Quantifying Liver Fat Using a Low-Field Unilateral MR System

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent condition with a large impact on public health, but remains largely undetected among individual patients. MRI proton density fraction (MRI-PDFF) is the gold standard method for measuring liver fat content, but might be regarded as “overkill” for this diffuse liver disease process. There is a pressing current medical need for simpler non-invasive approaches to measure and track liver fat content over time, for which emerging unilateral permanent magnet MR technology is uniquely suited. In this study, we evaluate the potential of the barrel magnet system first described by Utsuzawa and Fukushima in 2017 to quantify liver fat content. We tested this novel unilateral MR system in oil–water emulsions and subsequently with ex vivo tissue samples from normal and fatty duck livers. In oil–water emulsions, the system provided good linear agreement between fat signal amplitudes derived from Bayesian analysis of MR signals and known oil content. Clear differences in water and fat signal amplitudes were also observed between normal and fatty liver samples. The ability to discriminate differences in fat content as little as 5% demonstrates clear potential clinical relevance for medical management of NAFLD using a scaled-up system designed for human studies.