Simultaneous liver T1, T2, and ADC MR fingerprinting using optimized motion-compensated diffusion preparations: An initial validation on volunteers.

Abstract

Purpose: To develop a novel MR fingerprinting sequence using optimized motion-compensated diffusion preparations for simultaneous T₁, T₂, and ADC quantification of liver tissue in a single breath-held scan.

Methods: A radial spoiled gradient echo acquisition with magnetization preparation modules for T₁, T_2, and ADC encoding is proposed. To compensate for the signal voids generated by the diffusion preparation, the combination of (1) a breath-held scan, (2) peripheral pulse signal triggering, and (3) an optimized motion-compensated diffusion-preparation module is employed. Phantom experiments were performed to test the accuracy of the technique. The sequence was evaluated in 11 healthy subjects in comparison to conventional mapping techniques. Additional in vivo repeatability assessment experiments were performed.

Results: T₁, T₂, and ADC quantification showed good correlation (r² > 0.9 for all cases) with reference maps in phantoms and good agreement in vivo against clinical scans (bias not significantly different from zero). A peripheral pulse trigger delay of 200 ms was used to reduce cardiovascular motion artifacts. The repeatability tests prove a low interscan coefficient of variation and a high intraclass correlation coefficient of greater than 0.9 for all cases.

Conclusions: Simultaneous quantification of T₁, T₂, and ADC in liver tissue in a single MR fingerprinting scan of ˜16 s has been proposed, enabling a comprehensive evaluation of hepatic disease through co-registered multiparametric imaging. Further studies are warranted to test this approach in patients with suspected diffuse liver disease to evaluate its potential for liver tissue characterization and tumor staging.