Date Published: April 10, 2019
Publisher: Public Library of Science
Author(s): Velicia Bachtiar, Matthew D. Kelly, Henry R. Wilman, Jaco Jacobs, Rexford Newbould, Catherine J. Kelly, Michael L. Gyngell, Katherine E. Groves, Andy McKay, Amy H. Herlihy, Carolina C. Fernandes, Mark Halberstadt, Marion Maguire, Naomi Jayaratne, Sophia Linden, Stefan Neubauer, Rajarshi Banerjee, Peter Lundberg.
As the burden of liver disease reaches epidemic levels, there is a high unmet medical need to develop robust, accurate and reproducible non-invasive methods to quantify liver tissue characteristics for use in clinical development and ultimately in clinical practice. This prospective cross-sectional study systematically examines the repeatability and reproducibility of iron-corrected T1 (cT1), T2*, and hepatic proton density fat fraction (PDFF) quantification with multiparametric MRI across different field strengths, scanner manufacturers and models. 61 adult participants with mixed liver disease aetiology and those without any history of liver disease underwent multiparametric MRI on combinations of 5 scanner models from two manufacturers (Siemens and Philips) at different field strengths (1.5T and 3T). We report high repeatability and reproducibility across different field strengths, manufacturers, and scanner models in standardized cT1 (repeatability CoV: 1.7%, bias -7.5ms, 95% LoA of -53.6 ms to 38.5 ms; reproducibility CoV 3.3%, bias 6.5 ms, 95% LoA of -76.3 to 89.2 ms) and T2* (repeatability CoV: 5.5%, bias -0.18 ms, 95% LoA -5.41 to 5.05 ms; reproducibility CoV 6.6%, bias -1.7 ms, 95% LoA -6.61 to 3.15 ms) in human measurements. PDFF repeatability (0.8%) and reproducibility (0.75%) coefficients showed high precision of this metric. Similar precision was observed in phantom measurements. Inspection of the ICC model indicated that most of the variance in cT1 could be accounted for by study participants (ICC = 0.91), with minimal contribution from technical differences. We demonstrate that multiparametric MRI is a non-invasive, repeatable and reproducible method for quantifying liver tissue characteristics across manufacturers (Philips and Siemens) and field strengths (1.5T and 3T).
As the burden of non-alcoholic fatty liver disease (NAFLD) reaches epidemic levels in developed countries , , there is a pressing need to develop non-invasive, standardised, and quantitative methods . Liver biopsy has long been the gold standard for staging liver disease, yet it is painful, prone to sampling variability , has poor inter-observer concordance  and carries a risk of complications . Magnetic Resonance Imaging (MRI)-based methods are attractive as they are sensitive to subtle differences in tissue composition, can sample the entire liver, and yield objective quantitative measurements that can contribute to prospective patient management –.
The primary goal of this study was to systematically test the repeatability and reproducibility of multiparametric-MRI derived measurements across scanner field strength, manufacturer and model in human participants and phantoms. We report the overall repeatability and reproducibility of standardised cT1, T2*, and PDFF measurements.
Multiparametric MR-derived metrics, cT1, T2* and PDFF, have good repeatability and reproducibility that can quantify liver tissue characteristics independent of scanner manufacturer (Philips or Siemens) and field strength (1.5T or 3T). Multiparametric MRI is a non-invasive method that does not require additional hardware, and can be completed in less than 15-minutes, which will have important implications for routine monitoring and assessment of the liver in clinical practice. The ability to standardize metrics will be important in the clinical trial settings for evaluating treatment interventions.