CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography

• Published in: European radiology 2003-07, Vol.13 (7), p.1657-1663
• Main Authors: Oto, Aytekin, Gelebek, Veli, Oguz, Berna Sayan, Sivri, Bülent, Deger, Ahmet, Akhan, Okan, Besim, Aytekin
• Format: Article
• Language: English
• Subjects: Colon; Colonic Polyps - diagnostic imaging; Colonography, Computed Tomographic; Colorectal cancer; Colorectal Neoplasms - diagnostic imaging; Contrast Media; Humans
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-002-1770-y

The aim of this study was to calculate pre- and postcontrast CT attenuation values of benign colorectal polyp and carcinoma lesions detected by virtual colonoscopy, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid in the colon. Fifteen benign polyps and 21 colorectal carcinoma lesions detected by virtual colonoscopy in 18 patients were included in our study. All of the polyps and carcinoma lesions were confirmed by colonoscopic biopsy. Measurement of CT attenuation values was performed in precontrast (supine) and postcontrast (prone) scans for each polyp and carcinoma. The CT attenuation values of residual fluid in the colon was also measured from the same location before and after intravenous contrast administration. On unenhanced CT scan mean attenuation values of benign polyps and colorectal carcinomas were 32.4 and 42.6 HU, respectively. Following contrast enhancement, mean attenuation value increased to 78.9 HU for polyps and 90.7 HU for carcinomas. Increase in the CT attenuation values of these lesions was significant ( p