Koo K H, Dussault R, Kaplan P, Kim R, Ahn I O, Christopher J, Song H R, Wang G J
Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, USA.
Radiology. 1998 Mar;206(3):745-8. doi: 10.1148/radiology.206.3.9494495.
To determine the normal chronologic changes in fatty marrow conversion of the proximal femoral metaphysis at magnetic resonance (MR) imaging.
The "marrow conversion index," (signal intensity of the proximal femoral metaphysis divided by signal intensity of the greater trochanter) x 100, was measured in 182 hips of 91 patients who had no evidence of osteonecrosis or diseases involving bone marrow, no history of steroid treatment, and no other risk factors for osteonecrosis. The results were evaluated according to patient age and sex.
The index showed a progressive linear increase with age regardless of sex. The index was 65.4% +/- 5.6 (standard deviation) in patients aged 15-19 years and increased monotonously with age to 87.5% +/- 7.0 in patients aged 60-79 years. Simple linear regression of the index according to age group showed that the marrow conversion index is roughly equal to 63 + 4 x Z (p < .001), where Z is 1.5 for patients aged 15-19 years, 2.0 for patients aged 20-29 years, 3.0 for patients aged 30-39 years, 4.0 for patients aged 40-49 years, 5.0 for patients aged 50-59 years, and 6.0 for patients aged 60-79 years.
There is a linear association of marrow conversion index and age. The estimating equation may provide baseline information for the marrow conversion index.
确定磁共振成像（MR）检查时股骨近端干骺端脂肪骨髓转换的正常时间性变化。
对91例患者的182髋进行测量，这些患者无骨坏死或累及骨髓疾病的证据，无类固醇治疗史，也无其他骨坏死危险因素。测量“骨髓转换指数”，即（股骨近端干骺端信号强度除以大转子信号强度）×100，并根据患者年龄和性别评估结果。
无论性别，该指数均随年龄呈渐进性线性增加。15 - 19岁患者的指数为65.4%±5.6（标准差），并随年龄单调增加，60 - 79岁患者的指数为87.5%±7.0。根据年龄组对指数进行简单线性回归分析显示，骨髓转换指数大致等于63 + 4×Z（p <.001），其中15 - 19岁患者Z为1.5，20 - 29岁患者Z为2.0，30 - 39岁患者Z为3.0，40 - 49岁患者Z为4.0，50 - 59岁患者Z为5.0，60 - 79岁患者Z为6.0。
骨髓转换指数与年龄呈线性相关。该估算方程可为骨髓转换指数提供基线信息。
