Li Min, Guo Ruiqian, Tang Xinyi, Huang Songya, Qiu Li
Department of Medical Ultrasound, West China Hospital of Sichuan University, Chengdu, China.
Quant Imaging Med Surg. 2023 Jan 1;13(1):428-440. doi: 10.21037/qims-22-423. Epub 2022 Nov 22.
Polymyositis (PM) and dermatomyositis (DM) are two common types of idiopathic inflammatory myopathy and can lead to a poor prognosis and quality of life. We designed this cross-sectional study to investigate the abilities of high-frequency ultrasound (HFUS) and shear wave elastography (SWE) to assess muscle properties in patients with PM and DM and to distinguish healthy muscles from diseased muscles with PM and DM.
A total of 60 patients (26 PM cases and 34 DM cases) and 65 matched healthy volunteers were continuously included in the case and control groups, respectively. For the bilateral deltoid, biceps brachii, rectus femoris, and vastus lateralis, the muscle thickness, echo intensity, and longitudinal shear wave velocity (SWV) of all participants were measured using HFUS and SWE. The intra- and interobserver reliability of SWV measurements of patients with PM and DM and the receiver operating characteristic curve for HFUS and SWE for PM and DM were analyzed.
Patients with PM and DM had significantly decreased muscle thickness and increased muscle echo intensity compared to healthy controls (P<0.001). The patients' and healthy participants' deltoid, biceps brachii, rectus femoris, and vastus lateralis thickness was 19.75 and 23.00 mm, 20.45 and 22.80 mm, 18.40 and 20.20 mm, and 20.00 and 22.80 mm, respectively. Except for the biceps brachii, the mean SWV in the longitudinal orientation in patients with PM and DM significantly decreased (P<0.01). The mean SWV of the patients' and healthy participants' deltoid, rectus femoris, and vastus lateralis was 2.47 and 2.57 m/s, 1.73 and 1.87 m/s, and 1.57 and 1.77 m/s, respectively. Excellent intra- and interobserver reliability of SWV measurements on the deltoid and rectus femoris of PM and DM patients were found (intraclass correlation coefficient >0.95; P<0.001). The diagnostic performance of echo intensity in lower-extremity proximal muscles for PM and DM was excellent [area under the curve (AUC) >0.9]. The thickness of most muscles displayed moderate diagnostic performance (the AUC ranged from 0.700 to 0.775). The SWV of the vastus lateralis showed a stable performance (AUC =0.741). The combined diagnostic performance of echo intensity and thickness and the combined diagnostic performance of the 3 indicators were relatively high (the AUC ranged from 0.871 to 0.936 and from 0.898 to 0.938, respectively). Muscle thickness and echo intensity showed statistical differences in different disease stages of PM and DM (P'<0.01).
HFUS and SWE may serve as imaging biomarkers for the diagnosis of PM and DM by detecting abnormal muscle thinning, enhanced muscle echo intensity, and reduced muscle SWV.
多发性肌炎（PM）和皮肌炎（DM）是特发性炎性肌病的两种常见类型，可导致不良预后和生活质量下降。我们设计了这项横断面研究，以调查高频超声（HFUS）和剪切波弹性成像（SWE）评估PM和DM患者肌肉特性以及区分健康肌肉与PM和DM患病肌肉的能力。
病例组和对照组分别连续纳入60例患者（26例PM患者和34例DM患者）和65名匹配的健康志愿者。对于双侧三角肌、肱二头肌、股直肌和股外侧肌，使用HFUS和SWE测量所有参与者的肌肉厚度、回声强度和纵向剪切波速度（SWV）。分析了PM和DM患者SWV测量的观察者内和观察者间可靠性以及HFUS和SWE对PM和DM的受试者工作特征曲线。
与健康对照组相比，PM和DM患者的肌肉厚度显著降低，肌肉回声强度增加（P<0.001）。患者和健康参与者的三角肌、肱二头肌、股直肌和股外侧肌厚度分别为19.75和23.00mm、20.45和22.80mm、18.40和20.20mm以及20.00和22.80mm。除肱二头肌外，PM和DM患者纵向方向的平均SWV显著降低（P<0.01）。患者和健康参与者三角肌、股直肌和股外侧肌的平均SWV分别为2.47和2.57m/s、1.73和1.87m/s以及1.57和1.77m/s。发现PM和DM患者三角肌和股直肌SWV测量具有出色的观察者内和观察者间可靠性（组内相关系数>0.95；P<0.001）。下肢近端肌肉回声强度对PM和DM的诊断性能优异[曲线下面积（AUC）>0.9]。大多数肌肉的厚度显示出中等诊断性能（AUC范围为0.700至0.775）。股外侧肌的SWV表现稳定（AUC =0.741）。回声强度和厚度的联合诊断性能以及三个指标的联合诊断性能相对较高（AUC分别范围为0.871至0.936和0.898至0.938）。肌肉厚度和回声强度在PM和DM的不同疾病阶段存在统计学差异（P'<0.01）。
HFUS和SWE可通过检测异常的肌肉变薄、增强的肌肉回声强度和降低的肌肉SWV作为诊断PM和DM的影像学生物标志物。
