Preliminary Studies Of The Value Of Gemstone Spectral CT In Lumbar Osteoporosis

Objective:Osteoporosis(OP)is a kind of metabolic and systemic disease of the skeletal system,its pathological characteristics are reduced to low bone mass,bone microstructure damage,Increase of bone fragility and bone strength decline,the most serious consequence is the occurrence of osteoporotic fractures(brittle fracture),affecting the quality of life of patients seriously and even endangering life have become a serious challenge of government of China,society and family.The internationally recognized dual energy X-ray absorptiometry(DXA)is the gold standard for the measurement of bone mineral density,in recent years,The material decomposition technique of Gemstone spectral CT can be widely used in measurement of bone mineral density of lumbar spine and animal model,In this study,the density of HAP(fat)of the vertebral body was measured by the material decomposition technique of Gemstone spectral CT,and at the same time,compared with bone mineral density measured by double energy X-ray absorptiometry(DXA),The correlation between the density values of the HAP(fat)measured by CT and the bone mineral density measured by double energy X-ray absorption(DXA)was found.To find the best critical point of GSI in the diagnosis of osteoporosis and the clinical application value in the diagnosis of lumbar osteoporosis.Methods:Using DXA as the gold standard,Twenty-two cases of lumbar vertebral body(L1-L4)(88 vertebral body)in which the patients checked in Oingdao Municipal Hospital were divided into osteoporosis group(T≤-2.5SD)、osteopenia group(-1.0~-2.5SD)、and normal group(≥-1.0 SD),according to the diagnostic criteria of WHO.At the same time,All patients were performed abdominal CT examination with GSI and DXA examination.Meanwhile,we measured HAP(fat)density and Bone mineral density(BMD)of DXA in L1-L4 lumbar spine.Exclusion criteria:Patients with primary tumors,metastatic tumors and tumor like lesions;lumbar hyperplasia and osteophyte formation,ligament calcification or ossification and abdominal aortic calcification;lumbar clear recent trauma、fracture and osteoporotic compression fracture patients.Single factor analysis of variance was used to compare the results of the three sets of measurements;HAP(fat)density and DXA bone mineral density was done by Pearson correlation analysis;ROC curve was drawn to find the best critical point of GSI in the diagnosis of osteoporosis.Results:according to dual energy X-ray absorptiometry WHO diagnosis standard,22 patients with 88 vertebral bodies were divided into 25 of osteoporosis group,44 of osteopenia group,19 of normal bone mass group,osteoporosis group,osteopenia group and normal group vertebral body HAP(fat)density were 97.43±17.48mg/cm~3、127.43±16.24mg/cm~3、153.26±18.40 mg/cm~3;There were significant difference in the HAP(fat)density of lumbar spine among osteoporosis group、osteopenia group and normal group(P<0.001);The HAP(fat)density of lumbar spine was positively related to DXA bone mineral density(r=0.864,P<0.001);When the lumbar HAP(fat)density was 116.160mg/cm~3 for the diagnosis of osteoporosis threshold,the sensitivity was 81%,specificity was 88%。The area under the ROC curve is 0.931(95%confidence interval is 0.881 to 0.981)。Conclusion:Lumbar HAP(fat)density was highly related to bone mineral density of dual energy X-ray absorptiometry(DXA),The material decomposition technique of Gemstone spectral CT can accurately reflect the changes of bone mineral density of lumbar spine,When the HAP(fat)density of the lumbar spine is 116.160 mg/cm~3 as the threshold for diagnosis of osteoporosis,Gemstone spectral CT can be used as a new method for diagnosis of osteoporosis,It is of high value for the prevention of osteoporosis and the early accurate diagnosis.