Computer aided villi morphometric quantification in video-capsule enteroscopy: A newly developed software to quantify small bowel atrophy.

Background and aims: Small bowel capsule endoscopy (SBCE) has an established role in patients with non-responsive celiac disease (CeD). A non-invasive method to quantify small bowel atrophy is still lacking.

Methods: We analysed SBCE frames from CeD patients from 2018 to 2020. Histology was the reference standard, with atrophy defined as Marsh-Oberhuber score ≥ 3a. Three regions of interest (ROI) were blindly selected from each frame by an expert gastroenterologist and analysed using a National Institute of Health J image-processing software into a numerical scale. A 3D surface plot macro identified intestinal villi density through isolines plots.

Results: We acquired 306 ROIs from 57 frames with macroscopic atrophy and 45 with normal mucosa. Frames were classified as atrophic (n = 63) or non-atrophic (n = 39) per Marsh-Oberhuber classification. Median density score significantly differed between atrophic and non-atrophic frames (p < 0.001). The morphometric analysis showed a sensitivity of 77 % and a specificity of 79 % in discriminating between atrophic or non-atrophic mucosa with a 14.10 cut-off (Youden Index) and an overall AUC of 0.805 (CI 95 % 0.712-0.897).

Conclusions: Our newly developed SBCE software can effectively quantify villous atrophy. Further studies are needed to validate its applicability in an external cohort.