Manual Carbon Dioxide Insufflation for CT Colonography: Effectiveness of Colonic Distention Using Manometer

Abstract

Objective: The purpose of this study was to determine the effectiveness of manual carbon dioxide insufflation using a manometer in colonic distention for CT colonography.
Methods: One hundred forty asymptomatic subjects underwent CT colonography using either manual carbon dioxide insufflation with (study group, n=70) or without (control group, n=70) a manometer. CT data sets were assessed by two blinded observers who graded distention for six colonic segments using a 4-point scale. The insufflated gas volume for all subjects and the rectal pressure for the study group were recorded before scanning acquisitions.
Results: The insufflated gas volume used in the study group was greater than that in the control group. The mean distention scores for the study group were 3.64 and 3.78 in the initial and second scanning positions, respectively, versus 3.62 and 3.47 for the control group, respectively. Although overall colonic distention in the initial position did not differ between groups (p=0.578), the study group showed significantly improved distention in the second position compared to the control group (p<0.0001). The mean rectal pressures were 32.6mmHg and 31.2mmHg for the initial and second scanning positions, respectively.
Conclusion: Manual carbon dioxide insufflation using a manometer significantly improved colonic distention compared to insufflation without a manometer.