Abbreviated gadoxetic acid–enhanced mri with second-shot arterial phase imaging for liver metastasis evaluation

Abstract

Purpose: To evaluate the feasibility of an abbreviated gadoxetic acid–enhanced MRI protocol including second-shot arterial phase (SSAP) imaging for liver metastasis evaluation. Materials and Methods: For this retrospective study, a total of 197 patients with cancer (117 men and 80 women; mean age, 62.9 years) were included who underwent gadoxetic acid–enhanced MRI performed by using a modified injection protocol for liver metastasis evaluation from July to August 2017. The modified injection protocol included routine dynamic imaging after a first injection of 6 mL and SSAP imaging after a second injection of 4 mL. Image set 1 was obtained with the full original protocol. Image set 2 consisted of T2-weighted, diffusion-weighted, hepatobiliary phase, and SSAP images (the simulated abbreviated protocol). Acquisition time was measured in each image set. The diagnostic performance of each image set was compared by using a jackknife alternative free-response receiver operating characteristic analysis. Image quality evaluation and visual assessment of vascularity were performed on the original arterial phase images, the SSAP images, and their subtraction images. Results: The acquisition time was significantly shorter in image set 2 than in image set 1 (18.6 vs 6.2 minutes, P < .0001). The reader-averaged figure-of-merit was not significantly different between image sets 1 and 2 (P = .197). The mean motion artifact score was significantly lower for the SSAP images than for the original arterial phase images (P