EVALUATION OF BONE-MARROW IRON BY MAGNETIC-RESONANCE-IMAGING

Bone marrow iron was estimated by magnetic resonance imaging (MRI) usi ng spin-echo sequences with multiple echoes in 22 patients with varyin g degrees of tissue storage iron. Levels of bone marrow iron concentra tion (BMIC) were determined chemically in biopsied specimens concurren tly. Concentrations of serum iron, serum ferritin, and transferrin sat uration were also measured to evaluate body iron status. Significant c orrelation was observed between BMIC and T-2 relaxation rate (1/T-2) ( r = 0.77; p < 0.001) in all patients with BMIC levels below 400 mu g/m l, while BMIC was not correlated with T-2 in patients with extremely h igh BMIC levels. MRI was considered to be inappropriate for quantitati on of 1/T-2 in patients with extremely high BMIC due to an extreme sho rtening of T-2 relaxation time. These observations suggest that MRI ma y be a useful and noninvasive method for systemic quantitative determi nation of bone marrow iron.