ABSTRACT Purpose To evaluate the influence of driver power and slice thickness on magnetic resonance elastography (MRE)‐derived liver stiffness in human subjects and a tissue‐mimicking phantom. Methods A prospective single‐center observational study was performed involving 34 adult participants (20 males; median age: 29.0 ± 29.3 years) and a standard phantom. MRE was conducted on a 1.5T scanner using a 2D gradient‐recalled echo‐based sequence. Human data were acquired at driver powers of 25%–100% and slice thicknesses of 5 and 10 mm. The phantom was scanned with driver powers of 10%–100% and slice thicknesses from 2 to 10 mm. Two region‐of‐interest (ROI) approaches were applied: (A) fixed‐location ROIs and (B) largest measurable ROIs. Stiffness maps were generated using the MMDI inversion algorithm. Statistical analysis included repeated measures ANOVA, paired t‐tests or Wilcoxon signed‐rank tests, and intraclass correlation coefficients (ICCs). Results Measured whole‐liver stiffness varied modestly over the driver power range, with the effect reaching statistical significance in Method B analysis ( p = 0.037). Measurements of individual slices varied more significantly with driver power (Method A: p = 0.031; Method B: p < 0.001). Slice thickness had a significant effect on individual slice measurements (Method B: p = 0.007) but not on whole‐liver measurements. In phantom studies, both parameters significantly influenced stiffness ( p < 0.001 to p = 0.017). ICCs indicated good to excellent repeatability in vivo (0.79–0.96) and moderate to good repeatability in the phantom (0.62–0.89). Conclusion The results demonstrate that measured MRE‐derived liver stiffness can be influenced by driver power and slice thickness, underscoring the need for standardization of these parameters in both clinical practice and research.
Hańczyk et al. (Wed,) studied this question.