Panoramic endoluminal display with minimal image distortion using circumferential radial ray-casting for primary three-dimensional interpretation of CT colonography

The purpose of this study was to develop a panoramic endoluminal display technique, the band view, which causes minimal image distortion, and to determine its feasibility as a time-efficient primary three-dimensional review method of CT colonography (CTC). Image distortion was compared between the band view and four other three-dimensional review modes using ten 10-mm and ten 20-mm electronically generated polyps. Diagnostic performance and interpretation time were compared between the band view and the conventional endoluminal view by two independent readers in 52 patients who underwent CTC and colonoscopy on the same day. Mean image distortion index values, in which 1 indicates no distortion and the larger value represents greater distortion, were significantly smaller with the band view (1.03 and 1.01 for 10-mm and 20-mm polyps, respectively) than with the filet view (1.65 and 1.55) or the virtual colon dissection (3.27 and 3.85) (P≤0.004). The sensitivity and specificity for detecting adenomatous polyps ≥6 mm did not differ, but the mean interpretation time was significantly shorter with the band view than with the conventional endoluminal view by 1.8 and 4.5 minutes in readers 1 and 2, respectively (P<0.0001). The band view can be a time-efficient alternative for primary three-dimensional review of CTC.