Use of Endoluminal and Transabdominal Ultrasound Biomicroscopy to Measure Colon Wall Thickness in Healthy and Tumor-Bearing Mice

Colorectal cancer (CRC) ranks among the most prevalent tumors, particularly affecting men and women, with mouse models and imaging technologies like colonoscopy, endoluminal (eUBM), and transabdominal (tUBM) ultrasound biomicroscopy playing pivotal roles in exploring new treatment avenues. The evaluation of colon wall thickness (Wt), a significant marker of tumor presence, is feasible through eUBM or tUBM, contrasting with colonoscopy's limitations. This study scrutinizes the consistency of Wt measurements obtained via eUBM and tUBM in mice, with or without colon tumors induced by azoxymethane (AOM) and dextran sulfate sodium salt (DSS). UBM images were captured using both eUBM and tUBM instruments, with subsequent Wt measurements performed using ImageJ software. Comparison between Wt obtained from eUBM and tUBM images used the One-Way ANOVA, for normal distributed data, or the Kruskal-Wallis test otherwise. Local Ethics Committee for Animal Use in Research approved the work (protocol 014/20). In general, the results indicate a substantial median Wt disparity between control and tumor groups measured by both techniques (p<0.05). Notably, discrepancies in Wt findings between the two methods were observed in the control group (p<0.05), despite the excellent resolution of the images in delineating colon layers.