S Picchietti

CT colonography : contrast enhancement of benign and malignant colorectal lesions versus fecal residuals

We retrospectively reviewed the computed tomographic colonographic datasets of 22 patients. Mean attenuation values of benign polyps before and after contrast administration were 30u2009±u200915 HU and 90u2009±u200918 HU, respectively. Mean attenuation values of colorectal cancer before and after contrast administration were 43u2009±u200915 HU and 124u2009±u200918 HU, respectively. The mean attenuation value of solid fecal residuals was 43u2009±u200915 HU. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant (mean 60 HU, p < 0.01); the same was true for colorectal cancer (mean 81 HU, p < 0.01). The difference between postcontrast density of polyps and cancer with respect to density of solid fecal residuals was statistically significant (p < 0.01). The use of contrast medium could be of help in computed tomographic colonography for discriminating polypoid benign lesions and colorectal cancer from fecal residuals.