Hiro T, Leung C Y, Russo R J, Moussa I, Karimi H, Farvid A R, Tobis J M
Division of Cardiology, University of California, Irvine, Orange 92668-3298, USA.
Am J Card Imaging. 1996 Oct;10(4):209-18.
Different intravascular ultrasound (IVUS) systems vary in their image presentation. The purpose of this study was to compare four IVUS systems in vitro to determine the accuracy of tissue characterization of atherosclerotic plaque compared with histology. Ninety-eight plaque segments from 23 formalin-fixed human iliac arteries were imaged in saline at room temperature with four different IVUS systems. To assess the accuracy of IVUS in describing plaque, three types of analysis were performed: (1) the ability to identify the presence and extent of lumen or plaque boundary; (2) sensitivity, specificity, and interobserver variability of IVUS in qualitatively identifying plaque components compared with histology; and (3) quantification of calcification. The synthetic aperture device had a lower sensitivity in identifying lumen and plaque boundaries (87%, 38% respectively) compared with other machines (96%-100%, 95%-100%). All three mechanically rotating systems had fair to good sensitivities for identifying calcification (57%-73%) or lipid filled areas (50%-83%). The sensitivity of discriminating fibrous tissue from fatty areas was low (39%-52%). The synthetic aperture system had a significantly lower sensitivity for identifying all three tissue types (4%-21%). There was significant interobserver variability (kappa value = 0.47-0.68) as well as machine to machine variability (kappa value = 0.52) for tissue characterization. Calcified areas were underestimated by System 1 (p < .05) and System 4 (p < .01) because of weaker echo reflections or poor image quality. There are significant differences in image representation among these four IVUS systems in the diagnosis of tissue components of complex atherosclerotic plaque. These variabilities should be considered when interpreting studies performed with different machines.
不同的血管内超声（IVUS）系统在图像呈现方面存在差异。本研究的目的是在体外比较四种IVUS系统，以确定与组织学相比，动脉粥样硬化斑块组织特征的准确性。在室温下，使用四种不同的IVUS系统对来自23条福尔马林固定的人髂动脉的98个斑块节段在盐水中进行成像。为了评估IVUS描述斑块的准确性，进行了三种类型的分析：（1）识别管腔或斑块边界的存在和范围的能力；（2）与组织学相比，IVUS在定性识别斑块成分方面的敏感性、特异性和观察者间变异性；（3）钙化的量化。与其他机器（96%-100%，95%-100%）相比，合成孔径设备在识别管腔和斑块边界方面的敏感性较低（分别为87%，38%）。所有三种机械旋转系统在识别钙化（57%-73%）或脂质填充区域（50%-83%）方面具有中等至良好的敏感性。区分纤维组织和脂肪区域的敏感性较低（39%-52%）。合成孔径系统在识别所有三种组织类型方面的敏感性显著较低（4%-21%）。在组织特征描述方面，观察者间存在显著变异性（kappa值=0.47-0.68），机器间也存在变异性（kappa值=0.52）。由于回声反射较弱或图像质量较差，系统1（p<.05）和系统4（p<.01）低估了钙化区域。这四种IVUS系统在复杂动脉粥样硬化斑块组织成分的诊断中，图像表现存在显著差异。在解释使用不同机器进行的研究时，应考虑这些变异性。
