Dwyer J H, Sun P, Kwong-Fu H, Dwyer K M, Selzer R H
Department of Preventive Medicine, Institute for Health Promotion and Disease Prevention Research, University of Southern California School of Medicine, Los Angeles 90033-4500, USA.
Ultrasound Med Biol. 1998 Sep;24(7):981-7. doi: 10.1016/s0301-5629(98)00069-6.
Common carotid artery (CCA) intima-media thickness (IMT) from B-mode ultrasound is a widely used measure of early atherosclerosis. This study evaluated within- and between-sonographer reproducibility of automated edge-tracking IMT using a low-cost mobile scanner. B-mode images of the left and right CCA were acquired on two occasions (interval of 2-14 days) by two sonographers for 38 subjects, aged 31-75 y. Reproduciblity error was measured as the mean absolute difference (MAD+/-SEM) and the standard deviation of differences (SDdelta) between repeated measurements. Within-sonographer (MAD=0.027+/-0.006 mm; SDdelta=0.044 mm) and between-sonographer errors (MAD=0.041+/-0.008 mm; SDdelta=0.064) in IMT (mean=0.74, SD=0.14) of a single artery were small compared to those of other protocols. Combined averaging across both body positions and arteries reduced intersonographer MAD by 47% (MAD=0.022+/-0.003 mm; SDdelta=0.029 mm). These data demonstrate that the proposed IMT protocol reduces reproducibility error by more than 50% relative to several protocols used in other major studies.
B 型超声测量的颈总动脉（CCA）内膜中层厚度（IMT）是一种广泛应用于早期动脉粥样硬化的测量方法。本研究使用低成本移动扫描仪评估了超声检查医师内部和之间自动边缘跟踪 IMT 的可重复性。两名超声检查医师在两个时间点（间隔 2 - 14 天）为 38 名年龄在 31 - 75 岁的受试者采集左右 CCA 的 B 型图像。可重复性误差通过重复测量之间的平均绝对差（MAD±SEM）和差值标准差（SDdelta）来衡量。与其他方案相比，单一动脉 IMT（平均值 = 0.74，标准差 = 0.14）的超声检查医师内部误差（MAD = 0.027±0.006 mm；SDdelta = 0.044 mm）和超声检查医师之间的误差（MAD = 0.041±0.008 mm；SDdelta = 0.064）较小。对身体位置和动脉进行联合平均可使超声检查医师之间的 MAD 降低 47%（MAD = 0.022±0.003 mm；SDdelta = 0.029 mm）。这些数据表明，相对于其他主要研究中使用的几种方案，所提出的 IMT 方案可将可重复性误差降低 50%以上。
