Correlation Between Vertebral Marrow Fat Fraction Measured Using Dixon Quantitative Chemical Shift MRI and BMD Value on Dual-energy X-ray Absorptiometry

Inyoung Youn, Hwa Yeon Lee, Jae Kyun Kim
2012 Journal of the Korean Society of Magnetic Resonance in Medicine  
Purpose : The purpose of this study was to determine whether there is a significant correlation between vertebral marrow fat fraction measured using Dixon quantitative chemical shift MRI (QCSI) and BMD on dual-energy X-ray absorptiometry (DXA). Materials and Methods: This retrospective study included 68 healthy individuals [mean age, 50.7 years; range, 25-76; male/female (M/F) = 36/32] who underwent DXA of the L-spine and whole body MRI including QCSI of the L-spine and chemical shift MRI of
more » ... cal shift MRI of the liver. The enrolled individuals were divided into subgroups according to sex and T-score [i.e., normal bone density (M/F=27/23) and osteopenia (M/F=9/9)]. Vertebral marrow (Dixon QCSI, TR/TE 10.2/4.8 ms) and hepatic fat fractions (chemical shift technique, TR/TE 110/4.9 and 2.2 ms) were calculated on MRI. We evaluated whether there were significant differences in age, body mass index (BMI), vertebral marrow fat fraction, or hepatic fat fraction among the subgroups. Whether or not the participant had reached menopause was also evaluated in females. The correlations among variables (i.e., age, BMI, vertebral marrow and hepatic fat fractions, BMD) were evaluated using Spearman's correlation method. Results: There were no significant differences in age, BMI, or vertebral marrow and hepatic fat fractions between the two male subgroups (normal bone density vs. osteopenia). In female subjects, mean age in the osteopenic subgroup was greater than that in the normal subgroup (p=0.01). Presence of menopause was more common in the osteopenic subgroup [77.8% (7/9)] than the normal subgroup [26.1% (6/23), p<0.05]. The other variables showed no significant difference between female subgroups. The only significant correlation with marrow fat fraction after partial correlation analysis was that with age in the female subjects (r=0.43, p<0.05). Conclusion: The vertebral marrow fat fraction calculated using the Dixon QCSI does not precisely reflect the mild decrease in BMD for either sex. Index words : Bone mineral density•Bone marrow fat fraction•Hepatic fat fraction, aging Magnetic resonance imaging (MRI) Osteoporosis is the most common metabolic bone disorder, affecting 40% of women and 20% of men older than 50 years (1). Osteoporosis is characterized by reduced bone mass and disruption of bony microstructural integrity, leading to increased fracture susceptibility (2). Therefore, early detection and appropriate intervention for osteopenia and JKSMRM 16(1) :
doi:10.13104/jksmrm.2012.16.1.16 fatcat:ntwp2fawcrgc7bnkkf33a3yhci