Background and objective: Colonoscopy is the procedure of choice for the diagnosis of colorectal neoplasms. CT colonography (CTC), a recently developed minimal invasive radiological technique, permits the identification of colorectal tumors. The aim of the present study was to evaluate the efficacy of CTC in the detection of colorectal polyps, and to establish the factors determining a diagnostic accuracy.
Patients and method: Patients with colorectal polyps admitted for endoscopic polypectomy were included. CTC was performed prior to colonoscopy in all patients. Demographic and clinical data were registered, as well as the polyp characteristics. Efficacy of CTC was analyzed with respect to each individual polyp and each patient.
Results: Colonoscopy identified 87 colorectal polyps in 30 patients. CTC had a sensitivity of 70% for the detection of polyps of any size, being 92%, 73% and 55% for polyps > or = 10 mm, 5-9 mm and < or = 4 mm, respectively. On the other hand, the sensitivity of CTC for the detection of pedunculated, semipedunculated and sessile polyps was 85%, 92% and 56%, respectively. Accuracy of CTC was associated with polyp size (p = 0.007) and shape (p = 0.007). Sensitivity and specificity of CTC for the identification of patients with polyps > or = 10 mm were 88% and 100%, respectively.
Conclusions: CTC is a highly accurate technique for the identification of colorectal polyps. Its diagnostic accuracy depends on lesion's size and shape.