Computed tomographic colonography: colonic and extracolonic findings in an Auckland population

To determine the nature and prevalence of colonic and extracolonic findings in our population.

All patients who underwent computed tomographic colonography (CTC) in the 72-month period from 1 January 2004 to 1 January 2010 were included in the analysis. Demographic data and CTC findings were recorded, according to the CT colonography reporting and data system (CRADS).

There were 2152 consecutive CTC patients; comprising 52.6% female, average age of 60 years; range 19-87. Approximately 84% were symptomatic. CRADS: Colonic findings: 99/2152 patients (4.6%) were C2 category (had 1 or 2 polyps of 6-9 mm). 77/2152 (3.6%) patients were C3 category (>9 mm polyp or >2 polyps of 6-9 mm). 55/2152 (2.5%) were C4 category (possible cancer). This comprises a total potential colonoscopy/surgery referral rate of 10.7%. Extracolonic findings: The majority were normal or clinically unimportant findings. 178/2152 (8.3%) had potentially significant extracolonic findings.

Our CTC population is largely symptomatic, and there is a referral rate from CTC to colonoscopy, surgery or surveillance of 10.7%. This is similar to other NZ data and international studies. The 8.3% rate of potentially significant extracolonic findings is at the lower end of the reported range.