Application of High-Speed T1 Sequences for High-Quality Hepatic Arterial Phase Magnetic Resonance Imaging: Intraindividual Comparison of Single and Multiple Arterial Phases

Purpose The aim of this study was to compare intraindividual single and multiple arterial phase acquisitions and evaluate which acquisition method was more advantageous for obtaining high-quality hepatic arterial phase in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). Materials and Methods Sixty-seven patients who underwent gadoxetic acid-enhanced liver MRIs and had all 3 kinds of acquisitions (single, dual, and triple arterial phases) were retrospectively included. For hepatic arterial phase imaging, controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) with or without time-resolved imaging with interleaved stochastic trajectories (TWIST) was used. The adequacy of optimal hepatic arterial timing was assessed and respiratory motion artifacts were rated using a 5-point scale, with the highest score indicating the worst image quality. Optimal timing and respiratory motion artifacts among 3 different acquisitions were compared using Fisher exact test and repeated measures one-way analysis of variance with multiple comparisons. Results Optimal timing of hepatic arterial phase was observed in 89.6% (60/67) of single arterial phase acquisitions and 98.5% (66/67) of both dual and triple arterial phase acquisitions (P = 0.015). Respiratory motion artifact was significantly lower in single and dual arterial acquisitions than in triple arterial acquisition (mean score, 1.70 vs 1.90 vs 2.49; P < 0.001), although there was no significant difference between single and dual arterial acquisitions (P = 0.091). Conclusions A 15-second breath-hold dual arterial phase acquisition during gadoxetic acid-enhanced MRI reliably offers well-timed hepatic arterial phase with less respiratory motion artifact. However, a 13-second breath-hold single arterial phase acquisition was most effective in reducing respiratory motion artifact.