Lower gastrointestinal tract tumours: diagnosis and staging strategies

In patients with colorectal cancer, accurate assessment of tumour extent within and beyond the bowel wall and detection of lymph node and distant metastases are of paramount importance in planning the surgical approach, in deciding whether neo-adjuvant chemotherapy or radiation therapy is necessary, and in determining the risk of tumour recurrence and overall prognosis. The utility of MDCT, MR, transrectal ultrasound, PET, PET/CT is discussed and recommendations for cost-effective imaging in these patients are presented.