Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, PR China.
Department of Hepatobiliary Surgery, Wuhan No. 1 Hospital, Wuhan, Hubei Province, PR China.
Acta Radiol. 2022 Apr;63(4):467-473. doi: 10.1177/0284185121999006. Epub 2021 Feb 27.
Dermatomyositis (DM) and muscular dystrophy are clinically difficult to differentiate.
To confirm the feasibility and assess the accuracy of conventional magnetic resonance imaging (MRI), T2 map, diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI) in the differentiation of DM from muscular dystrophy.
Forty-two patients with DM proven by diagnostic criteria were enrolled in the study along with 23 patients with muscular dystrophy. Conventional MR, T2 map, DTI, and DKI images were obtained in the thigh musculature for all patients. Intramuscular T2 value, apparent diffusion coefficient (ADC), fractional anisotropy (FA), mean diffusivity (MD), and mean kurtosis (MK) values were compared between the patients with DM and muscular dystrophy. Student's t-tests and receiver operating characteristic (ROC) curve analyses were performed for all parameters. values < 0.05 were considered statistically significant.
The intramuscular T2, ADC, FA, MD, and MK values within muscles were statistically significantly different between the DM and muscular dystrophy groups (<0.01). The MK value was statistically significantly different between the groups in comparison with T2 and FA value. As a supplement to conventional MRI, the parameters of MD and MK differentiated DM and muscular dystrophy may be valuable. The optimal cut-off value of ADC and MD values (with respective AUC, sensitivity, and specificity) between DM and muscular dystrophy were 1.698 ×10mm/s (0.723, 54.1%, and 78.1%) and 1.80 ×10mm/s (61.9% and 70.2%), respectively.
Thigh muscle ADC and MD parameters may be useful in differentiating patients with DM from those with muscular dystrophy.
皮肌炎（DM）和肌肉营养不良在临床上难以区分。
证实常规磁共振成像（MRI）、T2 图谱、扩散张量成像（DTI）和扩散峰度成像（DKI）在区分 DM 和肌肉营养不良中的可行性，并评估其准确性。
本研究纳入了 42 例经诊断标准证实的 DM 患者和 23 例肌肉营养不良患者。所有患者均行大腿肌肉常规 MRI、T2 图谱、DTI 和 DKI 检查。比较 DM 和肌肉营养不良患者的肌肉内 T2 值、表观扩散系数（ADC）、各向异性分数（FA）、平均扩散系数（MD）和平均峰度（MK）值。所有参数均采用 Student's t 检验和受试者工作特征（ROC）曲线分析。 值<0.05 为差异有统计学意义。
DM 和肌肉营养不良组肌肉内 T2、ADC、FA、MD 和 MK 值差异有统计学意义（<0.01）。与 T2 和 FA 值相比，MK 值在两组间差异有统计学意义。作为常规 MRI 的补充，MD 和 MK 参数可能有助于区分 DM 和肌肉营养不良。DM 和肌肉营养不良患者 ADC 和 MD 值的最佳截断值（相应 AUC、敏感性和特异性）分别为 1.698×10mm/s（0.723、54.1%和 78.1%）和 1.80×10mm/s（61.9%和 70.2%）。
大腿肌肉 ADC 和 MD 参数有助于区分 DM 和肌肉营养不良患者。
