Errors in CT colonography

Abstract

CT colonography (CTC) is a colorectal cancer screening modality which is becoming more widely implemented and has shown polyp detection rates comparable to those of optical colonoscopy. CTC has the potential to improve population screening rates due to its minimal invasiveness, no sedation requirement, potential for reduced cathartic examination, faster patient throughput, and cost-effectiveness. Proper implementation of a CTC screening program requires careful attention to numerous factors, including patient preparation prior to the examination, the technical aspects of image acquisition, and post-processing of the acquired data. A CTC workstation with dedicated software is required with integrated CTC-specific display features. Many workstations include computer-aided detection software which is designed to decrease errors of detection by detecting and displaying polyp-candidates to the reader for evaluation. There are several pitfalls which may result in false-negative and false-positive reader interpretation. We present an overview of the potential errors in CTC and a systematic approach to avoid them.

Spectral Photon-counting CT: Initial Experience with Dual–Contrast Agent K-Edge Colonography

“…The differentiation among small and/or flat polyps, contrast material in the colon, and contrast-enhanced fecal material is a major challenge in laxative-free CT colonography with electronic cleansing. Usually, oral ingestion of a positive contrast agent (eg, iodine) is used to tag the fecal material and the residual fluid in the colon (8,9,20). After CT, a postprocessing algorithm (electronic cleansing) removes the fecal material, which is tagged by iodine, from the CT data set.…”

“…After CT, a postprocessing algorithm (electronic cleansing) removes the fecal material, which is tagged by iodine, from the CT data set. For a reliable electronic cleansing procedure, however, it is essential to remove all the fecal material but to preserve polyps, colonic tissue, or tumors in the CT images (20). Therefore, accurate differentiation between the different materials and tissue is mandatory.…”

Utilidad de la Colonografía-TC o Colonoscopia virtual en la patología colorrectal

“…En la literatura hay consenso a la hora de indicar una preparación con dieta pobre en residuos los días previos a la realización de la prueba, pero no hay consenso en lo que respecta a la utilización de laxantes, como indica Trilisky et al 98 en un trabajo publicado en el 2015.…”