Overview of imaging in colorectal cancer

Accurate staging of colorectal carcinoma (CRC) at initial diagnosis is critical for proper management of this disease. Computed tomography (CT) is often used for preoperative staging and is complementary to the clinical assessment of the patient and to the use of other imaging techniques, such as endoluminal ultrasound (US). CT can identify those patients who may benefit from local radiation therapy, hepatic resection or cryoablation, or intra-arterial chemotherapy. Endoluminal US may detect patients with early disease and alter their course of therapy, especially in those with rectal carcinoma in which limited surgery might be performed. CT is generally the modality of choice for imaging the postoperative patient. CT clearly depicts the operative area, particularly after abdominoperitoneal resection, and can be used to guide percutaneous biopsy of masses. The role of magnetic resonance imaging in CRC remains to be defined. In this review, we discuss the current roles of these various imaging modalities in the management of this disease.