Quantitative computed tomographic evaluation of bone mineral density inbeagle dogs: comparison with dual-energy x-ray absorptiometry as a goldstandard

[摘要] This study aimed to demonstrate the higher accuracy and reproducibility of quantitativecomputed tomography (QCT) compared with dual-energy X-ray absorptiometry (DXA) as a goldstandard for measuring canine bone mineral density (BMD). Seven middle-aged beagle dogsunderwent lumbar vertebral and bilateral femoral DXA and QCT scans. BMD(mg/cm2) was measured at the vertebral body from L2 to L6, femoral neck, andproximal and distal femoral diaphyses. The BMD values were measured 3 times and compared.The BMD value on QCT was higher than that on DXA for femoral BMD but not for vertebralBMD. The correlation was strong for the lumbar vertebrae (r=0.66) and was strongest for L3(r=0.85). No correlation was found for the femoral neck (P=0.35), andonly moderate correlations were found for the proximal and distal femoral diaphyses(r=0.43 and r=0.40, respectively). The limits of agreement were narrower for vertebral BMDthan for femoral BMD, and L3 had the narrowest limits of agreement. The intraclasscorrelation (ICC) was higher for DXA than for QCT at all lumbar and femoral sitesmeasured, but the ICC of QCT was higher than 0.7. In conclusion, L3 can be used to monitorchanges in BMD, and relative values and sequential monitoring of femoral BMD can also beuseful because of the high reproducibility of QCT measurements. QCT would be a usefultechnique for evaluation of BMD in veterinary practice.

[学科分类] 兽医学

[关键词] bone mineral density (BMD);dog;dual-energy X-ray absorptiometry (DXA);quantitative computed tomography (QCT)