Basal Indentation Due to a Function of Geometry on CT Air-Contrast Enema for Sessile Colorectal Polyps: Quantitative Evaluation using Cross-Sectional Multiplanar Reconstruction - Abstract
Objective: Basal Indentation (BI) on CT air-contrast enema (CT enema) for colorectal cancer consists essentially of the both factors of a function of geometry and a tumor invasion. This study was conducted to investigate the feasibility of quantitative evaluation of the basal indentation due to a function of geometry (BI-G) on CT enema for colorectal polyps using Cross-Sectional Multiplanar Reconstruction (CS-MPR) images.
Materials and Methods: The study group consisted of 21patients with 37 sessile colorectal polyps that were pathologically confirmed as restricted to the mucosa. We calculated the maximal depth of BI-G (max BI-G) on CT enema for colorectal polyps, and compared the max BI-G with the estimated max BI-G (e-max BI-G), which was calculated using the CS-MPR images.
Results: A strong positive correlation was found between e-max BI-G and max BI-G (R2= 0.91, P <0.0001), although there was a significant difference in the mean values between e-max BI-G and max BI-G (0.64 ± 0.52 mm and 0.51 ± 0.73 mm, respectively; P < 0.05).
Conclusion: CS-MPR is effective for quantitative evaluation of BI-G on CT enema for sessile colorectal polyps. Such evaluation may lead to improvement of the diagnostic accuracy of the invasion depth of colorectal cancers.