Septal Flash Assessment on CRT Candidates Based on Statistical Atlases of Motion

Abstract

Abstract. In this paper, we propose a complete framework for the automatic detection and quantification of abnormal heart motion patterns using Statistical Atlases of Motion built from healthy populations. The method is illustrated on CRT patients with identified cardiac dyssynchrony and abnormal septal motion on 2D ultrasound (US) sequences. The use of the 2D US modality guarantees that the temporal resolution of the image sequences is high enough to work under a small displacements hypothesis. Under this assumption, the computed displacement fields can be directly considered as cardiac velocities. Comparison of subjects acquired with different spatiotemporal resolutions implies the reorientation and temporal normalization of velocity fields in a common space of coordinates. Statistics are then performed on the reoriented vector fields. Results show the ability of the method to correctly detect abnormal motion patterns and quantify their distance to normality. The use of local p-values for quantifying abnormal motion patterns is believed to be a promising strategy for computing new markers of cardiac dyssynchrony for better characterizing CRT candidates.

A spatiotemporal statistical atlas of motion for the quantification of abnormal myocardial tissue velocities

“…The method is applied to the analysis of a population of CRT patients with left ventricular dyssynchrony, looking for the presence of SF. A first preliminary version of this work was presented in Duchateau et al (2009), in which we illustrated the feasibility of such an approach for assessing abnormality on a reduced number of patients.…”

A groupwise mutual information metric for cost efficient selection of a suitable reference in cardiac computational atlas construction

“…Our nonrigid transformation is modeled as a composition of B-splines, each of which is constrained to be diffeomorphic, 8 and at increasing level of detail. 9 The total transformation is given by T total = T 8 • T 16 • T 32 , with the subscripts indicating, in millimeters, the B-spline control point grid spacings. As each of the three deformations in the composition is diffeomorphic, T total is also guaranteed to be diffeomorphic.…”

Atlas-Based Quantification of Myocardial Motion Abnormalities: Added-value for the Understanding of CRT Outcome?

“…The atlas pipeline described in [12] was applied on the 4-chamber sequences of the two populations described in Sec. 2.1.…”

“…Patient comparison in terms of cardiac motion and deformation was proposed in [9], [10] and [11], using the framework of statistical atlases. In particular, an atlas-based pipeline for the quantification of myocardial motion abnormalities has recently been described in [12]. This pipeline characterized myocardial velocities of the studied patients according to their distance to normality, in a similar fashion than proposed in [13] for the detection of brain abnormalities.…”

“…Our aim is to demonstrate the added value of such an atlas-based distance to normality for the study of response to CRT. We use the local abnormality indexes proposed in [12] to accurately quantify improvements in wall motion induced by CRT. We finally relate the changes in local abnormalities with information about CRT outcome, in order to understand the causes of non-response to the therapy.…”