Dong-Ho Bang MD, Abstract Co-Author: Nothing to Disclose

Kwon-Ha Yoon MD, PhD, Abstract Co-Author: Nothing to Disclose

Moo-Sang Kim, Abstract Co-Author: Nothing to Disclose

A Lan Lim, Abstract Co-Author: Nothing to Disclose

Sang Hyun Park, Abstract Co-Author: Nothing to Disclose

Young Hwan Lee MD, Presenter: Nothing to Disclose

To qualitatively and quantitatively compare VNE data sets derived from DECT with TNE data sets in the same patients and to calculate potential radiation dose reductions.

202patients (106men, 96women, mean;50.9 years) who visited our emergency department, underwent enhanced DECT including non-enhanced imaging. The parameters were 80 and 140 kV, auto mAs (caredose 4D program). Collimation was 14x1.2 mm. Quantitatively, CT numbers were measured in renal parenchyma, liver, aorta, and psoas muscle and fluid collection. Effective radiation doses for DECT and TNE images were calculated and image noise was measured on TNE and VNE images. Qualitatively, Image quality, noise and artifact (1= none, 5 = severe) and acceptability for VNE and TNE images were rated (1= complete replaced, 3= non-acceptable). In addition, significant hemorrahge and calcification including biliary, urinary and appendicolith were compared by means of five-point scales (1=more demonstrated on VNE, 2=similar, 3=less but recognizable, 4=suspicious, 5=invisible on VNE). Differences were tested with a Student t test for paired samples.

No significant finding was detected in 68 patients. 26 patients with appendicitis, 41 patients with hepatobiliary pathology, 9 patients with pancreatic pathology, 12 patients with genitourinary pathology, 28 patients with gastrointestinal pathology, 5 patients with gynecologic pathology and 18 patients with mechanical injury were diagnosed, clinically and radiologically. In quantitative analysis, mean CT numbers on TNE and VNE images were similar. Mean dose reduction by omitting the TNE scan was 30%. Mean image quality and noise were 1.98 and 1.96 and replacement score was 1.25. A total of 9 appendicolithes, 18 urinary stones and 45 hepatobiliary stones were detected on TNE. Mean comparison score for calcification between TNE and VNE were 3.00 for appendicolith, 3.34 for urinary stones and 2.64 for biliary stones. Mean comparison score for hemorrhage between TNE and VNE were 2.00.

Image quality and noise of VNE were not inferior to those of TNE. VNE was similar with TNE in detection of hemorrhage. However, small calcifications were sometimes obscured in VNE. Therefore, tailored application of VNE is needed for evaluation of patient with acute abdomen.

VNE was not inferior to TNE. However, tailored application of VNE is needed for evaluation of patient with acute abdomen.

Bang, D, Yoon, K, Kim, M, Lim, A, Park, S, Lee, Y, Dual Energy CT(DECT) in Patient with Acute Abdomen: Is It Possible for Virtual Nonenhanced CT (VNE) to Replace True Nonenhanced CT (TNE)?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9015017.html