T2-shortening effect of gadolinium with optimal condition to increase CNR for the evaluation of biliary system : phantom study

Abstract

[한글]

[영문]PURPOSE: In evaluating neonatal cholestasis, depiction of common bile duct is important to exclude biliary atresia in which early operation is needed. During MRCP, T2-shortening effect of gadolinium can increase contrast-to-noise ratio (CNR) of bile duct and enhance the depiction of it. The purpose of this study is to confirm the T2-shortening effect of gadolinium, to evaluate the effect of different gadolinium chelate with different gadolinium concentrations and different magnetic field strength to suggest the optimal combination of these conditions, and to find the maximum CNR for the evaluation of biliary system using a phantom study.MATERIALS AND METHODS: MR imaging of T2-weighted single-shot fast spin echo sequence and T2 relaxometry were performed with a sponge phantom and a syringe tube. Two contrasts (Gd-DTPA and Gd-EOB-DTPA) with different gadolinium concentrations were evaluated in 1.5T and 3T. Signal intensities, CNRs, and T2 relaxation time were analyzed.RESULTS: Signal intensities decreased significantly as gadolinium concentrations increased (p<0.001) with both contrasts. And these were higher on 3T (p<0.001). CNRs were higher on 1.5T (p<0.001) and showed no significant change with different gadolinium concentrations. T2 relaxation time also showed a negative correlation with gadolinium concentrations (p<0.001) and decreased more with Gd-EOB-DTPA (than Gd-DTPA; p<0.001) on 3T (than 1.5T; p<0.001).CONCLUSION: There is a T2-shortening effect of gadolinium which shows a negative correlation with gadolinium concentration in both signal intensities and T2 relaxation time. Higher CNR could be obtained with Gd-DTPA on 1.5T.