Egger Micaela, Spence J David, Fenster Aaron, Parraga Grace
Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
Ultrasound Med Biol. 2007 Jun;33(6):905-14. doi: 10.1016/j.ultrasmedbio.2007.01.013. Epub 2007 Apr 18.
Carotid atherosclerotic lesions are a major cause of stroke and the identification and quantification of such lesions in patients is important for the development of a better understanding of atherogenesis in high risk populations and for the design of studies to assess treatment efficacy. Our objective was to develop and validate a new three-dimensional ultrasound (3DUS) measurement or phenotype of carotid atherosclerosis, vessel wall volume (VWV), which is a three-dimensional measurement of vessel wall thickness and plaque within the carotid arteries measured in 3DUS images. To assess both intraobserver and interscan variability, 3DUS images were acquired from the right and left carotid arteries of ten subjects with carotid atherosclerosis scanned twice within a period of 2 wk. For both VWV and total plaque volume (TPV), an expert observer performed five measurement trials of all images acquired at baseline scan and 2-wk rescan with a 5-d period between measurement trials for images. Images were re-randomized for each measurement trial and both TPV and VWV were measured by observers who were blinded to subject identification for each time-point measurement. Coefficients of variation (COV) and intraclass correlation coefficients (ICC), for VWV measurements indicated higher intraobserver (scan COV = 4.6% ICC = 0.95, rescan COV = 3.4%, ICC = 0.96) and interscan reproducibility (COV = 5.7%, ICC = 0.85) than TPV measurements (intraobserver variability scan COV = 22.7% ICC = 0.85, rescan COV = 21.1% ICC = 0.88 and interscan variability, COV = 31.1%, ICC = 0.83), although absolute variances for both phenotypes were very similar (VWV = 90 mm3, TPV = 80 mm3).
颈动脉粥样硬化病变是中风的主要原因，对患者此类病变进行识别和定量，对于更好地了解高危人群的动脉粥样硬化发病机制以及设计评估治疗效果的研究具有重要意义。我们的目标是开发并验证一种新的颈动脉粥样硬化三维超声（3DUS）测量方法或表型——血管壁体积（VWV），它是在3DUS图像中测量的颈动脉内血管壁厚度和斑块的三维测量值。为了评估观察者内和扫描间的变异性，在2周内对10名患有颈动脉粥样硬化的受试者的左右颈动脉进行两次扫描，获取3DUS图像。对于VWV和总斑块体积（TPV），一名专家观察者对基线扫描和2周重新扫描时获取的所有图像进行了五次测量试验，每次测量试验之间间隔5天。每次测量试验时图像重新随机排列，TPV和VWV均由对每个时间点测量的受试者身份不知情的观察者测量。VWV测量的变异系数（COV）和组内相关系数（ICC）表明，观察者内（扫描COV = 4.6%，ICC = 0.95；重新扫描COV = 3.4%，ICC = 0.96）和扫描间的可重复性（COV = 5.7%，ICC = 0.85）高于TPV测量（观察者内变异性扫描COV = 22.7%，ICC = 0.85；重新扫描COV = 21.1%，ICC = 0.88；扫描间变异性COV = 31.1%，ICC = 0.83），尽管两种表型的绝对方差非常相似（VWV = 90 mm³，TPV = 80 mm³）。
