Improved hepatic arterial phase MRI with 3-second temporal resolution.

Purpose: To assess 3-s temporal resolution for arterial phase bolus timing on dynamic liver MRI.

Materials And Methods: One hundred consecutive patients undergoing fluoro-triggered dynamic gadoxetate enhanced liver MRI with standard Cartesian k-space LAVA (Liver Acquisition with Volume Acceleration) were compared with 61 consecutive patients imaged using spiral k-space LAVA reconstructed at 3-s temporal resolution with sliding window reconstruction. For qualitative analysis, bolus timing, hepatic artery branch order visualized, and overall image quality were evaluated. For quantitative analysis, contrast to noise ratio between aorta and liver parenchyma, aorta and portal vein, and signal intensity ratio between aorta and liver parenchyma were calculated.

Results: MR fluoroscopy triggered single phase standard LAVA produced optimal arterial phase timing in 35% patients, compared with 88% with Spiral LAVA (P < 0.0001). Spiral LAVA had superior bolus timing scoring 2.0, compared with 1.0 with standard LAVA (P < 0.0001). Overall image quality and hepatic artery branch order visualization scoring were superior on spiral LAVA, compared with standard LAVA (P < 0.001). The aorta to liver parenchyma signal intensity ratio was also superior on spiral LAVA, compared with standard LAVA (2.8 vs. 2.2; P < 0.001).

Conclusion: Dynamic liver MRI bolus timing improves using 3-s temporal resolution.