Purpose: To assess the marrow lipid water ratio (LWR) and spectral line width (LW) of lumbar vertebra by proton MR spectroscopy ((1)H MRS) and correlate with the marrow blood perfusion (MBP) by contrast-enhanced dynamic MRI (dMRI) in female subjects.
Materials and methods: A total of 50 female subjects were included. Single-voxel (1)H MRS was measured at the L3 vertebrae. In the dMRI study, the maximum enhancement percentage (E(max)) and enhancement slope were calculated from time-intensity curves. Pearson's correlation was calculated to explore the association of (1)H MRS, age, and perfusion parameters. Partial correlation was then used to control confounder effect.
Results: LWR was negatively correlated with E(max) (r = -0.72; P < 0.0001), but positively correlated with age (r = 0.63; P < 0.0001). Lipid LW was negatively correlated with age (r = -0.33; P <0.05), but positively correlated with E(max) (r = 0.4; P < 0.05). After adjusting for the age effect by partial correlation, marrow LWR still negatively correlated with E(max) (r = -0.63; P < 0.0001). After adjusting for the E(max) effect, marrow LWR still positively correlated with age (r = 0.37; P < 0.05).
Conclusion: After controlling the age factor, the LWR and water LW has significant negative correlation with vertebral BMP. Further investigation is needed to explore the relationship between bone marrow fat metabolism and angiogenesis.
(c) 2006 Wiley-Liss, Inc.