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

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Hemodynamics

Background:

• Cardiovascular diseases require accurate hemodynamic assessment.
• Multidirectional flow visualization is crucial for understanding complex cardiac conditions.
• Current imaging techniques may have limitations in comprehensive hemodynamic evaluation.

Purpose of the Study:

• To evaluate the feasibility of cardiovascular four-dimensional flow MRI (4D Flow MRI).
• To assess the clinical utility of 4D Flow MRI for multidirectional hemodynamic visualization.
• To determine the quantitative assessment capabilities of 4D Flow MRI in cardiovascular applications.

Main Methods:

• A single-centre observational study involving 30 cardiovascular MRI cases.
• Utilized a Siemens MAGNETOM Skyra 3.0-T system with a 3D velocity-encoded 4D Flow MRI sequence.
• Employed retrospective ECG gating, respiratory compensation, and region-adjusted velocity encoding with specific acquisition parameters and preprocessing steps.

Main Results:

• 4D Flow MRI successfully assessed intracardiac shunting, pulmonary regurgitation, Fontan circulation, bicuspid aortic valve hemodynamics, aortic regurgitation, and atrioventricular valve dysfunction.
• Quantified various hemodynamic parameters including flow ratios, shunt volumes, regurgitant fractions, peak velocities, pressure gradients, wall shear stress, vorticity, helicity, kinetic energy, turbulent kinetic energy, oscillatory shear index, and energy loss.
• Demonstrated the ability to visualize and quantify complex flow patterns.

Conclusions:

• Cardiovascular 4D Flow MRI is a feasible technique for patient-specific hemodynamic assessment.
• The method supports clinical workflows for complex cardiovascular conditions.
• Retrospective quantification of hemodynamic parameters is achievable with 4D Flow MRI.