Tumour angiogenesis and its relation to contrast enhancement on computed tomography: a review.

Angiogenesis describes the formation of new blood vessels within tumours. The process is essential for tumour growth and metastasis. The development of new vessels leads to physiological changes, specifically increased perfusion, blood volume and capillary permeability, that alter contrast enhancement during computed tomography (CT). Functional CT techniques that quantify these physiological changes can provide greater insight into how angiogenesis alters contrast enhancement in routine practice and also serve as diagnostic tools in their own right. The functional information obtained can aid with tissue characterisation, such as type or grade of tumour, improve the detection of hepatic metastases, produce clearer delineation of tumours with benefits for radiotherapy planning and biopsy, and provide prognostic information. By providing a marker for tumour angiogenesis, quantitative contrast enhanced CT can improve the diagnostic assessment of patients with cancer.