Modeling Hypoplastic Left Heart Syndrome Morphology for Statistical Shape and Biomechanics Analysis

Modeling the hearts of patient with hypoplastic left heart syndrome (HLHS) has remained an ongoing challenge due to its unique single ventricular morphology. Severe distortions have been observed when using generic biventricular shape templates to create three-dimensional models of HLHS anatomy, which can lead to inaccurate or unconverged numerical analysis. Thus, in this work, we developed a HLHS-specific biventricular template to capture single ventricle morphology in this cohort more accurately and robustly. We applied the HLHS-specific template to reconstruct HLHS patient-specific models from cardiac magnetic resonance images. Models created using the HLHS-specific template resulted in significantly higher accuracy compared with using the generic template to model the same cohort of patients. The models created using the cohort-specific template were also qualitatively more anatomically realistic with the size of left ventricle and relative location of the apex well captured. When patient-specific models are used for finite element analysis of biomechanics or electrophysiology, it is important to ensure that all elements in the mesh are within an acceptable level of distortion. Element distortion metrics, element edge angles and aspect ratios, confirmed that element distortion in meshes created using the HLHS-specific template is comparable with that of biventricular anatomic models previously used in finite element analysis. A semi-automated workflow, developed to use HLHS-specific template to create patient-individual models from manually segmented contours, will allow future users to create 3D models consistently and efficiently. Accurate 3D patient-specific models will serve as useful tools for statistical shape and physiological analysis to provide insights into new associations between ventricular morphology and clinical outcomes