CT colonography in a rural New Zealand hospital

Computed tomographic colonography (CTC) has been advocated for use after incomplete colonoscopy. Most of the literature is based on data from urban centres. The purpose of this study is to evaluate the use of CTC in a rural New Zealand hospital.

Patient files, electronic endoscopy and radiology records of patients from Timaru Hospital between who had a CTC between 1 April 2004 and 1 December 2006 were retrospectively reviewed.

196 CTCs were performed after incomplete colonoscopy. The diagnostic yield of CTC for lesions > or = 10 mm was 8.7%; and for lesions less < 10 mm was 5.6%. CTC was performed as the primary investigative modality in 568 patients. The sensitivity and specificity of CTC for detecting colonic lesions were 90.7% and 50.4% respectively. The positive and negative predictive values of CTC were 71.9% and 79.5%. The sensitivity and specificity for lesions that were 10 mm or more were 100% and 92.1%.

CTC may be an effective tool for the detection of clinically important colorectal lesions, particularly after incomplete colonoscopy. The advent of remote viewing of radiology images has made it possible to utilise CTC in the rural setting.