Improving Self-Gated Radial MR Elastography for Free-Breathing Quantification of Liver Stiffness in Children

Motivation: MR elastography (MRE) detects liver fibrosis by measuring hepatic stiffness (HS). Breath-holding (BH) is required to avoid motion artifacts, but this is challenging in children. Previous radial free-breathing (FB) MRE eliminated the BH, but required 2 min/slice. Goal(s): To reduce scan time for radial FB-MRE and analyze the effects of self-gating on HS. Approach: Radial FB-MRE was modified to acquire lower resolution and perform spatial interpolation, which reduced the scan time. Self-gating was performed to compensate for breathing motion. Results: In 23 children, self-gated radial FB-MRE (1 min/slice) yielded more accurate and repeatable HS than non-self-gated radial FB-MRE, with respect to standard BH-MRE. Impact: Self-gated free-breathing MR elastography (MRE) of the liver produced accurate and repeatable hepatic stiffness in 1 min/slice, with respect to standard cartesian breath-held MRE, and can be beneficial for children who cannot perform breath-holding.