Objectives: To summarize the skeletal muscle magnetic resonance imaging (MRI) features of the lower limbs in common subtypes of muscular dystrophy (MD) and the experience in the application of MRI in the diagnosis of MD.
Methods: A total of 48 children with MD who were diagnosed by genetic testing were enrolled as subjects. The muscle MRI features of the lower limbs were analyzed. Cumulative fatty infiltration score was calculated for each subtype, and the correlation of cumulative fatty infiltration score with clinical indices was analyzed for Duchenne muscular dystrophy (DMD).
Results: DMD was characterized by the involvement of the gluteus maximus and the adductor magnus. Becker muscular dystrophy was characterized by the involvement of the vastus lateralis muscle. Limb-girdle muscular dystrophy was characterized by the involvement of the adductor magnus, the vastus intermedius, the vastus medialis, and the vastus lateralis muscle. For DMD, the cumulative fatty infiltration score of the lower limb muscles was significantly correlated with age, course of the disease, muscle strength, and motor function (P<0.05), while it was not significantly correlated with the serum creatine kinase level (P>0.05).
Conclusions: Different subtypes of MD have different MRI manifestations, and MRI may help with the diagnosis and assessment of MD.
目的: 总结肌营养不良（muscular dystrophy，MD）常见亚型下肢肌肉骨骼肌磁共振成像（magnetic resonance imaging，MRI）特点，积累应用MRI协助诊断MD的经验。方法: 选取经基因检测确诊的48例MD患儿为研究对象，分析其下肢肌肉MRI特点，统计各亚型肌肉脂肪浸润累计评分，并分析Duchenne型肌营养不良脂肪浸润累计评分与临床指标的相关性。结果: Duchenne型肌营养不良以臀大肌、大收肌受累为著，Becker型肌营养不良以股外侧肌受累为著，肢带型肌营养不良以大收肌、股中间肌、股内侧肌、股外侧肌受累为著。Duchenne型肌营养不良下肢肌肉脂肪浸润累计评分与年龄、病程、肌肉力量及运动功能明显相关（P<0.05），与血清肌酸激酶无相关性（P>0.05）。结论: 不同亚型MD的MRI表现特点不同，MRI有助于MD的诊断与病情评估。.
Keywords: Child; Diagnosis; Duchenne muscular dystrophy; Magnetic resonance imaging; Muscular dystrophy.