Dual-Enerji Bt Kolonografi: Kolorektal Tümörlerin Dual Enerji BT Özellikleri

Abstract

We aimed to define the dual-energy CT characteristics of colorectal cancers and stool. Fifty consecutive patients were included who was referred for staging CT of a colorectal tumor between June 2011 and November 2012. Informed consent were obtained. Dual energy CT was performed by dual-source CT after insufflation of rectal air in supine position. Hounsfield units on 80kV, 140kV and virtual noncontrast images and iodine map were measured. DLP was measured. Statitistical analysis was performed by using Kruskal-Wallis, One-way Anova and Spearman?s rho correlation tests. Mean age of the patients was 60±13 years. Pathologic diagnoses were adenocarcinoma (n=47), squamus carcinoma (n=1), malignant melanoma (n=2). Mean DLP was 511 and estimated dose was 8.2mSv. CT density measurements on iodine map and virtual noncontrast images for tumors and stool were 56H (%95 CI: 61 ? 51H), and 32H (%95 CI: 37 ? 27) and 40H (%95 CI: 48 ? 32H) , -148 H (%95 CI: (-121H) ? (-175H)), respectively. Combination of Iodine map and VNC density values allowed differentiation of tumors from stool in all patients. There was no correlation between dual-energy characteristics and tumor grade, location, thickness and length. Eight polyps were detected on staging CT and density on iodine map and virtual noncontrast images were 70±8H and 16±5H. As an additional finding, liver metastases were found in 6 patients and renal cell cancer was detected in 2 patients. In conclusion, stool and tumors can be differentiated by combination of density measurements from iodine map and virtual noncontrast images. Dual-energy CT may allow diagnosis of coexisting polyps and other abdominal tumors.