Solzbach U, Oser U, Rombach M, Wollschläger H, Just H
University of Freiburg, Department of Cardiology, Germany.
Comput Biomed Res. 1994 Jun;27(3):178-98. doi: 10.1006/cbmr.1994.1016.
Using a biplane multidirectional isocentric X-ray system, a computer-aided simulation procedure was developed to calculate the 3D structure of the coronary arteries. The algorithm uses the geometry of the biplane X-ray system and the alignments of corresponding points of the coronary arteries in two X-ray images acquired under different viewing angles. The identification of the corresponding points is greatly simplified by the calculation and display of the intersection lines of the confocal plane with the image intensifier entrances on the computer monitor. To minimize the total number of necessary corresponding points we used Bézier curves to match the courses of the coronary segments between neighboring corresponding points. The projection of the calculated 3D structure was found to be in very good agreement with the 2D course of the coronary arteries in the angiograms. The 3D structure can be viewed on the computer screen under any desired simulated projection angle within the geometrical limitation of the X-ray gantries. The user can select views on the computer monitor with orthogonal projection angles and minimal overlapping problems caused by under- and overlying structures. The method was applied in 10 cases of elective angioplasty. Previously taken diagnostic angiograms were used to reconstruct the arterial structure and to select favorable views for the forthcoming intervention.
利用双平面多向等中心X射线系统，开发了一种计算机辅助模拟程序来计算冠状动脉的三维结构。该算法利用双平面X射线系统的几何结构以及在不同视角下获取的两幅X射线图像中冠状动脉对应点的对齐情况。通过在计算机显示器上计算和显示共焦平面与图像增强器入口的交线，大大简化了对应点的识别。为了尽量减少所需对应点的总数，我们使用贝塞尔曲线来匹配相邻对应点之间冠状动脉段的走向。发现计算出的三维结构投影与血管造影中冠状动脉的二维走向非常吻合。在X射线龙门架的几何限制范围内，可以在计算机屏幕上以任何所需的模拟投影角度查看三维结构。用户可以在计算机显示器上选择具有正交投影角度且由下层和上层结构引起的重叠问题最小的视图。该方法应用于10例择期血管成形术。以前拍摄的诊断性血管造影用于重建动脉结构，并为即将进行的干预选择有利的视图。
