Division of Diagnostic and Interventional Neuroradiology, Department of Radiology, University of Basel Hospital, Petersgraben 4, 4031 Basel, Switzerland.
J Neurol. 2013 Apr;260(4):969-74. doi: 10.1007/s00415-012-6733-x. Epub 2012 Nov 9.
The purpose of this ethics approved trial was to correlate quantitative MRI with functional abilities in both ambulant and non-ambulant Duchenne muscular dystrophy (DMD). Twenty patients with genetically confirmed DMD were recruited. Physical assessment was performed using the motor function measurement (MFM) scale. Axial 3T MRI scans of the thighs were acquired using T1-weighted in- and opposed-phase images (TR = 20 ms, TE1 = 2.45 ms, TE2 = 3.68 ms, flip angle = 15°) to calculate the relative fat fraction according to the two-point Dixon method in the knee extensors, flexors, and adductor muscles. The average MFM was 65.3 % and correlated negatively to age (r (2) = 0.60). Overall mean fat fraction correlated positively to age (r (2) = 0.51-0.64). An average of 5 % increase in mean fat fraction per year was calculated. Mean fat fraction of the quadriceps showed a high negative correlation (r (2) = 0.93) to the D1 (standing position and transfers) component of the MFM. A cutoff for mean fat fraction of 50 % predicted loss of ambulation with a sensitivity of 100 % and a specificity of 91 %. Therefore, quantitative muscle MRI seems to be a promising endpoint for short clinical trials evaluating the effect of newer treatments on the time of loss of ambulation in DMD.
这项经过伦理批准的试验旨在将定量 MRI 与行走和非行走的杜氏肌营养不良症（DMD）患者的功能能力相关联。共招募了 20 名经基因证实患有 DMD 的患者。使用运动功能测量（MFM）量表进行身体评估。在大腿处进行轴向 3T MRI 扫描，使用 T1 加权的同相位和反相位图像（TR = 20ms，TE1 = 2.45ms，TE2 = 3.68ms，翻转角 = 15°），根据两点 Dixon 方法计算膝关节伸肌、屈肌和内收肌的相对脂肪分数。平均 MFM 为 65.3%，与年龄呈负相关（r²=0.60）。总体平均脂肪分数与年龄呈正相关（r²=0.51-0.64）。计算出每年平均脂肪分数增加 5%。股四头肌的平均脂肪分数与 MFM 的 D1（站立和转移）成分呈高度负相关（r²=0.93）。平均脂肪分数为 50%的截定点可预测失去行走能力，其灵敏度为 100%，特异性为 91%。因此，定量肌肉 MRI 似乎是评估新型治疗方法对 DMD 患者丧失行走能力时间影响的短期临床试验的有前途的终点。
