Initial demonstration of free-running whole-heart radial 4D flow using ultra-short echo times (UTE)

Motivation: Free-running phase-contrast whole-heart MRI, despite its ease of use and efficiency may suffer from artifacts and inaccuracy in the presence of non-laminar flow and high velocities due to prolonged echo times. Goal(s): Our goal was to reduce the echo time in free-running radial 4D flow (radial 4D flow). Approach: We incorporated ultra-short echo time (UTE) imaging techniques into our radial 4D flow framework. Results: Net flow and peak flow measurements that correlate well with reference values were obtained in a cohort of healthy volunteers with the modified sequence and enabled qualitative evaluation of turbulent flow in patients with congenital heart disease. Impact: The combination of UTE and radial 4D flow MRI marks a step towards a more precise and robust quantification of hemodynamics under complex conditions, in an effort to improve both diagnosis and patient outcomes.