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

Abstract

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). Sigmoid apex height relative to the lumbosacral junction was also measured. Datasets were quantified twice each, and intra-reader reliability was evaluated using concordance correlation coefficient and Bland-Altman plot. Complete quantitative datasets including the five proposed metrics were generated from 58 of 60 (97 %) CTC examinations. The sigmoid and transverse segments were the longest (55.9 and 51.4 cm), had the largest volumes (0.410 and 0.609 L), and were the most tortuous (3.39 and 2.75 high curvature points) and least compact (3347 and 3595 mm), noting high inter-patient variability for all metrics. Mean height of the sigmoid apex was 6.7 cm, also with high inter-patient variability (SD 6.8 cm). Intra-reader reliability was high for total and segmental lengths and sigmoid apex height (CCC = 0.9991) with excellent repeatability coefficient (CR = 3.0-3.3). There was low percent variance of metrics dependent upon length (median 5 %). Detailed automated quantitative assessment of colonic morphology on routine CTC datasets is feasible and reproducible, requiring minimal reader interaction.

An Intestinal Centerline Extraction Algorithm Based on Federated Framework

“…The segmentation effects of different algorithms are shown in Table 2. The double-threshold method [29] manually sets two thresholds to deal with the influence of volume effect and realize intestinal segmentation. The effect of this method has a great relationship with the selection of threshold and does not consider the difference of internal data in the same group, so the effect is not good.…”

Domain-Based Analysis of Colon Polyp in CT Colonography Using Image-Processing Techniques

“…Smaller polyps (size < 5mm) were underestimated by CTC in a study and the sensitivity for measuring these is too low and there are differences of opinion about their clinical significance (Song et al, 2014). The complexity involved in measurement of a smaller polyp is due to its irregular geometrical shape (Lefere and Gryspeerdt, 2011;Weber et al, 2017). Pareto front approach uses Curvature-based region growing technique.…”