Clinical Usefulness of 3D-CT for Colorectal Cancer

Abstract

We have conducted research on three-dimentional (3D) -CT image, especially CT enema (air-contrast enema) with multidetector-row CT (MDCT) , whether CT enema is useful as preoperative examination of colorectal cancer.
The purpose of this study was to evaluate cancer location and depth of invasion using CT enema images obtained by MDCT. Eighty-seven patients (96 lesions) with pathologically proven colorectal cancer were enrolled. After conventional colonoscopy and gaseous distension of the large intestine, MDCT scans using Aquilion (TOSHIBA, Tokyo, Japan) were performed with intravenous administration of contrast medium. With the data obtained by MDCT, we reconstructed CT enema images and assessed detectability of cancer location and profile images for diagnosis of depth of invasion. The depth of invasion was evaluated by the deformity of the lesion in the colorectal wall. The deformity was classified into five groups : none, wedge shape, semilunal, trapezoid and apple-core like.
The detectability of cancer locations was 94.8% using marking clip that was applied during colonoscopy (91 of the 96cases) .
In conclusion CT enema demonstrated a good detectability of colorectal cancer location. As depth of invasion became deeper, grade of the deformity became more severe. CT enema appears to be an useful preoperative examination for laparoscopic and open surgery. Since 3D-CT is less invasive examination compared to barium-contrast enema, it might be a preferred method for preoperative examination of colorectal cancer.