In Vitro Measurement of the Bone Mineral Density of the Third Metacarpal Bone by Dual Energy X-Ray Absorptiometry in Racehorses —Comparison with Single Photon Absorptiometry—

摘要

Bone mineral density (BMD, g/cm2) in the distal portion of the third metacarpal bone (McIII) of racehorses was measured by a dual energy x-ray absorptiometry system (DEXA; DCS-3000, ALOKA Co, Ltd., Tokyo, Japan) in vitro, and compared with bone mineral content (BMC, g/cm2) evaluated by a single photon absorptiometry system (SPA: Model 278 A, Norland Co., Fort Atkinson, U.S.A.; radioactive source was 241Am-45mCi). The BMD values measured by DEXA were positively correlated with the BMC values measured by SPA, which has been used to quantitatively assess BMC with high accuracy and reproducibility in racehorses, at 0.01-0.0001 level with a correlative coefficient (r) of 0.625-0.995 (n=30). The reproducibility of values measured by DEXA shows a satisfactory coefficient value (3%), almost same as that (2.7%) of SPA. These results suggest the potential applications of DEXA as a quantifying instrument for the measurement of bone mass of the McIII in racehorses.