Can MR fluoroscopic triggering technique and slow rate injection provide appropriate arterial phase images with reducing artifacts on gadoxetic acid-DTPA (Gd-EOB-DTPA)-enhanced hepatic MR imaging?

PURPOSE: To evaluate whether using MR fluoroscopic triggering technique and slow rate injection improves the quality of arterial phase images in gadoxetic acid-DTPA-enhanced (Gd-EOB-DTPA) MR imaging because of proper acquisition timing and reduction of artifacts. MATERIALS AND METHODS: Two hundred sixteen patients undergoing examination for liver diseases were retrospectively reviewed. All MR images were obtained with two Gd-EOB-DTPA injection protocols: (i) a combination protocol, in which the MR fluoroscopic triggering technique and slow rate injection (1 mL/s) were used; and for comparison, (ii) a conventional protocol, in which adjusted fixed scan delay and ordinary rate injection (2 mL/s) were adopted. Signal-to-noise ratio (SNR) of aorta, portal vein, and liver parenchyma on arterial phase images were calculated. Two blinded readers independently evaluated the obtained arterial phase images in terms of acquisition timing and degree of artifacts. RESULTS: The SNRs of aorta and portal vein on arterial phase images were significantly higher in the combination protocol group (aorta/portal: 221.9 +/- 91.9/197.1 +/- 89.8) than that in the conventional protocol group (aorta/portal: 169.8 +/- 97.4/92.7 +/- 48.5) (P < 0.05). The acquisition timing for arterial phase images with the combination protocol was significantly better than that with the conventional protocol (P < 0.01). The image quality of the combination protocol was significantly higher than that of the conventional protocol (P < 0.01). The occurrence rate of moderate or severe degree of artifacts in the conventional protocol (38.0\%) was more prominent than that in the combination protocol (18.5\%). CONCLUSION: The combination of the MR fluoroscopic triggering technique and slow rate injection provides proper arterial phase images and reduces the artifacts in Gd-EOB-DTPA MR imaging.