Computed tomography colonography in routine clinical practice

To describe the experience of a radiology unit in using open access computed tomography (CT) colonography instead of double-contrast barium enema in patients who refused or had an incomplete first-attempt colonoscopy.

All consecutive patients who underwent CT colonography from December 1998 to August 2001 were recalled and evaluated. Patients in whom CT colonography showed intraluminal growths were sent for colonoscopy, performed using deep sedation if the first attempt failed.

A total of 463 consecutive CT colonography examinations were performed: 304 patients were re-traceable and were evaluated. In 85 cases CT colonography reported the presence of intraluminal growth. Colonoscopy confirmed the presence of 74 of the 94 polyps, and of 43 of the 48 cancers found at CT colonography. Colonoscopy also diagnosed an additional two cancers in two patients with CT colonography findings of inflammatory changes, and an additional 26 polyps in 16 patients. On a per-lesion basis, the positive predictive value of CT colonography was 73%, 80% and 87% for polyps /= 10 mm, respectively, and was 90% for cancer. On a per-patient basis, the positive predictive value was 60%, 72% and 89% for lesions /= 10 mm, respectively, and was 93% for cancer.

CT colonography on an open access basis can be confidently used as a routine test instead of double-contrast barium enema when total colonoscopy cannot be performed.