Comparison of MR Spectroscopy, 2-Point Dixon, and Multi-Echo T2* Sequences in Assessing Hepatic Fat Fraction Across a Diverse Range of Body Mass Index (BMI) and Waist Circumference Ratio (WCR) Values.

Abstract

Objective: The study aimed to compare and evaluate the accuracy of three magnetic resonance imaging (MRI) sequences-MR liver spectroscopy, 2-point Dixon, and multi-echo T2*-in assessing hepatic fat fraction in patients with various body mass indexes (BMIs).

Methods: 167 participants were recruited, including 110 healthy subjects with diverse BMIs and 57 bariatric surgery candidates. The MRI protocol involved three sequences: multi-echo single voxel STEAM 1H spectroscopy, 2-point mDixon, and multi-echo T2* sequence. Hepatic fat fraction was measured using these sequences and analyzed statistically to determine correlations and agreement between the methods.

Results: A strong positive correlation was observed between BMI and waist circumference ratio (WCR) (r_s(165) = 0.910, p<0.001). MRS obtained hepatic fat fraction numerical values in 13.33% of the normal BMI group, 48.48% of the overweight group, and 72.97% of the obese group. Strong correlations were found between all methods, with significant agreement, particularly between MRS and multi-echo T2*.

Conclusion: Robust correlations were observed between MR spectroscopy, 2-point Dixon, and multi-echo T2* methods for liver fat fraction measurement, especially in patients with higher BMI and WCR. These findings highlight the importance of BMI and WCR in interpreting fat fraction measurements, as method performance can vary across body composition profiles.