Dhawale P J, Wilson D L, Hodgson J M
Division of Cardiology, University Hospitals of Cleveland, OH 44106.
Cathet Cardiovasc Diagn. 1994 Jul;32(3):288-99. doi: 10.1002/ccd.1810320321.
Three-dimensional analysis using intracoronary ultrasound (ICUS) pull-back data provides the unique ability to quantitate lumen and atherosclerotic plaque volumes. Optimal data acquisition parameters for volumetric acquisition were established using simulations on computer phantoms of stenotic arteries. Eleven computer phantoms were generated using cross-sectional area data from quantitative angiography of stenotic coronary arteries. Three methods of data acquisition were simulated: conventional manual pull-back; motorized pull-back; and manual pull-back with measured displacement. Effects of pull-back velocity and cardiac gating on cross-sectional area profiles and volumes were studied. Cardiac gating eliminated errors introduced by vessel deformation within a cardiac cycle. With cardiac gating, pull-backs with mean velocities up to 1.2 mm/sec allowed reconstruction of cross-sectional area profiles within 5% RMS error. With faster pull-backs, cardiac gating resulted in sparse spatial sampling and significant errors in cross-sectional area profiles. The accuracy of both motorized and measured required equal displacements of the catheter proximal and distal ends. This assumption was validated with in vitro experiments where X-ray fluoroscopy was used to measure the displacement of the imaging tip. Excellent correlation was found between the two displacements (r = 0.99). Finally, slow pull-backs were performed by 3 operators, and pull-back velocities were measured. It was found that mean pull-back velocities as low as 0.8 mm/sec were achievable. From our simulations, we predict that accurate volumetric analysis requires cardiac gated, calibrated, slow (< 1.2 mm/sec) pull-backs.
使用冠状动脉内超声（ICUS）回撤数据进行三维分析，能够独特地定量管腔和动脉粥样硬化斑块体积。通过对狭窄动脉的计算机模型进行模拟，确定了用于容积采集的最佳数据采集参数。利用狭窄冠状动脉定量血管造影的横截面积数据生成了11个计算机模型。模拟了三种数据采集方法：传统手动回撤；电动回撤；以及带测量位移的手动回撤。研究了回撤速度和心脏门控对横截面积轮廓和体积的影响。心脏门控消除了心动周期内血管变形引入的误差。采用心脏门控时，平均速度高达1.2毫米/秒的回撤能够重建均方根误差在5%以内的横截面积轮廓。回撤速度更快时，心脏门控会导致空间采样稀疏以及横截面积轮廓出现显著误差。电动回撤和带测量位移回撤的准确性都要求导管近端和远端有相等的位移。这一假设在体外实验中得到了验证，实验中使用X射线荧光透视法测量成像尖端的位移。发现两种位移之间具有极佳的相关性（r = 0.99）。最后，由3名操作人员进行缓慢回撤，并测量回撤速度。发现平均回撤速度低至0.8毫米/秒是可以实现的。根据我们的模拟，我们预测准确的容积分析需要心脏门控、校准、缓慢（<1.2毫米/秒）的回撤。
