Perfusion CT imaging of colorectal cancer

Abstract

Imaging plays an important role in the assessment of colorectal cancer, including diagnosis, staging, selection of treatment, assessment of treatment response, surveillance and investigation of suspected disease relapse. Anatomical imaging remains the mainstay for size measurement and structural evaluation; however, functional imaging techniques may provide additional insights into the tumour microenvironment. With dynamic contrast-enhanced CT techniques, iodinated contrast agent kinetics may inform on regional tumour perfusion, shunting and microvascular function and provide a surrogate measure of tumour hypoxia and angiogenesis. In colorectal cancer, this may be relevant for clinical practice in terms of tumour phenotyping, prognostication, selection of individualized treatment and therapy response assessment.

Figure 1.

Typical perfusion CT acquisition protocol for cancer. IV, intravenous.

Figure 2.

Typical enhancement time curves. PE, peak enhancement; TTP, time to peak enhancement.

Figure 3.

Parameters obtained from kinetic modelling. F, front.

Figure 4.

Perfusion CT characteristics of the normal rectum (a) compared with a cancer (b).

Figure 5.

Different patterns of vascularization within the tumour.

Figure 6.

Different patterns of vascularization and metabolism within the tumour.

Figure 7.

Decrease in vascularization of the primary tumour before (a) and after (b) chemoradiation. F, front.