Department of Biomedical Engineering, within the group of Biomedical Image Analysis, Eindhoven University of Technology.
IEEE Trans Vis Comput Graph. 2011 Dec;17(12):2153-62. doi: 10.1109/TVCG.2011.215.
Better understanding of hemodynamics conceivably leads to improved diagnosis and prognosis of cardiovascular diseases. Therefore, an elaborate analysis of the blood-flow in heart and thoracic arteries is essential. Contemporary MRI techniques enable acquisition of quantitative time-resolved flow information, resulting in 4D velocity fields that capture the blood-flow behavior. Visual exploration of these fields provides comprehensive insight into the unsteady blood-flow behavior, and precedes a quantitative analysis of additional blood-flow parameters. The complete inspection requires accurate segmentation of anatomical structures, encompassing a time-consuming and hard-to-automate process, especially for malformed morphologies. We present a way to avoid the laborious segmentation process in case of qualitative inspection, by introducing an interactive virtual probe. This probe is positioned semi-automatically within the blood-flow field, and serves as a navigational object for visual exploration. The difficult task of determining position and orientation along the view-direction is automated by a fitting approach, aligning the probe with the orientations of the velocity field. The aligned probe provides an interactive seeding basis for various flow visualization approaches. We demonstrate illustration-inspired particles, integral lines and integral surfaces, conveying distinct characteristics of the unsteady blood-flow. Lastly, we present the results of an evaluation with domain experts, valuing the practical use of our probe and flow visualization techniques.
更好地理解血液动力学可以提高心血管疾病的诊断和预后。因此，对心脏和胸部动脉中的血流进行详细分析是必不可少的。现代 MRI 技术能够获取定量的时变流信息，从而获得能够捕获血流行为的 4D 速度场。对这些场的可视化探索提供了对非稳定血流行为的全面了解，并为分析其他血流参数提供了基础。完整的检查需要准确地分割解剖结构，这包括一个耗时且难以自动化的过程，尤其是对于畸形形态。我们提出了一种在定性检查的情况下避免繁琐的分割过程的方法，即引入交互式虚拟探头。该探头半自动定位在血流场中，并作为视觉探索的导航对象。通过拟合方法自动完成沿视图方向确定位置和方向的困难任务，将探头与速度场的方向对齐。对齐后的探头为各种血流可视化方法提供了交互式的种子基础。我们展示了受启发于插图的粒子、积分线和积分面，它们传达了非稳定血流的独特特征。最后，我们呈现了与领域专家的评估结果，评估了我们的探头和血流可视化技术的实际用途。
