CT colonography, also referred to as virtual colonoscopy, has recently been shown to be an accurate screening tool when the 3D display is used for the initial detection of polyps [1]. Although both 2D and 3D CT image displays are useful for virtual colonoscopy interpretation, most investigators to date have relied primarily on the 2D data set for initial polyp detection [2]. However, results from recent studies using a primary 2D approach in low-prevalence populations have been disappointing [3, 4].
