Abstract：
Accurate assessment of portacaval pressure gradient (PCG) in patients with portal hypertension (PH) is of great significance both for diagnosis and treatment. This study aims to develop a noninvasive method for assessing PCG in PH patients and evaluate its accuracy and effectiveness. This study recruited 37 PH patients treated with transjugular intrahepatic portosystemic shunt (TIPS). computed tomography angiography was used to create three dimension (3D) models of each patient before and after TIPS. Doppler ultrasound examinations were conducted to obtain the patient\'s portal vein flow (or splenic vein and superior mesenteric vein). Using computational fluid dynamics (CFD) simulation, the patient\'s pre-TIPS and post-TIPS PCG was determined by the 3D models and ultrasound measurements. The accuracy of these noninvasive results was then compared to clinical invasive measurements. The results showed a strong linear correlation between the PCG simulated by CFD and the clinical invasive measurements both before and after TIPS (R2 = 0.998, P < 0.001 and R2 = 0.959, P < 0.001). The evaluation accuracy of this noninvasive method reached 94 %, and the influence of ultrasound result errors on the numerical accuracy was found to be marginal if the error was less than 20 %. Furthermore, the information about the hemodynamic environment in the portal system was obtained by this numerical method. Spiral flow patterns were observed in the portal vein of some patients. In a conclusion, this study proposes a noninvasive numerical method for assessing PCG in PH patients before and after TIPS. This method can assist doctors in accurately diagnosing patients and selecting appropriate treatment plans. Additionally, it can be used to further investigate potential biomechanical causes of complications related to TIPS in the future.
摘要：
准确评估门静脉高压症(PH)患者的门腔压力梯度(PCG)对诊断和治疗具有重要意义。本研究旨在开发一种评估PH患者PCG的非侵入性方法，并评估其准确性和有效性。这项研究招募了37例经颈静脉肝内门体分流术（TIPS）治疗的PH患者。在TIPS前后,我们使用计算机断层扫描血管造影创建每位患者的三维(3D)模型.进行多普勒超声检查以获取患者的门静脉血流（或脾静脉和肠系膜上静脉）。使用计算流体动力学(CFD)模拟,通过3D模型和超声测量确定患者的TIPS前和TIPS后PCG。然后将这些非侵入性结果的准确性与临床侵入性测量进行比较。结果表明，CFD模拟的PCG与TIPS前后的临床侵入性测量之间存在很强的线性相关性（R2=0.998，P<0.001，R2=0.959，P<0.001）。这种无创方法的评价准确率达到94%,如果误差小于20％，则超声结果误差对数值精度的影响很小。此外，通过这种数值方法获得了有关入口系统中血液动力学环境的信息。在一些患者的门静脉中观察到螺旋流型。在一个结论中，这项研究提出了一种非侵入性数值方法来评估PH患者TIPS前后的PCG。该方法可以帮助医生准确诊断患者并选择合适的治疗方案。此外,未来可用于进一步研究与TIPS相关的并发症的潜在生物力学原因.
