Clinical Value Of Quantitative CT Without External Phantom In Bone Mineral Density Measurement

Objective:To analyze the correlation between quantitative CT(QCT)without external phantom and dual energy X-ray(DXA)in bone mineral density measurement results and to compare osteoporosis diagnosis of the two measurement methods,to discuss the clinical application value of QCT without external phantom.Methods:A retrospective analysis was performed on 87 cases admitted to orthopedic department of shengjing hospital of China Medical University from November 2016to April 2018,including 31 males and 56 females aged 35-85(60.22±10.31)years old with body mass index 18.67-31.23(24.46±3.05)kg/m~2.Lumbar vertebrae L1-L4 of 87cases were detected by HOLOGIC dual energy X-ray and QCT without external phantom respectively,DXA and QCT without external phantom values of each vertebrae of L1-L4,total bone density,T values of DXA and QCT were recorded respectively.Results:There was a significant correlation between DXA and QCT without external phantom.The correlation coefficients of DXA and QCT without external phantom of L1 to L4 were 0.720,0.728,0.723 and 0.695 respectively,correlation coefficients of DXA and QCT without external phantom for total bone density,T-value were 0.695and 0.711 respectively,P values were 0.000<0.05,21 cases(24.1%)were diagnosed by DXA,31 cases(35.6%)were diagnosed with osteoporosis by QCT without external phantom.12 cases(13.8%)were diagnosed with osteoporosis by QCT without external phantom not DXA,and 2 cases(2.3%)were diagnosed with osteoporosis by DXA not QCT without external phantom.It was calculated that?~2=12.788,P=0.005<0.05 by McNemar-Bowker,which was statistically significant.There were differences between DXA and QCT without external phantom in diagnosis of osteoporosis,QCT without external phantom had a higher detection rate of osteoporosis.Taking DXA as the gold standard for the diagnosis of osteoporosis,the coincidence rate of QCT in normal bone density was 88.9%,the coincidence rate in osteopenia was 65.5%,and the coincidence rate in osteoporosis was 61.3%.The more severe osteoporosis was,the greater the error in DXA.Conclusion:QCT without external phantom is more accurate and sensitive compared with DXA,which can be used as another reliable method to measure bone density besides DXA.QCT without external phantom should play a significant role in diagnosis of osteoporosis in clinic.