Diagnostic Performance and Patient Acceptance of Reduced-Laxative CT Colonography for the Detection of Polypoid and Non-Polypoid Neoplasms: A Multicenter Prospective Trial

Purpose To evaluate the diagnostic accuracy and patient acceptance of reduced-laxative computed tomographic (CT) colonography without computer-aided detection (CAD) for the detection of colorectal polypoid and non-polypoid neoplasms in a population with a positive recent fecal immunochemical test (FIT). Materials and Methods Institutional review board approval and written informed consent were obtained. This multicenter prospective trial enrolled patients who had positive FIT results. Reduced-laxative CT colonography and colonoscopy were performed on the same day. Patients received 380 mL polyethylene glycol solution, 20 mL iodinated oral contrast agent, and two doses of 20 mg mosapride the day before CT colonography. The main outcome measures were the accuracy of CT colonography for the detection of neoplasms 6 mm or larger in per-patient and per-lesion analyses and a survey of patient perceptions regarding the preparation and examination. The Clopper-Pearson method was used for assessing the 95% confidence intervals of per-patient and per-lesion accuracy. Survey scores were analyzed by using the Wilcoxon and χ² tests. Results Three hundred four patients underwent both CT colonography and colonoscopy. Per-patient sensitivity, specificity, positive predictive value, and negative predictive value of CT colonography for detecting neoplasms 10 mm or larger were 0.91 (40 of 44), 0.99 (255 of 258), 0.93 (40 of 43), and 0.98 (255 of 259), respectively; these values for neoplasms 6 mm or larger were 0.90 (71 of 79), 0.93 (207 of 223), 0.82 (71 of 87), and 0.96 (207 of 215), respectively. Per-lesion sensitivities for detection of polypoid and non-polypoid neoplasms 10 mm or larger were 0.95 (40 of 42) and 0.67 (six of nine), respectively; those for neoplasms 6 mm or larger were 0.90 (104 of 115) and 0.38 (eight of 21), respectively (P < .05 for both). Patient acceptance of preparation and examination with CT colonography was significantly higher than that with colonoscopy, and 62% (176 of 282) of patients would choose CT colonography as the first examination if they have a positive FIT result in the future. Conclusion Reduced-laxative CT colonography without CAD is accurate in the detection of polypoid neoplasms 6 mm or larger but is less accurate in the detection of non-polypoid neoplasms. Reduced-laxative CT colonography has high patient acceptance and is an efficient triage examination for patients with a positive FIT. ^© RSNA, 2016 Online supplemental material is available for this article.