On-line analysis of echocardiographic image sequences

This paper presents a semiautomatic system for the interactive analysis of echocardiographic image sequences, able to provide useful information to cardiologists. The proposed approach combines well known techniques for the detection of left ventricular boundaries with the computation of optical flow. The initial detection of the cavity contour is based on an improved balloon model, with automatic tuning of parameters and optional model-based constraints. The computation of optical flow is performed with a fast correlation technique and the contour tracking is obtained combining motion information provided by the optical flow with model-based constraints and/or a snake-based regularization. The system is able to follow the motion of the ventricular boundaries precisely, to provide several quantitative features of the heartbeat and a dynamic representation of systolic and diastolic motion. Preliminary experimental results are presented and commented on with particular attention to their clinical relevance. Furthermore, a distributed implementation of the system suitable for remote examination analysis has been realized and applied to echo images of the carotid artery.