Full-volume three-component intraventricular vector flow mapping by triplane color Doppler.

Area of Science:

• Cardiovascular Imaging
• Fluid Dynamics
• Biomedical Engineering

Background:

• Intraventricular vector flow mapping (iVFM) is a 2D technique for assessing left ventricular blood flow.
• Conventional iVFM is compatible with clinical settings due to its basis in color Doppler imaging.
• Generalizing iVFM to three dimensions (3D-iVFM) is crucial for comprehensive hemodynamic analysis.

Purpose of the Study:

• To generalize the intraventricular vector flow mapping (iVFM) technique for three-dimensional reconstruction (3D-iVFM).
• To recover three-component velocity vector fields in the full intraventricular volume using clinical echocardiographic triplane mode.
• To validate the accuracy and clinical feasibility of 3D-iVFM for assessing left ventricular hemodynamics.

Main Methods:

• 3D-iVFM was formulated in a spherical coordinate system adapted to the six half-planes of the triplane echocardiographic mode.
• The method utilized mass conservation and free-slip boundary conditions on the endocardial wall.
• Least-squares minimization with Lagrange multipliers was employed, validated using patient-specific computational fluid dynamics (CFD) models and in vivo patient data.

Main Results:

• Satisfactory recovery of radial (r=0.99) and polar (r=0.78) velocity components in CFD simulations.
• Azimuthal components showed larger errors (r=0.57) due to limited sampling.
• 3D-iVFM successfully deciphered intraventricular vortex dynamics during diastole in both in silico and in vivo studies, with accurate estimation of mean vorticity in CFD.

Conclusions:

• 3D-iVFM demonstrates the potential to provide full-volume echocardiographic information on left intraventricular hemodynamics.
• The technique leverages the clinical triplane color Doppler modality for enhanced hemodynamic assessment.
• This advancement offers a promising tool for detailed analysis of blood flow within the left ventricle.