Surgical planning for living donor liver transplant using 4D flow MRI, computational fluid dynamics and in vitro experiments

Abstract

This study used magnetic resonance imaging (MRI), computational fluid dynamics (CFD) modeling, and in vitro experiments to predict patient-specific alterations in hepatic hemodynamics in response to partial hepatectomy in living liver donors. 4D Flow MRI was performed on three donors before and after hepatectomy and models of the portal venous system were created. Virtual surgery was performed to simulate (1) surgical resection and (2) post-surgery vessel dilation. CFD simulations were conducted using in vivo flow data for boundary conditions. CFD results showed good agreement with in vivo data, and in vitro experimental values agreed well with imaging and simulation results. The post-surgery models predicted an increase in all measured hemodynamic parameters, and the dilated virtual surgery model predicted post-surgery conditions better than the model that only simulated resection. The methods used in this study have potential significant value for the surgical planning process for the liver and other vascular territories.

Assessment of vascular stiffness in the internal carotid artery proximal to the carotid canal in Alzheimer’s disease using pulse wave velocity from low rank reconstructed 4D flow MRI

“…4D flow provides accurate measures of flow values 24 with good agreement with flow probes 25 and measurement in model systems. 26 4D flow indices are also highly correlated with those from TCD, although those from MRI are underestimated by approximatively 30% 27 ; however, similar to with 2D, PWV measurements will require high temporal resolution to capture the pulse wave propagation along the arteries. Previous studies have estimated intracranial pulse wave transit time using 4D flow, finding significantly shorter transit times of the pulse wave from arteries to veins in AD subjects compared to cognitively healthy age-matched subjects.…”

Computational Modeling in Liver Surgery

“…Furthermore, in combination with a liver-specific contrast agent such as gadoxetic acid (Gd-EOB-DTPA), monitoring the perfusion dynamics and the uptake of the agent allows functional assessment of the liver (Imbriaco et al, 2017 ; Szklaruk et al, 2017 ; Zhou et al, 2017 ), thereby improving the detection of liver carcinoma and classification of microvascular invasion in hepatocellular carcinoma. Thus, MRI is a versatile modality for creating detailed, anatomically accurate models for computationally aided liver surgery (Oshiro and Ohkohchi, 2017 ; Rutkowski et al, 2017 ). In addition, it offers further potential in form of magnetic resonance cholangiography or contrast enhanced magnetic resonance angiography allowing comprehensive assessment of a patient's biliary and vascular status and possible complications (Boraschi et al, 2008 ).…”

“…A soft-tissue deformation model including hyperelasticity, porosity, and viscosity of hepatic tissue allows simulating realistic liver deformations and intrahepatic displacements in real time for surgery training (Marchesseau et al, 2010 ) and planning. Modern medical imaging coupled with computational fluid dynamics (CFD) modeling also facilitates predicting patient-specific alterations in hepatic hemodynamics in response to partial hepatectomy (Rutkowski et al, 2017 ).…”

Computational Fluid Dynamics and Additive Manufacturing to Diagnose and Treat Cardiovascular Disease

“…Such comparisons become untenable for complex geometries such as those found in the human vasculature. Some work has compared fluid simulation results with in vivo measurements from 4D-MRI [72, 73]; however, it is nearly impossible to control input parameters in a living biological system. 3D printed models offer a method to perform controlled fluid experiments for simulation validation.…”