Feasibility and optimal timing of T2-weighted imaging after the administration of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid in hepatobiliary MRI

Purpose: Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA: EOB) is a new liver-specific magnetic resonance imaging (MRI) contrast agent. It is usually administered 20 minutes before hepatobiliary-phase MRI. However, this entails that the total examination time is longer. The purpose of this study was to evaluate the optimal time to acquire T2-weighted images (T2WI) after EOB administration in order to reduce the total examination time, and to assess the earliest time after EOB administration that these images can be acquired. Materials and methods: A total of 76 patients were involved in the study and underwent MRI scans. T2WI were obtained at 0, 5, 10, 15, and 20 minutes after administration and the grade of visualization of the liver parenchyma and the biliary tract was evaluated using the following 3-point scale: Grade 0, no change of intensity; Grade 1, slight change; and Grade 2, marked change. Results: Changes in the intensity of the liver parenchyma were noted as Grade 0 or 1, at 5, 10, 15 and 20 minutes after administration in over 90% of patients. On the other hand, changes in the intensity of the biliary tract was noted as Grade 0 at 5 minutes in all patients; however, this tended to change with time, and Grade 2 was noted at 20 minutes in 33% of patients. Conclusion: There is no significant change in the signal intensity of T2-weighted images at 5 minutes after EOB administration. Therefore, we propose that T2-weighted imaging can be performed 5 minutes after EOB administration in order to reduce the total examination time.