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

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