The role of computed tomographic colonography in patients with incomplete colonoscopy

Objective: This study aims to determine the usefulness of computed tomographic (CT) colonography performed for further examination after incomplete colonoscopy and to emphasize the advantages of this technique. Material and Method: Total of 32 patients (18 female, 14 male) who had incomplete colonoscopy were included in this retrospective study. After bowel preparation of the patient, the images were acquired in supine and prone positions. Primarily, colonic segments were evaluated from rectum to cecum and cecum to rectum for four times via virtual colonoscopic images in supine-prone positions. Then, axial images and coronal-sagittal multiplanar reformatted (MPR) images were evaluated. The patients who underwent incomplete conventional colonoscopy and following CT colonography due to inadequate clearance were excluded from the study. Results: In this study, 3 polyps and 1 lipoma were detected with dimension ≤5 mm while 3 polyps were detected 6-9 mm in dimension whereas 1 polyp and 1 lipoma were determined 10-20 mm in dimension by CT colonography. Tumoral wall thickening surrounding the lumen was encountered in the ascending colon of one patient. According to the CT colonography results, verified with repeated conventional colonoscopy (n=4) or surgery (n=2), in lesions which were <10 mm in diameter carcinoma cells were not detected pathologically while two of the lesions with ≥10 mm in diameter were concordant with adenocarcinoma pathologically. Patients who had obstructive tumor and proximal lesion in CT colonography underwent surgery. Conclusion: CT colonography is an adjunct to conventional colonoscopy in colorectal cancer and polyp investigation.