1 Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039.
2 Department of Radiology, University of Texas Medical School at Houston, Houston, TX.
AJR Am J Roentgenol. 2015 Aug;205(2):W207-15. doi: 10.2214/AJR.14.13754.
The purpose of this study was to validate derived T2 maps as an objective measure of muscular fat for discrimination between boys with Duchenne muscular dystrophy (DMD) and healthy boys.
Forty-two boys with DMD (mean age, 9.9 years) and 31 healthy boys (mean age, 11.4 years) were included in the study. Age, body mass index, and clinical function scale grade were evaluated. T1-weighted MR images and T2 maps with and without fat suppression were obtained. Fatty infiltration was graded 0-4 on T1-weighted images, and derived T2 fat values (difference between mean T2 values from T2 maps with and without fat suppression) of the gluteus maximus and vastus lateralis muscles were calculated. Group comparisons were performed. The upper limit of the 95% reference interval of T2 fat values from the control group was applied.
There was no significant difference in age or body mass index between groups. All healthy boys and 19 boys (45.2%) with DMD had a normal clinical function scale grade. Grade 1 fatty infiltration was seen in 90.3% (gluteus maximus) and 71.0% (vastus lateralis) of healthy boys versus 33.3% (gluteus maximus) and 52.4% (vastus lateralis) of boys with DMD. T2 fat values of boys with DMD were significantly longer than in the control group (p < 0.001). Using a 95% reference interval for healthy boys for the gluteus maximus (28.3 milliseconds) allowed complete separation from boys with DMD (100% sensitivity, 100% specificity), whereas the values for the vastus lateralis (7.28 milliseconds) resulted in 83.3% sensitivity and 100% specificity.
Measurement of muscular fat with T2 maps is accurate for differentiating boys with DMD from healthy boys.
本研究旨在验证衍生 T2 图谱作为一种客观的肌肉脂肪测量指标，用于区分杜氏肌营养不良症（DMD）男孩和健康男孩。
本研究纳入了 42 名 DMD 男孩（平均年龄 9.9 岁）和 31 名健康男孩（平均年龄 11.4 岁）。评估了年龄、体重指数和临床功能量表等级。获得了 T1 加权磁共振图像和有/无脂肪抑制的 T2 图谱。在 T1 加权图像上对脂肪浸润进行 0-4 级分级，并计算臀大肌和股外侧肌的衍生 T2 脂肪值（T2 图谱有/无脂肪抑制时平均 T2 值之间的差异）。进行了组间比较。应用对照组 T2 脂肪值 95%参考区间上限。
两组间年龄或体重指数无显著差异。所有健康男孩和 19 名 DMD 男孩（45.2%）均具有正常的临床功能量表等级。90.3%（臀大肌）和 71.0%（股外侧肌）的健康男孩存在 1 级脂肪浸润，而 33.3%（臀大肌）和 52.4%（股外侧肌）的 DMD 男孩存在脂肪浸润。DMD 男孩的 T2 脂肪值明显长于对照组（p<0.001）。使用健康男孩臀大肌的 95%参考区间（28.3 毫秒）可以完全将 DMD 男孩与对照组区分开来（100%敏感性，100%特异性），而股外侧肌的 T2 脂肪值（7.28 毫秒）的敏感性为 83.3%，特异性为 100%。
使用 T2 图谱测量肌肉脂肪对于区分 DMD 男孩和健康男孩是准确的。
