Duchenne型肌营养不良症肌肉磁共振成像脂肪浸润和水肿特点分析

Characteristics of fatty infiltration and edema of muscle MRI in Duchenne muscular dystrophy patients

目的总结Duchenne型肌营养不良症肌肉MRI脂肪浸润和水肿特点。方法共70例诊断明确的Duchenne型肌营养不良症患者均行临床严重程度分级,以及臀部(包括臀大肌、臀中肌、臀小肌、髂腰肌、梨状肌、闭孔内肌、闭孔外肌、阔筋膜张肌、耻骨肌、竖脊肌、腰大肌、髂肌)、大腿(包括大收肌、股薄肌、长收肌、缝匠肌、股直肌、股中间肌、股内侧肌、股外侧肌、股二头肌、半腱肌、半膜肌)和小腿(包括腓肠肌、比目鱼肌、腓骨长肌、胫骨后肌、胫骨前肌、长屈肌、长伸肌、趾长伸肌)共计31块肌肉MRI检查,并采用T1WI脂肪浸润分级和T2WI抑脂成像水肿分级评价肌肉脂肪浸润和水肿程度。结果31块肌肉中30块(96.77%)出现脂肪浸润,23块(74.19%)出现水肿,肌肉脂肪浸润比例高于水肿比例。臀大肌等21块肌肉T1WI脂肪浸润分级≥2级,胫骨后肌等10块肌肉T1WI脂肪浸润分级≤1级;比目鱼肌等5块肌肉T2WI抑脂成像水肿分级3级。Spearman秩相关分析显示,盆带肌群中臀大肌(rs=0.518,P=0.016)、臀中肌(rs=0.528,P=0.014)、臀小肌(rs=0.528,P=0.014)、髂腰肌(rs=0.695,P=0.000)、梨状肌(rs=0.451,P=0.040)、耻骨肌(rs=0.567,P=0.009)、竖脊肌(rs=0.499,P=0.025),大腿肌群中大收肌(rs=0.607,P=0.005)、长收肌(rs=0.547,P=0.013)、股直肌(rs=0.614,P=0.004)、股中间肌(rs=0.566,P=0.009)、股内侧肌(rs=0.522,P=0.018)、股外侧肌(rs=0.503,P=0.024)、股二头肌(rs=0.508,P=0.022),小腿肌群中腓肠肌(rs=0.715,P=0.001)、腓骨长肌(rs=0.571,P=0.017)、胫骨后肌(rs=0.514,P=0.035)T1WI脂肪浸润分级与临床严重程度分级呈正相关,其余肌肉T1WI脂肪浸润分级与临床严重程度分级无关联性(均P>0.05);31块肌肉T2WI抑脂成像水肿分级与临床严重程度分级均无关联性(P>0.05)。结论 Duchenne型肌营养不良症肌肉脂肪浸润与临床严重程度一致性较好,是反映临床严重程度的理想指标,而水肿对临床严重程度的影响需根据肌肉特点个体化分析。

Objective To summarize the characteristics of fatty infiltration and edema of muscleMRI in Duchenne muscular dystrophy（DMD） patients. Methods A total of 70 DMD patients underwentClinical Functional Scale and muscle MRI of the pelvic（gluteus maximus, gluteus medius, gluteus minimus,iliopsoas, piriformis, obturator internus, obturator externus, tensor fasciae latae, pectineus, erector spinae,psoas major muscle, iliacus）, thigh（adductor magnus, gracilis, adductor longus, sartorius, rectus femoris,vastus intermedius, vastus medialis, vastus lateralis, biceps femoris, semitendinosus, semimembranosus） andleg（gastrocnemius, soleus, peroneus longus, tibialis posterior, tibialis anterior, flexor hallucis longus,extensor hallucis longus, extensor digitorum longus）. T1WI fatty infiltration grade and fat suppression T2WIedema grade were performed to analyze the imaging features of fatty infiltration and edema. Results In31 muscles, 30 muscles（96.77%） presented fatty infiltration and 23（74.19%） presented edema. Theoccurrence rate of fatty infiltration was higher than that of edema. A total of 21 muscles including gluteusmaximus, were found T1WI fatty infiltration grades greater than 2, and 10 muscles including tibialisposterior, were less than 1. Five muscles including soleus were found fat suppression T2WI edema grade 3.Spearman rank correlation analysis showed positive correlations between T1WI fatty infiltration grade andClinical Functional Scale in 7 pelvic muscles [gluteus maximus（rs= 0.518, P = 0.016）, gluteus medius（rs=0.528, P = 0.014）, gluteus minimus（rs= 0.528, P = 0.014）, iliopsoas（rs= 0.695, P = 0.000）, piriformis（rs=0.451, P = 0.040）, pectineus（rs= 0.567, P = 0.009）, erector spinae（rs= 0.499, P = 0.025）], 7 thigh muscles[adductor magnus（rs= 0.607, P = 0.005）, adductor longus（rs= 0.547, P = 0.013）, rectus femoris（rs= 0.614,P = 0.004）, vastus intermedius（rs= 0.566, P = 0.009）, vastus medialis（rs= 0.522, P = 0.018）, vastus lateralis（rs= 0.503, P = 0.024）, biceps femoris（rs= 0.508, P = 0.022）] and 3 leg muscles [gastrocnemius（rs= 0.715,P = 0.001）, peroneus longus（rs= 0.571, P = 0.017）, tibialis posterior（rs= 0.514, P = 0.035）]. There was nocorrelation between T1WI fatty infiltration grade and Clinical Functional Scale in other muscles（P〉0.05,for all）. There was no correlation between fat suppression T2WI edema grade and Clinical Functional Scalein all muscles（P〉0.05, for all）. Conclusions Fatty infiltration grade can be well used to assess theseverity of DMD. The role of muscle edema on assessing clinical severity should be analyzed according toindividual muscle characteristics.