Computed Tomography Colonography: Patient Tolerance to CO2 Insufflation

Abstract

ABSTRACTComputed Tomography (CT) colonography, also known as “virtual colonoscopy” is a relatively new technique for colorectal evaluation. It allows imaging of the colonic mucosa and wall similar to those obtained during conventional colonoscopy. The aim of the present study was to investigate patient tolerance to carbon dioxide (CO2) insufflation during CT colonography and whether the CO2 insufflation was adequate to distend the bowel sufficiently for radiological diagnosis. This study also aimed to demonstrate a relationship between patient age and patient tolerance to CO2 insufflation. This research investigated 22 patients (50 per cent male, mean age 64 years) with a variety of clinical indications. CO2 was insufflated through a rectal catheter to the maximum extent of patient tolerance. Volumetric data of the abdomen and pelvis was acquired in a single breathold using a GE Lightspeed Plus multislice CT scanner with the patient in the supine and prone positions. The CO2 insufflation time for the supine and prone series was recorded and the patients rated their tolerance to the CO2 insufflation based on a modified Likert scale. The results were analysed using scatter graphs and Pearson's Correlation Coefficient, mapping the CO2 insufflation time for the prone and supine series and comparing it to patient age. The findings indicate that there was a statistical significance between patient age and patient tolerance (r=−0.47), however, no statistical significance was found between the other variables. This may be due to several reasons including variable bowel length and a small sample. Additional studies are required with a larger sample in order to further investigate this topic.