【摘要】 目的:应用双能X线检测(dual energy X-ray absorptiometry,DXA)、多层螺旋CT骨矿容积含量测定(quantitative computed tomography,QCT)和磁共振化学位移成像(chemical shift i maging,CSI)检查大鼠全身骨及骨松质,结合骨髓脂肪含量病理结果,探讨在生理状态下利用不同影像学方法检测骨松质骨量和骨髓脂水含量变化,为骨松质变化的早期诊断提供影像学依据。方法:SD大鼠(12周龄)雌雄各30只,完全随机化方法进行:假手术(雌雄各10只);去势手术(雌雄各20只)。在手术后第12周和第16周各取半数进行影像学检查,得到DXA、QCT和化学位移率(chemical shift ratio,CSR),结合光镜下骨松质HE染色切片得到的骨髓脂肪含量(fat fraction,%FF),进行对比分析。结果:在50只具有有效研究数据的大鼠中,骨髓高脂肪组大鼠的DXA(0.310±0.014mg/cm2)、QCT(427.88±39.25mg/cm3)和CSR(0.673±0.167)均比骨髓低脂肪组的(DXA为0.320±0.014mg/cm2、QCT为503.86±79.02mg/cm3、CSR为0.828±0.245)要低(P<0.05)。经Pearson检验,DXA与QCT间相关性(P=0.021)及CSR与QCT间相关性(P=0.016)都有统计学意义;DXA与CSR间的相关性(P=0.254)没有统计学意义。结论:骨松质骨髓脂肪含量增加,DXA和QCT就减少,相应的骨髓化学位移率降低。化学位移成像可以无创伤、无辐射的检测骨髓脂肪含量的变化,间接推测骨松质骨矿含量的变化。更多还原

【Abstract】 Purpose:To assess the capability of DXA,QCT and CSR in predicting the mechanical compentence of bone in healthy and osteopentic rats with the result of the bone marrow lipid content respectively.Methods:Thirty male SD rats and 30 female rats at 12 month old were randomly divided(using completely randomized grouping method) into groups:20 ovariectomy female rats,20 archidectomy male rats and 20 sham-operated rats.Three parameters(DXA,QCT,CSR) were measured for all. At the end of experiments,rats were killed and histopathological examination was performed on the ilium bone. Results:In the fifty rats with full three parameters,the high-fat marrow group’s DXA was 0.310±0.014mg/cm2,QCT was 427.88±39.25mg/cm3,CSR was0.673±0.167;the low-fat marrow group’s DXA was 0.320±0.014mg/cm2,QCT was27.88±39.25mg/cm3,CSR was 0.673±0.167.In the model of the spongy bone ,QCT was correlated with DXA and CSR.But the interaction between DXA and CSR was not significant.Conclusion:In the model of spongy bone,when the bone marrow lipid water content increased,the DXA,QCT and CSR all decreased.CSR could be a optimal predictor for the bone marrow lipid content and a indirect prediector for the BMD,without hurts and radiation.更多还原