Title: Non-invasive Assessment of Hepatic Venous Pressure Gradient (HVPG) Based on MR Flow Imaging and Computational Fluid Dynamics Show Chinese title

Title: 基于磁共振血流成像和计算流体力学的肝静脉压力梯度（HVPG）无创评估

Abstract: Clinically significant portal hypertension (CSPH) is a severe complication of chronic liver disease associated with cirrhosis, which is diagnosed by the measurement of hepatic venous pressure gradient (HVPG). However, HVPG measurement is invasive and therefore difficult to be widely applied in clinical routines. There is no currently available technique to measure HVPG noninvasively. Computational fluid dynamics (CFD) has been used for noninvasive measurement of vascular pressure gradient in the intracranial and coronary arteries. However, it has been scarcely employed in the hepatic vessel system due to the difficulties in reconstructing precise vascular anatomies and setting appropriate boundary conditions. Several computer tomography and ultrasound based studies have verified the effectiveness of virtual HVPG (vHVPG) by directly connecting the portal veins and hepatic veins before CFD simulations. We apply the latest techniques of phase-contrast magnetic resonance imaging (PC-MRI) and DIXON to obtain the velocity and vessel anatomies at the same time. Besides, we improve the CFD pipeline in regards to the construction of vessel connections and reduction of calculation time. The proposed method shows high accuracy in the CSPH diagnosis in a study containing ten healthy volunteers and five patients. The MRI-based noninvasive HVPG measurement is promising in the clinical application of CSPH diagnosis. Show Chinese abstract

Abstract: 临床上显著的门脉高压（CSPH）是与肝硬化相关的慢性肝病的严重并发症，通过测量肝静脉压力梯度（HVPG）来诊断。 然而，HVPG测量是侵入性的，因此难以在临床常规中广泛使用。 目前尚无可用的技术可以非侵入性地测量HVPG。 计算流体动力学（CFD）已被用于颅内和冠状动脉血管压力梯度的非侵入性测量。 然而，由于重建精确的血管解剖结构和设置适当的边界条件的困难，它在肝血管系统中的应用很少。 几项基于计算机断层扫描和超声的研究通过在CFD模拟前直接连接门静脉和肝静脉验证了虚拟HVPG（vHVPG）的有效性。 我们应用了最新的相位对比磁共振成像（PC-MRI）和DIXON技术同时获取速度和血管解剖结构。 此外，我们在血管连接构建和计算时间减少方面改进了CFD流程。 所提出的方法在包含十名健康志愿者和五名患者的的研究中显示出在CSPH诊断中的高准确性。 基于MRI的非侵入性HVPG测量在CSPH诊断的临床应用中具有前景。