Quantitative assessment of bone marrow cellularity by magnetic resonance imaging in workers with long-term exposure to solvents.

This study was conducted to develop a noninvasive method of bone marrow cellularity evaluation in solvent-exposed painters. Six painters with hypocellular marrow and 132 referents were examined using magnetic resonance imaging (MRI). Full examination of the peripheral blood and bone marrow biopsy was done on each patient. Signal indices were calculated from the signal intensities measured at the vertebral bodies from T12 to S1 and on the paraspinal muscles on both the T1- and the T2-weighted image (T1WI and T2WI). Bone marrow cellularities of the painters were between 20.3% and 33.6%. Signal indices at T1WI were greater in the hypocellular marrow cases compared to those of the referents (p<0.05, p<0.01) and were significantly higher in older women compared with men (p<0.05). After adjusting for age and gender, the signal index of cases at S1 of T1WI was higher than that of the referents by 0.364. Five of the six cases had signal index at S1 of T1WI higher than the mean +1 standard deviation for the same age group and gender. MRI signal indices can be used as a useful indicator of bone marrow cellularity in a high-risk population after adequate adjustment.