Cardiovascular 4D Flow MRI for multidirectional hemodynamic assessment: a single-centre observational study

To evaluate the feasibility and clinical utility of cardiovascular four-dimensional flow magnetic resonance imaging (4D Flow MRI) for multidirectional hemodynamic visualization and quantitative assessment.

This single-centre observational study included 30 cardiovascular MRI cases acquired at Huaqiao University Affiliated Strait Hospital using a Siemens MAGNETOM Skyra 3.0-T system with an 18-channel phased-array coil. Time-resolved three-dimensional velocity-encoded 4D Flow MRI was performed with retrospective electrocardiographic gating, respiratory compensation, and region-adjusted velocity encoding. Acquisition parameters included TR/TE 38.88/6.88 ms, flip angle 8°, matrix 256 × 256, field of view 300 mm, in-plane spatial resolution 1.4 × 1.4 mm, slice thickness 3 mm, and slice gap 0.6 mm. Preprocessing corrected background phase offsets, Maxwell terms, velocity aliasing, and noise artefacts.

4D Flow MRI enabled assessment of intracardiac shunting, pulmonary regurgitation, Fontan circulation, bicuspid aortic valve hemodynamics, aortic regurgitation, and atrioventricular valve dysfunction. Quantified parameters included pulmonary-to-systemic flow ratio, shunt volume, regurgitant fraction, peak velocity, pressure gradient, wall shear stress, vorticity, helicity, kinetic energy, turbulent kinetic energy, oscillatory shear index, and energy loss.

Cardiovascular 4D Flow MRI supports patient-specific hemodynamic assessment across complex cardiovascular conditions within a practical single-centre clinical workflow with retrospective quantification.