Linear Polyp Measurement at CT Colonography: In Vitro and in Vivo Comparison of Two-dimensional and Three-dimensional Displays

PURPOSE: To compare the accuracy of polyp measurement at computed tomographic (CT) colonography by using two-dimensional (2D) multiplanar reformation (MPR) and three-dimensional (3D) endoluminal displays obtained both in a colon phantom and at clinical examinations. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval, and all patients provided signed informed consent, both of which allowed for additional retrospective evaluation. Two-dimensional and 3D CT colonography displays were generated from data obtained in an in vitro colon phantom that contained 10 6–13-mm synthetic polyps and from data obtained at in vivo clinical CT colonography examinations performed in 10 patients (five men, five women; mean age, 56.3 years) with proved polyps (size range, 7–25 mm). The reference standard for in vivo polyp size was optical colonoscopic measurement with a calibrated linear probe. Polyps were measured at CT colonography with 2D MPR and 3D endoluminal displays and electronic ...