ESTIMATION OF SPINAL BONE-DENSITY USING CONVENTIONAL MRI - COMPARISONBETWEEN MRI AND DXA IN 32 SUBJECTS

We evaluated the usefulness of MRIT1 and T2 relaxation times in assess ing bone mineral status. T1 and T2 relaxation times of L3 were measure d in 16 pairs of identical twins (24 men, 8 women), aged 25-69 years. Bone mineral density (BMD), bone mineral content (BMC) and apparent vo lumetric bone mineral density (BMDvol) of L3 were measured from the sa me subjects using dual x-ray absorptiometry (DXA). T2 relaxation time correlated inversely with BMD and BMC (r-0.40 and r-0.47, respectively ), whereas a significant positive correlation between T1 relaxation ti me and BMDvol was found (r 0.36). The measurement of T1 may give some information on bone mineral status in clinical MRI measurements when D XA is not available. It is possible that T1 and T2 reflect not only bo ne density, but also other factors related to bone structure.