Volume rendering with color coding of tagged stool during endoluminal fly-through CT colonography: effect on reading efficiency.

Abstract

Institutional review board approval and informed consent were obtained. This study was conducted to evaluate a newly developed technique for discriminative color coding of tagged stool during three-dimensional (3D) endoluminal fly-through computed tomographic (CT) colonography and to determine its effect on reading efficiency. Thirty patients, including three dropouts, were prepared with moderate cathartic preparation (20 mg bisacodyl, three doses of 200 mL of 5% wt/vol barium sulfate). Images were reviewed by two independent readers with and without color coding. Reader preference, interpretation time, and diagnostic performance were evaluated. Both reviewers preferred color coding. With color coding, interpretation time was shortened by 3 minutes (reader 1, P = .002) and 2.5 minutes (reader 2, P = .009); sensitivity for 6-mm-diameter or larger lesions remained constant at 96% (24 of 25; 95% confidence interval: 78.9%, <100%; P = >.99). This technique facilitates primary 3D interpretation of images obtained with moderate cathartic preparation.