Linearity and Bias of Proton Density Fat Fraction Across the Full Dynamic Range (0-100%): a Multiplatform, Multivendor Phantom Study at Two Sites.

Motivation: Performance assessment of PDFF in phantoms and in vivo, including linearity and bias, and reproducibility and repeatability, have largely focused between the range of 0-50%. Goal(s): We analyzed PDFF performance in a two-site phantom study across the full 0-100% PDFF range. Approach: We used commercially available quantitative 3D chemical-shift-encoded water-fat MRI pulse sequences across three vendors at 1.5T and 3T. Results: Results demonstrate strong linearity and minimal bias {pooled slope and intercept for 1.5T=0.99 (95% CI: 0.981-0.997), 0.61 (0.17, 1.04); for 3T=1.00 (0.995, 1.005), 0.69 (0.39, 0.97)} of PDFF across 10 MRI systems. Pooled reproducibility coefficient (RDC) across 30 phantom exams was 3.92%. Impact: PDFF across the 0-100% range can be reliably estimated with minimal bias and strong linearity using current commercial offerings from MRI vendors at 1.5T and 3T, with intra-scanner repeatability coefficient<2% (in PDFF%) and inter-scanner, inter-site, and inter-vendor RDC<4% (in PDFF%).