The aim of the study was to determine whether serum iron and ferritin levels are determinants of iron accumulation in bone marrow using a three-dimension Fat Analysis & Calculation Technique (FACT) sequence.
We measured spinal marrow R2* using a 3T FACT sequence in 112 postmenopausal women (mean age, 62.6 years; range, 50–82.6 years). Serum iron and ferritin levels were determined in blood specimens. Lumbar spine bone mineral density was measured by dual-energy x-ray absorptiometry. The levels of serum iron and ferritin were evaluated in relation to the spinal marrow R2* values before and after adjustments for potential confounders.
In the unadjusted model, magnetic resonance imaging–based spinal marrow R2* was positively correlated to the levels of serum ferritin (Spearman ρ = 0.436, P < 0.001) and iron (Spearman ρ = 0.245, P = 0.009). Multiple stepwise linear regression analyses (adjusting for age, years since menopause, body mass index, alcohol intake, tobacco use, physical activity, serum lipids profile, biomarkers of bone turnover, and lumbar spine bone density) were performed in 3 separate models with marrow R2* values as potential explanatory variables. The level of serum ferritin, but not iron, was an independent predictor of marrow R2* (standardized β coefficient, 0.302, 95% confidence interval, 0.141–0.509, P = 0.001). Similarly, spinal marrow R2* increased with a linear trend from the lowest (<139 ng/mL) to highest (≥180 ng/mL) serum ferritin quartiles (P for trend = 0.007).
Quantitative assessment of R2* derived from FACT is a fast, simple, noninvasive, and nonionizing method to evaluate marrow iron accumulation.