The DE50-MD canine model of Duchenne muscular dystrophy (DMD) has a dystrophin gene splice site mutation causing deletion of exon 50, an out-of-frame transcript and absence of dystrophin expression in striated muscles. We hypothesized that the musculoskeletal phenotype of DE50-MD dogs could be detected using Magnetic Resonance Imaging (MRI), that it would progress with age and that it would reflect those in other canine models and DMD patients. 15 DE50-MD and 10 age-matched littermate wild type (WT) male dogs underwent MRI every 3 months from 3 to 18 months of age. Normalized muscle volumes, global muscle T2 and ratio of post- to pre-gadolinium T1-weighted SI were evaluated in 7 pelvic limb and 4 lumbar muscles bilaterally. DE50-MD dogs, compared to WT, had smaller volumes in all muscles, except the cranial sartorius; global muscle T2 was significantly higher in DE50-MD dogs compared to WT. Muscle volumes plateaued and global muscle T2 decreased with age. Normalized muscle volumes and global muscle T2 revealed significant differences between groups longitudinally and should be useful to determine efficacy of therapeutics in this model with suitable power and low sample sizes. Musculoskeletal changes reflect those of DMD patients and other dog models.

杜氏肌营养不良症 (DMD) 的 DE50-MD 犬模型具有肌营养不良蛋白基因剪接位点突变，导致外显子 50 缺失、框架外转录物和横纹肌中肌营养不良蛋白表达缺失。我们假设可以使用磁共振成像 (MRI) 检测 DE50-MD 犬的肌肉骨骼表型，它会随着年龄的增长而进展，并且会反映其他犬模型和 DMD 患者的肌肉骨骼表型。15 只 DE50-MD 和 10 只年龄匹配的同窝野生型 (WT) 雄性犬从 3 到 18 个月大，每 3 个月接受一次 MRI。对 7 个骨盆肢体和 4 个双侧腰肌的标准化肌肉体积、整体肌肉 T2 和钆前与钆前 T1 加权 SI 的比率进行了评估。与 WT 相比，DE50-MD 犬的所有肌肉体积都较小，除了颅缝匠肌；与 WT 相比，DE50-MD 犬的整体肌肉 T2 显着更高。随着年龄的增长，肌肉体积趋于稳定，整体肌肉 T2 下降。归一化肌肉体积和整体肌肉 T2 揭示了纵向各组之间的显着差异，应该有助于确定该模型中具有合适功效和低样本量的治疗效果。肌肉骨骼变化反映了 DMD 患者和其他狗模型的变化。