Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zürich, Switzerland.
Deusto Institute of Technology, University of Deusto/IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
Medicine (Baltimore). 2021 May 28;100(21):e25947. doi: 10.1097/MD.0000000000025947.
To compare the speed of propagation of ultrasound (US) waves (SoS) of the lower leg with the clinical reference standard computed tomography (CT) at the level of lumbar vertebra 3 (L3) for muscle loss assessment. Both calf muscles of 50 patients scheduled for an abdominal CT were prospectively examined with ultrasound. A plexiglas-reflector located on the opposite side of the probe with the calf in between was used as a timing reference for SoS (m/s). CT measurements were performed at the level of L3 and included area (cm2) and attenuation (HU) of the psoas muscle, abdominal muscles, subcutaneous fat, visceral fat and abdominal area. Correlations between SoS, body mass index (BMI) and CT were determined using Pearson's correlation coefficient. Based on reported CT sarcopenia threshold values, receiver operating characteristic (ROC) analysis was performed for SoS. Inter-examiner agreement was assessed with the median difference, inter-quartile range (IQR) and intraclass correlation coefficients. SoS of the calf correlated moderately with abdominal muscle attenuation (r = 0.48; P < .001), psoas muscle attenuation (r = 0.40; P < .01), abdominal area (r = -0.44; P < .01) and weakly with subcutaneous fat area (r = -0.37; P < .01). BMI correlated weakly with psoas attenuation (r = -0.28; P < .05) and non-significantly with abdominal muscle attenuation. Normalization with abdominal area resulted in moderate correlations with abdominal muscle area for SoS (r = 0.43; P < .01) and BMI (r = -0.46; P < .001). Based on sarcopenia threshold values for skeletal muscle attenuation (SMRA), area under curve (AUC) for SoS was 0.724. Median difference between both examiners was -3.4 m/s with IQR = 15.1 m/s and intraclass correlation coefficient = 0.794. SoS measurements of the calf are moderately accurate based on CT sarcopenia threshold values, thus showing potential for muscle loss quantification.
为了比较小腿的超声（US）波速度（SoS）与腰椎 3 水平的临床参考标准计算机断层扫描（CT）在肌肉减少评估方面的速度。前瞻性地对 50 名计划进行腹部 CT 的患者的小腿肌肉进行了超声检查。在探头的对面放置一个有机玻璃反射器，将小腿夹在中间，用作 SoS（m/s）的计时参考。在 L3 水平进行 CT 测量，包括腰大肌、腹部肌肉、皮下脂肪、内脏脂肪和腹部面积的面积（cm2）和衰减（HU）。使用 Pearson 相关系数确定 SoS、体重指数（BMI）和 CT 之间的相关性。根据报告的 CT 肌肉减少症阈值值，对 SoS 进行接收者操作特征（ROC）分析。使用中位数差异、四分位距（IQR）和组内相关系数评估观察者间的一致性。小腿 SoS 与腹部肌肉衰减（r = 0.48；P < 0.001）、腰大肌衰减（r = 0.40；P < 0.01）、腹部面积（r = -0.44；P < 0.01）呈中度相关，与皮下脂肪面积呈弱相关（r = -0.37；P < 0.01）。BMI 与腰大肌衰减呈弱相关（r = -0.28；P < 0.05），与腹部肌肉衰减无显著相关性。用腹部面积归一化后，SoS 与腹部肌肉面积（r = 0.43；P < 0.01）和 BMI（r = -0.46；P < 0.001）呈中度相关。基于骨骼肌衰减的肌肉减少症阈值值（SMRA），SoS 的曲线下面积（AUC）为 0.724。两位观察者之间的中位数差异为-3.4 m/s，四分位距为 15.1 m/s，组内相关系数为 0.794。根据 CT 肌肉减少症阈值，小腿 SoS 测量具有中等准确性，因此具有肌肉减少定量的潜力。
