In-silico heart model phantom to validate cardiac strain imaging

Area of Science:

• Cardiovascular Imaging and Mechanics
• Computational Biology
• Biomedical Engineering

Background:

• Quantifying cardiac strains is crucial for assessing cardiac function, but 4D motion heterogeneity complicates accurate regional strain measurement.
• Current methods show significant variability based on imaging modality and algorithms, hindering clinical translation of strain biomarkers.
• A reliable benchmark is needed to validate strain calculation algorithms for complex cardiac kinematics.

Purpose of the Study:

• To develop and validate an in-silico heart phantom using finite element (FE) simulations for accurate 4D regional strain quantification.
• To establish a feasible benchmark for assessing the reliability of strain calculation algorithms in cardiac mechanics.
• To investigate the impact of image quality on regional strain calculations.

Main Methods:

• Created synthetic magnetic resonance (MR) images from FE simulations of a hollow cylinder under torsion to validate twist angle recovery.
• Synthesized dynamic MR images from mouse-specific FE cardiac kinematics simulations of the left ventricle (LV).
• Calculated 4D regional strains using a novel non-rigid image registration (NRIR) framework and assessed image quality effects.

Main Results:

• Demonstrated accurate recovery of "ground-truth" twist angles in the torsion phantom, proving the concept.
• Successfully calculated 4D regional strains from synthesized dynamic MR images of the LV.
• Quantified the impact of varying image quality on regional strain calculations in different LV configurations.

Conclusions:

• The proposed in-silico heart phantom provides a rigorous and feasible tool for standardizing 4D regional strain calculations.
• This validation approach can enhance the reliability and clinical impact of strain measurements as biomarkers for cardiac dysfunction.
• The framework aids in understanding and mitigating image quality effects on strain quantification.