Ellipsoid fitting for movement tracking and HIFU lesion simulation on mobile organs

Elodie Constanciel , Jean-Martial Mari (1) , Samuel Pichardo , Francoise Chavrier (2) , Cyril Lafon (1)

1 LabTAU - Application des ultrasons à la thérapie
2 Applications des ultrasons à la thérapie

Atrial fibrillation is the most frequent cause of cardiac arrhythmia. In order to treat it in a minimally invasive way, a transesophageal HIFU system is being designed. To predict the shape of the HIFU lesion and design the heating procedure, simulations must be performed on a beating heart model. The complex movements of the left atrium make the displacement estimation difficult. However a simple model fitting, here an ellipsoid, could allow estimating with a reasonable accuracy the tissue movement. A fitting algorithm has been designed and is tested on numerical phantoms of ovoid shape. Fitting ellipsoids at multiple times allows matching their surfaces, deriving the movement and extrapolating to the entire volume. Lesion size with and without movement are then simulated using the Rayleigh model and the Bio Heat Transfer Equation, and compared. Future work will apply this fitting on real atrium data extracted from 4D CT sequences.

Mots clés: Model fitting; movement tracking; HIFU lesions; Simulations

Domaines: Acoustique [physics.class-ph]

Elodie Constanciel, Jean-Martial Mari, Samuel Pichardo, Francoise Chavrier, Cyril Lafon. Ellipsoid fitting for movement tracking and HIFU lesion simulation on mobile organs. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811319⟩