Three-Dimensional Time-resolved Cardiovascular Magnetic Resonance Imaging based Particle Tracing: Recommendations: Effects of integration method, integration timestep and interpolation method on particle tracing outcomes

IntroductionCardiovascular magnetic resonance imaging (CMR) is an imaging modality from which the structure, function, perfusion, and metabolism of the cardiovascular system can be evaluated, which is essential in acquired and congenital cardiovascular disease (CVD). CMR can improve the outcomes of CVD during long term follow-up. 4D Flow MRI is a three-dimensional time-resolved CMR technique that uses phase contrast sequences with three-directional velocity-encoding and allows evaluation of the blood flow. 4D Flow MRI data can be analyzed with particle tracing.Particle tracing is a technique that releases virtual particles in flow data (seeding) and traces the path the particles follow throughout the vasculature by integrating the flow data. The particle traces can subsequently be quantified with flow distribution analyses and visualized with pathlines. Important settings for particle tracing are the integration method, integration timestep and data interpolation method. The aim of this research is to investigate the effect of different particle tracing settings on the accuracy and computation time and provide a recommendation on the use of particle tracing in 4D Flow MRI data and which particle tracing settings to aim for.MethodsA particle tracing algorithm with a graphical user interface was developed for an existing inhouse developed 4D Flow post-processing workspace. Two 4D Flow MRI datasets from previous studies were acquired. One dataset was of a total cavopulmonary connection of a patient with Fontan circulation and the other was an intracardiac dataset of a healthy volunteer. Particle tracing with common settings and variations in integration method, integration timestep and data interpolation method was performed in both datasets and computation time, flow distributions (pulmonic distribution and four-component analysis), and number of particles that left the structure (missing particles fraction) and number of integration errors were quantified. The latter
Mechanical Engineering | BioMechanical Design