Spectral Bias Correction in PINNs for Myocardial Image Registration of Pathological Data
Bastien C. Baluyot, Marta Varela, Chen Qin
TL;DR
This work tackles spectral bias in physics-informed neural networks (PINNs) for myocardial image registration, where high-frequency deformation details are critical for accurate biomechanical analysis in cardiomyopathies. It combines WarpPINN with Fourier Feature mappings and introduces modulation strategies based on sinusoidal representations (SIRENs) to better capture localized, high-frequency deformations while preserving myocardial incompressibility. The approach is evaluated on CMAC and ACDC datasets, showing superior registration accuracy (lower mean contour distance) and robust volume preservation, along with improvements in landmark tracking when applicable. The findings suggest that Fourier Feature encoding and SIREN-based modulation provide a scalable path toward generalizable PINN-based registration across diverse patients and cardiac pathologies, with implications for improved cardiac motion analysis and disease assessment.
Abstract
Accurate myocardial image registration is essential for cardiac strain analysis and disease diagnosis. However, spectral bias in neural networks impedes modeling high-frequency deformations, producing inaccurate, biomechanically implausible results, particularly in pathological data. This paper addresses spectral bias in physics-informed neural networks (PINNs) by integrating Fourier Feature mappings and introducing modulation strategies into a PINN framework. Experiments on two distinct datasets demonstrate that the proposed methods enhance the PINN's ability to capture complex, high-frequency deformations in cardiomyopathies, achieving superior registration accuracy while maintaining biomechanical plausibility - thus providing a foundation for scalable cardiac image registration and generalization across multiple patients and pathologies.
