常规MRI及功能MRI诊断抗肌萎缩蛋白病

目的 探讨常规MRI、DWI、T2-mapping和¹H-MRS诊断抗肌萎缩蛋白病的价值。方法 收集经病理和（或）基因检测确诊的抗肌萎缩蛋白病患者39例（病例组），另纳入12名健康志愿者作为对照组。对研究对象双侧大腿行常规MR、DWI、T2-mapping和¹H-MRS检查，常规MRI时进行肌肉脂肪浸润程度评分，于右股外侧肌选择ROI，测量ADC值、R2值、脂肪分数（FF），比较两组间上述各指标差异；绘制诊断抗肌萎缩蛋白病的ROC曲线，评价诊断效能。结果 常规MRI中92.31%（36/39）肌肉呈不同程度脂肪浸润；臀大肌（36/36，100%）最常受累，脂肪浸润评分最高(2.79±1.38)分];长收肌(12/36,33.33%)最少受累,脂肪浸润评分(0.56±1.07)分]。病例组ADC值和R2值均低于对照组低,FF值高于对照组(P均<0.05)。以脂肪浸润评分0.50分、ADC值1.72×10^-3 mm²/s、R2值6.77 Hz、FF值35.20诊断抗肌萎缩蛋白病,其敏感度和特异度分别为94.10%和100%、82.40%和83.30%、100%和83.30%、35.20%和64.60%,其曲线下面积分别为0.97、0.84、0.95、0.82。结论 常规MRI中脂肪浸润评分及不同功能MRI中ADC值、R2值和FF值诊断抗肌萎缩蛋白病效能高,具有重要临床应用价值。

Conventional MRI and functional MRI in diagnosis of distrophynopathy

Objective To evaluate the value of MRI, DWI, T2-mapping and ¹H-MRS in diagnosis of distrophynopathy. Methods Totally 39 distrophynopathy patients (patient group) confirmed by pathology and (or) gene test and 12 healthy controls (control group) were enrolled. Conventional MRI, DWI, T2 mapping and ¹H-MRS of upper legs was performed. The degree of muscle fat infiltration in conventional MRI was visually scored, and the ADC values, R2 values and fat fraction (FF) values in ¹H-MRS were measured with ROI set on right vastus lateralis muscle. The differences of above parameters between the two groups were compared, and ROC analysis was performed to evaluate the diagnostic efficiency of them. Results Fat infiltration was found in 92.31% (36/39) patients. The most frequently involved muscle was gluteus maximus muscle (36/36, 100%) with highest mean score of 2.79±1.38, and the least frequently involved muscle was adducor longus muscle (12/36, 33.33%) with score of 0.56±1.07. In the patients group, the ADC and R2 were significantly lower and the FF was significantly higher than those in control group (all P<0.05). ROC analysis showed that with muscle fat infiltration score 0.50, ADC 1.72×10^-3 mm²/s, R2 6.77 Hz, FF 35.20 as cut-off value, the diagnostic sensitivity and specificity was 94.10% and 100%, 82.40% and 83.30%, 100% and 83.30%, 35.20% and 64.60%, and the area under the ROC curve was 0.97, 0.84, 0.95 and 0.82, respectively. Conclusion Fat infiltration score in conventional MRI, ADC value in DWI, R2 value in T2-mapping scanning and FF value in ¹H-MRS has high efficiency in diagnosis of distrophynopathy, with important clinical application value.