Functional CT imaging in oncology.

The two-compartment pharmacokinetics exhibited by iodinated contrast media makes these agents well suited to the study of tumour angiogenesis in which new vessels are not only produced in greater number but also are abnormally permeable to circulating molecules. The temporal changes in contrast enhancement of tumours on CT have been shown to correlate with histopathological assessments of angiogenesis with the intravascular and extravascular phases of contrast enhancement reflecting microvessel density and vascular permeability, respectively. By quantifying tumour contrast enhancement to capture physiological information about the vascular system, functional CT can provide a useful adjunct to the anatomical information afforded by MDCT in oncology, aiding with tumour diagnosis, risk stratification and therapy monitoring. By simultaneously assessing tumour vascularity and metabolic demand, the broader expansion of integrated MDCT/PET imaging will support highly sophisticated assessments of tumour biology within a single examination.