3D MRI-Based Modeling for Computer-Aided Right Ventricle Remodeling Surgery

描述（由申请人提供）：先天性心脏手术后晚期发生的右心室功能障碍是先天性心脏病成人心力衰竭的最常见原因之一。在法洛四联症（ToF）中，最常见的紫绀型心脏缺陷，婴儿期的初始修复涉及RV流出道（包括肺动脉瓣）的切口和补片，这通常会导致由于慢性肺动脉返流和RV瘢痕/补片扩张导致的重度RV扩张和功能障碍的晚期发展。目前晚期RV功能障碍的外科治疗包括肺动脉瓣插入和RV流出道补片减少，可减少RV容积，但不会导致RV功能的可预测改善。一项更激进的手术，包括广泛切除疤痕和流出道补片，正在NHLBI赞助的随机前瞻性试验中进行评估。然而，目前还没有可用的方法来预测任何一种手术后的结果或对于给定患者的最佳手术是什么，即没有用于确定患者特异性治疗的临床上有用的工具。在本项目中，我们建议开发一种计算建模方法，以确定各种重建方案治疗ToF患者失败RV的有效性和适用性。我们将使用非侵入性心脏磁共振成像（CMR）来提供患者特定的RV/LV形态、变形和血流数据，用于构建和验证计算模型。将构建基于CMR的RV/LV组合三维模型，其中包括流体-结构相互作用（RV/LV和RV补片）、双层RV/LV结构、各向异性材料特性、纤维取向和主动收缩，以模拟血流、心脏运动和应力/应变分布，从而评价不同重塑程序对RV功能的影响，并寻求最佳的RV体积和补片设计以改善术后RV功能。来自正在进行的NHLBI资助的临床试验的临床成像和血流动力学数据将用于构建和验证模型。我们的最终目标是将这种方法应用于患者特定的计算机辅助心脏手术计划，以达到先天性心脏病RV功能障碍患者的最佳手术设计和结局。一个由先天性心脏手术、心脏病学和计算数学方面经验丰富的多学科研究人员组成的小组将开展这一项目。公共卫生相关性：本项目旨在使用从正在接受手术评估的法洛四联症修复患者获得的MRI图像来开发右心室功能的计算模型。最终目标是开发模型，预测手术后的结果并优化右心室功能。用于本研究的MRI是临床适应症研究，作为这些患者护理的一部分，目前根据批准的方案获得，其中Tal Geva博士是主要研究者。

DESCRIPTION (provided by applicant): Right ventricular dysfunction developing late after congenital cardiac surgery is one of the most common causes of heart failure in adults with congenital heart disease. In tetra logy of Fallot (ToF), the most common cyanotic heart defect, initial repair in infancy involves an incision and patch in the RV outflow, including the pulmonary valve, which often results in late development of severe RV dilatation and dysfunction due to chronic pulmonary regurgitation and RV scarring/patch dilatation. Current surgical management of late RV dysfunction, consisting of pulmonary valve insertion and reduction of the RV outflow patch, reduces RV volume but does not result in a predictable improvement in RV function. A more radical procedure, which includes extensive removal of scar and outflow patch, is being evaluated in an NHLBI sponsored randomized prospective trial. However, there is no currently available method for predicting outcome after either procedure or what the optimal procedure is for a given pt., i.e. no clinically useful tools for determining patient-specific therapy. In this project, we propose to develop a computational modeling approach to determine the efficacy and suitability of the various reconstructive options to treat failing RV in ToF pts. We will use non-invasive cardiac magnetic resonance imaging (CMR) to provide patient-specific RV/LV morphology, deformation, and flow data for the construction and validation of computational models. 3D CMR-based RV/LV combination models will be constructed, which include fluid-structure interactions (RV/LV and RV patch), two-layer RV/LV structure, anisotropic material properties, fiber orientation, and active contraction to simulate blood flow, heart motion, and stress/strain distribution to evaluate the effect of different remodeling procedures on RV function, and to seek an optimal RV volume and patch design to improve post-operative RV function. Clinical imaging and hemodynamic data from an ongoing NHLBI-funded clinical trial will be used to build and validate the model. Our ultimate goal is to apply this methodology in patient- specific computer-aided cardiac surgery planning to reach optimal surgical procedure design and outcome in patients with RV dysfunction from congenital heart defects. A multidisciplinary group of experienced investigators in congenital cardiac surgery, cardiology and computational mathematics will conduct this project. PUBLIC HEALTH RELEVANCE: This project aims to use MRI images obtained from patients with repair tetralogy of Fallot that are being evaluated for surgery to develop computational models of right ventricular function. The ultimate goal is to develop models that will predict outcomes and optimize right ventricular function after surgery. The MRI's to be used for this study are clinically indicated studies as part of the care of these patients and are currently obtained under an approved protocol where Dr. Tal Geva is the principal investigator.