核素骨显像与骨密度关系的动物试验探讨

The investigation of the relationship between radionuclide bone scintigraphy and bone mineral density by animal study

目的探讨核素“99mTc．MDP”骨显像对兔骨质疏松模型半定量测定与骨密度的关系。方法实验中使用健康雌性新西兰兔，用肌肉注射地塞米松磷酸钠针剂（DX）诱导制作骨质疏松模型。研究设立正常对照组（A组），骨质疏松对照组（B组）和“云克”治疗组（c组），每组各8只。“云克”治疗方法：1mg／kg·3ml行兔耳静脉推注，每周1次，总疗程为16周。6周后取各组实验兔腰椎、股骨头行骨密度、骨力学试验，病理细胞学、骨形态计量以及x线、CT摄片和核素骨骼扫描（ROI比值）、血清骨ALP、BGP测定，分析检测数据与骨密度的关系。结果骨质疏松动物模型的骨病理切片显示股骨头关节表面软骨破坏，骨小梁稀疏、断裂等骨破坏表现。核素骨骼显像、骨密度、骨力学、骨形态计量、骨ALP、BGP结果在正常对照组和骨质疏松对照组间差异存在显著性（P〈0．01），表明骨质疏松模型建立。A、B、C组进行实验室相同的检测指标比较，显示腰椎、股骨头和膝关节的放射性摄取量的改变与骨密度、骨力学、骨计量、骨ALP和BGP的改变与3组实际情况基本相匹配。各实验数据和细胞学、骨骼显像的变化存在相应的同步性。结论核素骨骼显像的半定量测定可以结合骨密度对不同个体的真实骨代谢变化进行互补分析。分析正常对照组、骨质疏松对照组的骨扫描图像，进行半定量分析：第3腰椎，尾椎〉1．78为骨质疏松，〈1．32为骨代谢正常；股骨头／尾椎〉1．76为骨质疏松，〈1．17为骨代谢正常。“云克”治疗的c组的检测结果均在正常范围内。

Objective To investigate the relationship between hemi-quantitation ＂99mTc-MDP＂bone scan and bone mineral density in rabbit bone osteoporosis model. Methods Healthy female New Zealand rabbits were used in this experiment. Osteoporosis model was induced by dexamethasone sodium phosphate intramuscular injection. Normal control group（A）, osteoporosis group（B） and ＂YUNKE＂ therapy group（C） was set up in the study. Each group contained 8 rabbits. ＂YUNKE＂ injection was administrated i.v. to the left-ear at the dose of 1 mg· kg-1 . 3 ml-1 , once a week and totally for 16 weeks. After 6 weeks, lumbar and femoral head underwent serial essays, including bone mineral density, bone mechanics, pathology, Bone histomorphometry, X-ray, CT and ＂99m Tc-MDP＂ bone scan region of interest（ROI） ration. Serum bone-alkaline phosphatase （B-ALP）, and bone gla protein （BGP） were measured as well. Results The pathology test showed significant osteoclasis, cartilage disrupt of femoral head and bone trabeeula of rarefaction in the osteoporosis group. Significant differences exist in normal control group and osteoporosis group, appearing in ROI ration of bone scan, bone mineral density, mechanics, norphometry and serum B-ALP, BGP concentrations （P 〈 0.01 ）. This proved the successful establishment of osteoporosis animal model, we compared series of tests in Normal control Group, osteoporosis Group, and ＂YUNKE＂ therapy Group. The results showed that the radioactive uptake value in lumbar, femoral head and articular genu consist with bone mineral density, mechanics, norphometry and serum B-ALP,BGP concentrations. Conclusion Hemi-quantitation ＂99mTc-MDP＂ bone scan assisted with bone mineral density can provide important information on actual bone metabolism. Using hemi-quantitation technics, we suggested that the third lumbar to coccyx vertebra radioactive uptake ratio （I3/C ratio） 〉 1.78, osteoporosis; 1.3/C ratio 〈 1.32, normal, the femoral head to coccyx vertebra radioactive uptake ratio （FH/C ratio） 〉 1.76, osteoporosis; FH/C ratio 〈 1.17, normal. The radioactive uptake ratio of Yunke therapy group falls in the normal range.