Longitudinal changes on liver proton density fat fraction differ between liver segments

BACKGROUND: To study the spatial heterogeneity of liver fat fraction changes during a long-term lifestyle intervention study using magnetic resonance imaging (MRI). METHODS: Thirty-two subjects underwent two MRI-scans in a span of one year. A chemical shift encoding-based water-fat separation method was applied to measure liver proton density fat fraction (PDFF) maps. The PDFF changes in the two liver lobes and the Couinaud segments were compared with the mean liver PDFF change. RESULTS: The slope of the relationship between mean liver PDFF changes and PDFF liver lobe changes was higher in the right compared to the left lobe (slope(mean PDFF whole liver ~ mean PDFF right lobe) =1.08, slope(mean PDFF whole liver ~ mean PDFF left lobe) =0.93, P