Detailed quantitative assessment of colonic morphology at CT colonography using novel software: a feasibility and reproducibility study.

The aim of this study was to evaluate feasibility and reproducibility of quantitative assessment of colonic morphology on CT colonography (CTC). CTC datasets from 60 patients with optimal colonic distension were assessed using prototype software. Metrics potentially associated with poor endoscopic performance were calculated for the total colon and each segment including: length, volume, tortuosity (number of high curvature points <90°), and compactness (volume of box containing centerline divided by centerline length).

Colon unfolding via skeletal subspace deformation.

We present an efficient method to digitally straighten a colon volume using mesh skinning, a technique well known in computer graphics to deform a polygonal mesh attached to a skeleton hierarchy. In our case, the colon centerline is used as the skeleton structure and the polyhedral model of the lumen as the skin that is to be deformed as the centerline is straightened. Once the colon has been straightened, we use standard rendering techniques to compute the virtual dissection.

Computed tomographic colonography: automated tool for polyp measurement delivering on patient risk stratification.

Objective: We evaluated an automated polyp size measurement tool in computed tomographic colonography for its accuracy and value for patient risk stratification.

Methods: A simulation program generated a raw data phantom with sessile and pedunculated polyps of known sizes using 120 to 140 kV and 50, 40, 20, 15, and 10 mAs. All polyps were measured by clicking on the polyp surface.

Comparative performance of two polyp detection systems on CT colonography.

Objective: The purpose of our study was to evaluate two current automatic polyp detection systems to determine their sensitivity and false-positive rate in patients who have undergone CT colonography and subsequent endoscopy.

Materials And Methods: We evaluated two polyp detection systems--Polyp Enhanced Viewing (PEV) and the Summers computer-aided detection (CAD) system (National Institutes of Health [NIH]) using a unique cohort of CT colonography examinations: 31 examinations with true-positive lesions identified by radiologists and 34 examinations with false-positive lesions incorrectly identified by radiologists. All patients had reference-standard colonoscopy within 7 days of CT.

Automated polyp measurement with CT colonography: preliminary observations in a phantom colon model.

Objective: The purpose of this study was to evaluate the accuracy and precision of polyp measurements obtained with an automated tool in a colon phantom containing polyps of multiple sizes, morphologic types, and locations.

Materials And Methods: A colon phantom was scanned at 12, 25, 50, and 100 mA with standard CT colonographic acquisition parameters. Four reviewers using manual 2D methods and an automated polyp measurement tool measured 24 polyps of varying sizes and morphologic types, some at a haustral fold tip and some not at a fold tip.