Euclidean and Shape-Based Analysis of the Dynamic Mitral Annulus in Children using a Novel Open-Source Framework

Area of Science:

• Cardiovascular Research
• Pediatric Cardiology
• Medical Imaging Analysis

Background:

• The dynamic shape of the adult mitral annulus is vital for mitral valve function.
• Pediatric mitral annular dynamics in healthy children remain under-explored.
• Understanding these dynamics is essential for pediatric cardiovascular health.

Purpose of the Study:

• To model and quantify the shape and variation modes of pediatric mitral valve annuli.
• To analyze annular dynamics across four cardiac phases in children.
• To establish a baseline for pediatric mitral annulus morphology.

Main Methods:

• Utilized 3D echocardiography and the SlicerHeart extension for mitral annulus modeling in 100 children.
• Quantified annular metrics and explored body surface area normalization.
• Computed mean shapes and principal components of variation using custom analysis modules.

Main Results:

• The mitral valve's "saddle shape" (height-to-width ratio) showed significant age-related changes in systole (P < .001).
• Annular metrics varied significantly between diastolic and systolic phases.
• Principal-component analysis identified size, height-to-width ratio, and sphericity as primary variation modes.

Conclusions:

• The pediatric mitral annulus maintains its saddle shape across childhood, with significant cardiac cycle variations.
• Major modes of pediatric mitral annulus variation include size, height-to-width ratio, and sphericity.
• Age- and size-specific models can guide the development of pediatric mitral annuloplasty rings.