心肌及心血管系统的四维可视化技术研究与实现

Design and implementation of four-dimensional visualization technology for myocardium and cardiovascular system

目的为克服二维医学图像和三维重建无法实时、多方位和多角度观察心脏运动形态的不足,提出一种全新的四维可视化解决方案来实现心肌及心血管系统的动态显示。方法以三维实时显示技术为基础,编程实现序列体数据的读入、显示和管理,将心脏运动模型离散化,使序列体数据显示的时间间隔与真实的心动周期时间间隔保持一致,实时显示心脏离散化序列体数据,实现心肌四维可视化;通过改变不同部位的透明度来实现心血管系统的四维可视化。结果该四维可视化技术主要有两大优点:①采用心脏CT图像重建得到心脏体数据模型,效果逼真;②采用异步纹理绘制技术动态、四维显示心血管系统,避免了延时现象,使得心血管系统四维可视化更加真实、流畅。结论心肌及心血管系统的四维可视化技术可多方位、多角度显示心脏的实时搏动。

Objective To put forward a new four-dimensional visualization solution for achievement of displaying myocardium and cardiovascular system with four-dimensional （4D） technology, in order to overcome the shortcomings of two-dimensional medical images and three-dimensional reconstruction images, which could not real-timely, all-roundly and multi-angle display cardiac motion morphology. Methods Based on real time 3D display technology, sequence volume data were read, displayed and managed by programming. Then the cardiac motion model was discretized to make the interval of displaying the sequence of volume images keep pace with that of the cardiac cycle. In a result, discretized sequence volume data of myocardium were displayed real-timely, and finally 4D visualization of heart was realized. In addition, the 4D visualization of cardiovascular system could also be realized by changing the transparency of different parts. Results This 4D visualization technology had two main advantages. Firstly, heart volume data model was reconstructed using cardiac CT image, so volume data were lifelike. Secondly, 4D dynamic displaying of cardiovascular structures was realized using asynchronous texture rendering method in order to avoid delay and visualize cardiovascular structures even more realistically and smoothly. Conclusion This technique provided a method to display images visually and vividly for observing cardiac pulsating from any azimuth and angle in real time.