Nicosia A, von Birgelen C, Serruys P W, Roelandt J R, Giuffrida G
Istituto di Cardiologia, Università degli Studi, Catania.
Cardiologia. 1997 Nov;42(11):1159-64.
The use of a new automated contour-detection system (CD) allows rapid quantification of the dimensions of coronary lumen and plaque in an entire three-dimensional set of intracoronary images (ICUS), obtained during an ECG-gated pull-back image acquisition. The aim of the study was to evaluate the reproducibility, feasibility and accuracy of this approach in the clinical setting. We examined 32 coronary stents implanted in 28 patients, mean age 59 +/- 16 years. The ICUS images were acquired during a motorized uniform-speed pull-back (0.5 mm/s) of the ultrasound catheter after angiographically guided stent optimization, recorded on videotape, and analyzed during a conventional two-dimensional ICUS examination. An ECG-gated pull-back was then performed and analyzed by a second operator using CD. The minimal lumen area and diameter of the stent and the lumen area of the reference segments were measured. Comparing the analysis on- and off-line, correlation coefficients (r) not less than 0.96, with a mean difference not higher than 0.3 +/- 1.5 were found. On the other side, the comparison between the two-dimensional analysis and the analysis performed on-line showed a good correlation between the two methods. The two-dimensional method revealed a systematic overestimation (delta = -1.3 +/- 2.3) of the area and diameter. The time required for the on-line three-dimensional analysis was 9 +/- 3 min, whereas the off-line analysis was performed within 35 +/- 10 min. Focal segments of stent underexpansion were seen in 4 cases by two-dimensional ICUS and in 3 more cases by three-dimensional ICUS, analyzed on- and off-line. In order to evaluate the reproducibility of the system, we examined ICUS images after an ECG-gated pull-back of 23 segments of coronary arteries in 20 patients. The intra and interobserver variability was evaluated. The mean relative difference between the area and volume measurements of intra and interobserver variability ranged from 0.14 to 1.51%, with a standard deviation not higher than +/- 7.17, a standard error of estimate not higher than +/- 4.85 and a correlation coefficient (r) not less than 0.98. Thus, the "contour detection" in ECG-gated three-dimensional ICUS is highly reproducible, suggesting the use of the system in studies of progression-regression of atherosclerosis. It is feasible for the on-line application as it can be performed rapidly and shows good agreement with measurements obtained by off-line CD.
使用一种新型自动轮廓检测系统（CD）能够快速量化在心电图门控回撤图像采集过程中获得的完整三维冠状动脉内图像（ICUS）中的冠状动脉管腔和斑块尺寸。本研究的目的是评估这种方法在临床环境中的可重复性、可行性和准确性。我们检查了28例患者体内植入的32个冠状动脉支架，患者平均年龄59±16岁。在血管造影引导下优化支架后，以匀速（0.5mm/s）机动回撤超声导管的过程中采集ICUS图像，记录在录像带上，并在传统二维ICUS检查期间进行分析。然后进行心电图门控回撤，并由第二名操作人员使用CD进行分析。测量支架的最小管腔面积和直径以及参考节段的管腔面积。比较在线和离线分析，发现相关系数（r）不小于0.96，平均差异不高于0.3±1.5。另一方面，二维分析与在线分析之间的比较显示两种方法之间具有良好的相关性。二维方法显示面积和直径存在系统性高估（δ=-1.3±2.3）。在线三维分析所需时间为9±3分钟，而离线分析在35±10分钟内完成。二维ICUS在4例中发现支架扩张不足的局灶节段，三维ICUS在线和离线分析又在另外3例中发现。为了评估该系统的可重复性，我们检查了20例患者23个冠状动脉节段心电图门控回撤后的ICUS图像。评估了观察者内和观察者间的变异性。观察者内和观察者间变异性的面积和体积测量的平均相对差异范围为0.14%至1.51%，标准差不高于±7.17，估计标准误差不高于±4.85，相关系数（r）不小于0.98。因此，心电图门控三维ICUS中的“轮廓检测”具有高度可重复性，表明该系统可用于动脉粥样硬化进展-消退的研究。它在线应用是可行的，因为它可以快速进行，并且与离线CD获得的测量结果显示出良好的一致性。
