Evaluation of Regurgitation Fraction in Repaired Tetralogy of Fallot Using 2D-PC and 4D Flow MRI

Motivation: Severe pulmonary regurgitation in repaired Tetralogy of Fallot (TOF) patients requires accurate assessment of regurgitation fraction (RF) for effective management. Goal(s): To evaluate RF by measuring Forward Flow Volume (FFV) and Backward Flow Volume (BFV) with both 2D-PC and 4D Flow MRI, and to identify optimal measurement locations. Approach: Thirty TOF patients underwent 2D-PC and 4D Flow MRI. FFV and BFV were measured at consistent and multiple cross-sections, analyzing the effects of artery shape and turbulence. Results: 2D-PC and 4D Flow showed high correlation, but artery dilation and turbulence impacted 4D Flow values. Near-valve, minimally dilated regions provided more consistent RF measurements. Impact: This study enhances the reliability of 4D Flow MRI for RF measurement in TOF patients by comparing it to 2D-PC. 4D Flow assessment helps explore optimal measurement sites, leading to more accurate evaluations and better management of pulmonary regurgitation.