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Updated: Jun 30, 2026

A 3D Quantification Technique for Liver Fat Fraction Distribution Analysis Using Dixon Magnetic Resonance Imaging
Published on: October 20, 2023
Exploring the mediating role of bone marrow fat in the liver iron-bone density relationship: A quantitative magnetic
Feng Lu1,2, YanJun Zhao1, Zhongjuan Wang1
1Department of Radiology, Jiangnan University Medical Center, Jiangsu, China.
Objectives:
To explore whether bone marrow proton density fat fraction (PDFF) mediates the relationship between liver iron concentration (LIC), assessed via magnetic resonance imaging (MRI)-derived R2∗, and lumbar spine (LS) bone mineral density (BMD) in women.
Methods:
This prospective study included 103 female volunteers (median age 50 years, range 20-80) recruited between June 2019 and January 2021. All participants underwent 3.0T MRI (liver R2∗ mapping and lumbar VIBE-Dixon sequences) and dual-energy X-ray absorptiometry (DXA) on the same day. Mediation analysis was performed using the PROCESS macro, with age as covariate.
Results:
Among the 103 participants (median age 50 years, IQR 38-60; 44% with elevated liver R2∗ > 67.7 s-1), liver R2∗ was positively associated with bone marrow PDFF (β = 0.36, P < 0.001) and negatively associated with LS BMD (β = -0.273, P = 0.004). Bone marrow PDFF showed a negative association with LS BMD (β = -0.286, P = 0.006). Mediation analysis revealed that bone marrow PDFF significantly mediated 37.6% of the liver R2∗-BMD relationship (indirect effect = -0.103; 95% CI: 0.210 to -0.028). Subgroup analyses revealed that these associations were statistically significant only in participants aged ≥ 50 years.
Conclusions:
Bone marrow PDFF partially mediates the inverse relationship between liver iron and BMD in women, particularly in those aged ≥ 50 years, suggesting a potential link between iron metabolism and bone loss that warrants further investigation. Combined MRI assessment of liver R2∗ and bone marrow PDFF may enhance osteoporosis risk stratification.

