4D flow MRI enhances prototype testing of a total artificial heart

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Donor heart shortages necessitate advanced Total Artificial Hearts (TAHs).
• Existing TAHs face complications from suboptimal blood flow dynamics.
• Assessing TAH flow dynamics is technically challenging.

Purpose of the Study:

• To evaluate 4D flow MRI for assessing blood flow in a pulsatile TAH.
• To investigate the feasibility of using 3D printing for MRI-compatible TAH prototypes.
• To analyze flow patterns and energy loss in a TAH under various physiological conditions.

Main Methods:

• A prototype pulsatile TAH was modified using 3D printing (powder bed fusion and fused filament fabrication) for MRI compatibility.
• The TAH was integrated into an MRI-compatible mock circulatory loop, allowing testing at 80, 105, and 120 bpm.
• 4D flow MRI with dual velocity encoding was employed to capture detailed flow dynamics and turbulent kinetic energy.

Main Results:

• 4D flow MRI accurately measured flow patterns and turbulent kinetic energy in the TAH.
• Stasis and viscous energy loss were comparable to healthy native hearts.
• Elevated turbulent kinetic energy was observed but remained below levels seen in valvular disease patients.

Conclusions:

• 4D flow MRI is a feasible tool for assessing TAH hemodynamics.
• Combining 4D flow MRI with 3D printing enables rapid TAH design iteration.
• This approach can help mitigate TAH-related complications by optimizing flow dynamics.