Analysis of cavopulmonary and cardiac flow characteristics in fontan Patients: Comparison with healthy volunteers

BACKGROUND: Characterizing the flow characteristics of the Fontan circuit, and correlating these characteristics with the development of complications, is an important clinical challenge. Past work has analyzed the flow characteristics of Fontan circulation on a component-by-component basis. Four-dimensional (4D) flow magnetic resonance imaging (MRI) with radial projections allows for large volumetric coverage, and therefore can be used to analyze the flow through many co-dependent cardiovascular components in a single imaging session. PURPOSE: The purpose of this study is to describe flow characteristics across the entire Fontan circuit and to compare these with the flow characteristics in healthy volunteers. STUDY TYPE: Prospective SUBJECTS: Eleven (11) single ventricle patients with a Fontan connection and fifteen (15) healthy controls. SEQUENCE: Phase Contrast with Vastly undersampled Isotropic Projection Reconstruction (PC-VIPR) at a field strength of 3T. ASSESSMENT: Cavopulmonary and ventricular flow distributions, blood flow kinetic energy, vorticities, efficiency indices, and other flow parameters were analyzed using Ensight and Matlab. STATISTICAL TESTS: Results were compared across Fontan subjects, between respiratory phases, and between Fontan subjects and healthy volunteers using a Student’s t-test for unequal sample sizes and linear regression. RESULTS: Cava-specific pulmonary flow distributions of Fontan patients varied significantly between respiratory phases (p