Michael Macari MD, Abstract Co-Author: Nothing to Disclose

Bradley Matthew Spieler MD, Presenter: Nothing to Disclose

Myrna Cobos Barco Godoy MD, Abstract Co-Author: Research grant, Bayer AG

Alec Jeffrey Megibow MD, MPH, Abstract Co-Author: Consultant, E-Z-EM, Inc, Westbury, NY Medical Advisory Board, Siemens AG, Malvern, PA

James S. Babb PhD, Abstract Co-Author: Nothing to Disclose

Bernard Assadourian, Abstract Co-Author: Nothing to Disclose

Anno Graser MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

At MDCT pancreatic pathology may be subtle, especially when data are acquired during the portal venous phase of enhancement. Our purpose was to determine if lesion conspicuity is improved at 80 kVp when compared to 120 kVp.

IRB approval was obtained. 200 patients have undergone abdominal CT utilizing a 64 row dual source dual energy (DSDE) MDCT scanner. The DSDE CT data were acquired with tube A operating at 140kVp-80mAs and tube B at 80 kVp-460mAs. All patients underwent abdominal CT 80 seconds after 1.5 ml/kg ml of IV contrast material were injected via a 20 gauge catheter at a rate of 4 ml/second using a power injector. The data were reconstructed as a weighted average data set of the 140 kVp and 80 kVp acquisitions providing similar image quality to a standard acquisition obtained at 120 kVp. The CT data were further post processed to generate pure 80kVp data sets which were generated automatically by the CT technologist. These data sets were transferred to a PACS. The dictated reports of the 200 patients were reviewed demonstrating 15 patients with pancreatic pathology. ROI cursors were placed on the pancreatic pathology and the adjacent normal pancreas on both the pure 80kVp data set and the weighted average data set at the same Z axis position. The mean attenuation of the pathology and pancreas were calculated for each data set. An exact Wilcoxon matched-pairs signed rank test was used to test whether the difference in attenuation between pathology and normal pancreas was higher at 80 kVp than at 120 kVp.

Pancreatic pathology included adenocarcinoma (n=6), focal pancreatitis (n=3), and cystic lesions (n=3), unknown (n=3). The mean ± standard deviation of the difference between the pathologic process in the pancreas and normal pancreas in terms of attenuation was 91.6 ± 32.8 at 80 kVp and 66.6 ± 28.1 at 120 kVp. The Wilcoxon test showed that the mean difference in attenuation was significantly higher at 80 kVp (p=0.0002).

Pure 80 kVp data acquired from a dual source dual energy MDCT scanner demonstrates greater attenuation differences between pancreatic pathology and normal pancreas potentially improving assessment of pathologic processes in the pancreas.

Generation of pure 80 kVp data from DSDE CT may allow improved pancreatic evaluation related to greater attenuation differences between normal pancreas and pathologic processes.

Macari, M, Spieler, B, Godoy, M, Megibow, A, Babb, J, Assadourian, B, Graser, A, et al, , Dual Source Dual Energy MDCT: Comparison of 80 kVp and Weighted Average kVp Data on Pancreatic Lesion Conspicuity.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6009358.html