
Perfusion CT uses a conventional contrast medium to depict the physiology of the cerebrovascular system. The range of physiological parameters that can be assessed and quantified reflects the pharmacokinetics of the contrast media (Table 6.1). After intravenous injection, contrast medium initially is distributed within the vascular space allowing measurement of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT). As time passes, contrast medium may pass into the extravascular space allowing the integrity of the blood-brain barrier (BBB) and the relative extravascular volume (REV) to be evaluated. This chapter provides an overview of cerebrovascular physiology and describes how cerebrovascular physiology is altered in a range of pathological states relevant to the application of perfusion CT.
