磁共振成像定量评估不同骨密度正常成年人脊椎骨髓脂肪含量的价值研究

Study on the value of MRI quantitative assessment for the fat content of the spinal bone marrow of normal adults with different bone mineral densities

目的:探讨磁共振成像(MRI)定量评估不同骨密度正常成年人脊柱骨髓脂肪含量的应用价值。方法:选取医院进行健康体检的80名成年人,均行双能X射线吸收检测及脊柱MRI检查,以双能X射线吸收法(DXA)检测T值为骨密度测量的“金标准”,根据T值评分(T值评分≤-2.5)将其分为骨质疏松组(25名)、低骨量组(21名)和正常骨量组(34名),以MRI定量评估各颈椎、胸椎及腰椎骨髓脂肪含量,分析骨密度与脊椎骨髓脂肪含量相关性。结果:正常骨量组、低骨量组和骨质疏松组不同性别受检者骨密度依次降低,脊椎骨髓脂肪含量依次升高,脂相信号强度依次升高,3组比较差异有统计学意义(F_(女性)=38.267,F=326.233,F=156.378;F_(男性)=46.478,F=377.463,F=232.694;P<0.05);年龄段在30~39岁、40~49岁、50~59岁以及60~69岁时,骨密度随年龄增大而降低,骨髓脂肪含量随年龄增大而升高,脂相信号强度随年龄增大而升高,差异有统计学意义(F=26.580,F=93.046,F=59.729;P<0.05)。Pearson相关性分析显示,骨髓脂肪含量与骨密度呈显著负相关(r=-0.566,P<0.05),与年龄呈显著正相关(r=0.721,P<0.05)。结论:MRI通过测定不同骨密度脊椎脂肪含量的变化,对预测骨质疏松具有一定的评估价值。

Objective:To explore the application value of the quantitative assessment of magnetic resonance imaging(MRI)for the fat content of spinal bone marrow of normal adults with different bone mineral densities.Methods:A total of 80 normal adults who underwent health physical examination were selected,and all of them underwent dual-energy X-ray absorption testing and spine MRI examination.The tested T value of dual-energy X-ray absorption was used as the"gold standard"for measuring bone mineral density.According to the scores of T values(T score≤-2.5),they were divided into osteoporosis group(25 cases),low bone mass group(21 cases)and normal bone mass group(34 cases).MRI was used to quantitatively assess the fat contents of the spinal bone marrow of each cervical vertebrae,thoracic vertebrae and lumbar vertebrae,and to analyze the correlation between bone mineral density and the fat content of spinal bone marrow.Results:The bone mineral densities of subjects with different genders of normal bone mass group,low bone mass group and osteoporosis group decreased successively,and the fat contents of the spinal bone marrows of them increased successively,and the signal intensities of lipid phases of them increased successively,and the differences of them among three groups were significant(F_(female)=38.267,F=326.223,F=156.378,F_(male)=46.478,F=377.463,F=232.694,P<0.05),respectively.The bone mineral densities decreased with increasing of age,and the fat contents of bone marrow enhanced with the increasing of age,and the signal intensities of lipid phases enhanced with the increasing of age when the age groups of them were respectively 30-39 years old,40-49 years old,50-59 years old and 60-69 years old,and the differences were significant(F=26.580,F=93.046,F=59.729,P<0.05),respectively.Pearson correlation analysis showed that the fat content of spinal bone marrow was significantly negative correlation with bone mineral density(r=-0.566,P<0.05),and it was significantly positive correlation with age(r=0.721,P<0.05).Conclusion:MRI has certain assessment value in predicting osteoporosis through measures the changes of the fat contents of the spine with different bone mineral density,which appears negative correlation with bone mineral density.