Feature Detection to Segment Cardiomyocyte Nuclei for Investigating Cardiac Contractility

Abstract

In vivo quantitative assessment of structural and functional biomarkers is essential for understanding pathophysiology and identifying novel therapies for congenital heart disorders. Cardiac defect analysis through fixed tissue and histology has offered revolutionary insights into the tissue architecture, but section thickness limits the tissue penetration. This study demonstrated the potential of Light Sheet Fluorescence Microscopy (LSFM) for analyzing in vivo 4D (3d + time) cardiac contractility. Furthermore, we have described the utility of an improved feature detection framework for localizing cardiomyocyte nuclei in the zebrafish atrium and ventricle. Using the Hessian Difference of Gaussian (HDoG) scale space in conjunction with the watershed algorithm, we were able to quantify a statistically significant increase in cardiomyocyte nuclei count across different developmental stages. Furthermore, we assessed individual volumes and surface areas for the cardiomyocyte nuclei in the ventricle's innermost and outermost curvature during cardiac systole and diastole. Using the segmented nuclei volumes from the feature detection, we successfully performed local area ratio analysis to quantify the degree of deformation suffered by the outermost ventricular region compared to the innermost ventricular region. This paper focuses on the merits of our segmentation and demonstrates its efficacy for cell counting and morphology analysis in the presence of anisotropic illumination across the field-of-view (FOV).

Automated identification of cardiomyocyte nuclei in H and E-stained heart tissue with CycleGAN

“…While there are many existing approaches to identify cell nuclei, few focus on H&E-stained tissue, and even fewer still mention cardiomyocyte nuclei. Many of these methods focus instead on the use of immunostaining and fluorescence microscopy to facilitate the identification process [5,6].…”

Scale space detector for analyzing spatiotemporal ventricular contractility and nuclear morphogenesis in zebrafish

“…However, acquisition of dynamic organogenesis reported by endogenous fluorophores is a challenging task owing to anisotropic contrast across the field of view (FOV). This is due to photon propagation through heterogeneous tissue (Teranikar et al, 2020(Teranikar et al, , 2021. Hence, precise orchestration of in vivo volumes requires high sensitivity with respect to dynamic tissue motion and differing scales.…”