Benjamin M. Yeh MD, Presenter: Nothing to Disclose

Bonnie N. Joe MD, PhD, Abstract Co-Author: Nothing to Disclose

John P. Roberts MD, Abstract Co-Author: Nothing to Disclose

Antonio Westphalen MD, Abstract Co-Author: Nothing to Disclose

Chris Freise MD, Abstract Co-Author: Nothing to Disclose

Fergus Vincent Coakley MD, Abstract Co-Author: Nothing to Disclose

To investigate the effect of decreased kVp and increased mA on bile duct branch visualization and radiation dose at CT cholangiography in living potential liver donors.

Informed consent was obtained from 26 living potential liver donors (16 women and 15 men, mean age 36 years, range, 21-53). After receiving 10.3 mg intravenous iodipamide meglumine, all patients underwent CT cholangiography at 80 kVp and 400 mA and again at 120 kVp and 200 mA. Scans were performed sequentially and in random order. The radiation dose-length product was recorded. The CT attenuation of the second order bile duct branches and of the liver parenchyma was recorded. Visualization of the common, first, second, and third order bile duct branches was subjectively rated on a 3 point scale from 0 = not seen to 3 = well visualized. Second order biliary anatomy at CT was recorded for each patient (n=26) and correlated to surgical findings (n = 7).

The mean CT attenuation of the right second order bile ducts was significantly higher at 80 kVp than at 120 kVp (461 versus 298 HU, p 0.05 for all) and the biliary anatomy as determined by CT cholangiography was concordant between 80 and 120 kVp for all 26 patients. Of the 7 patients who donated livers, biliary anatomy as determined by CT cholangiography was concordant with surgical findings in 6 patients. In 1 patient, variant biliary anatomy was missed at both 120 and 80 kVp. The radiation dose at 80 kVp (radiation dose-length product 228 mGy-cm) was 32% lower than that at 120 kVp (334 mGy-cm).

CT cholangiography can be performed with a lower radiation dose using a low kVp high mA technique without compromising image quality in terms of bile duct visualization or biliary branch anatomy.

Yeh, B, Joe, B, Roberts, J, Westphalen, A, Freise, C, Coakley, F, Does Lowering the kVp Improve Duct Visualization or Reduce Radiation Dose at CT Cholangiography for Liver Donors?.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4418273.html