GEPARD – Vessel Wall Simulation and Visualization for Patient-Specific Blood Flow Prediction for Intracranial Aneurysm Modeling

颅内动脉瘤是人类脑血管的病理性扩张。它们可能导致破裂，导致死亡或不可逆转的残疾。因此，计算机辅助的数值方法被开发并应用于评估特定患者的破裂风险以及支持临床医生的治疗计划。目前，只对动脉瘤腔进行了评估。由于破裂往往依赖于颅内血管壁的炎症，目前的模拟和计算机支持的评估方法必须整合管壁。该项目促进了颅内血管壁信息和血管外结构的整合，从而可以提取有关破裂风险的临床信息。该项目追求三个目标：1)通过分割体外获得的光学相干断层扫描数据，提取患者特定的血管壁厚度，以模拟血流和脑动脉壁的流体-结构相互作用；2)区分单个血管壁层和特定的血管壁病理，进行力学测量，以制定材料定律，并实现复杂、交互的流体结构模拟可视化3)将血管外结构整合到血管周围区域的可视化和模拟中，用于计算机辅助评估动脉瘤的生长和运动上述子目标的实施，导致总的目标是支持医生制定患者-个体治疗计划。由此产生的系统允许现实和可靠的血流预测与特别适应的可视化技术。它为医疗用户提供了建议中定义的新提取的信息，从而显著改善了对颅内动脉瘤的评估。

Intracranial aneurysms are pathologic dilations of human brain vessels. They may cause a rupture leading to death or irreversible disabilities. Therefore, computer-assisted, numerical methods are developed and applied to assess the patient-specific rupture risk as well as to support the treatment planning of the clinician. At the moment, only the aneurysm lumen is evaluated. Since the rupture often depends on inflammations of the intracranial vessel wall, current simulation and computer-supported evaluation approaches have to integrate the wall. This project promotes the integration of intracranial vessel wall information and extravascular structures such that clinical information about the rupture risk can be extracted. The project pursues three objectives:1) Extraction of patient-specific vessel wall thicknesses via segmentation of ex-vivo acquired optical coherence tomography data for the fluid-structure interaction of simulated blood flow and cerebral artery wall2) Differentiation of individual vessel wall layers and specific vessel wall pathologies to conduct mechanical measurements to formulate material laws and to allow complex, interactive visualizations of fluid-structure simulations3) Integration of extravascular structures into the visualization and simulation of vessel-surrounding areas for the computer-assisted evaluation of aneurysm growth and movementThe implementation of the stated subgoals leads to the overall objective to support treating physicians in their patient-individual therapy planning. The resulting system allows for a realistic and reliable blood flow prediction with especially adapted visualization techniques. It provides the medical user with the newly extracted information defined in the proposal and thus considerably improves the evaluation of intracranial aneurysms.