skip to main content


Search for: All records

Editors contains: "Clarysse, Patrick"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Bernard, Olivier ; Clarysse, Patrick ; Duchateau, Nicolas ; Ohayon, Jacques ; Viallon, Magalie. (Ed.)
    In this work we present a machine learning model to segment long axis magnetic resonance images of the left ventricle (LV) and address the challenges encountered when, in doing so, a small training dataset is used. Our approach is based on a heart locator and an anatomically guided UNet model in which the UNet is followed by a B-Spline head to condition training. The model is developed using transfer learning, which enabled the training and testing of the proposed strategy from a small swine dataset. The segmented LV cavity and myocardium in the long axis view show good agreement with ground truth segmentations at different cardiac phases based on the Dice similarity coefficient. In addition the model provides a measure of segmentations' uncertainty, which can then be incorporated while developing LV computational models and indices of cardiac performance based on the segmented images. Finally, several challenges related to long axis, as opposed to short axis, image segmentation are highlighted, including proposed solutions. 
    more » « less
    Free, publicly-accessible full text available June 16, 2024
  2. Bernard, Olivier ; Clarysse, Patrick ; Duchateau, Nicolas ; Ohayon, Jacques ; Viallon, Magalie (Ed.)
    Porcine hearts (N = 14) underwent ex vivo diffusion tensor imaging (DTI) at 3T. DTI analysis showed regional differences in helix angle (HA) range. The HA range in the posterior free wall was significantly greater than that of the anterior free wall (p = 0.02), the lateral free wall (p < 0.001) and the septum (p = 0.008). The best-fit transmural HA function also varied by region, with eight regions best described by an arctan function, seven by an arcsine function, and a single region by a linear function. Tractography analysis was performed, and the length that the tracts spanned within the epicardial, midwall, and endocardial segments was measured. A high number of tracts span the epicardial and mid-wall thirds, with fewer tracts spanning the mid-wall and endocardial thirds. Connectivity analysis of the number of tracts connecting different ventricular regions showed a high prevalence of oblique tracts that may be critical for long-range connectivity. 
    more » « less
    Free, publicly-accessible full text available June 16, 2024
  3. Bernard, Olivier ; Clarysse, Patrick ; Duchateau, Nicolas ; Ohayon, Jacques ; Viallon, Magalie (Ed.)
    Porcine hearts (N = 14) underwent ex vivo diffusion tensor imaging (DTI) at 3T. DTI analysis showed regional differences in helix angle (HA) range. The HA range in the posterior free wall was significantly greater than that of the anterior free wall (p = 0.02), the lateral free wall (p < 0.001) and the septum (p = 0.008). The best-fit transmural HA function also varied by region, with eight regions best described by an arctan function, seven by an arcsine function, and a single region by a linear function. Tractography analysis was performed, and the length that the tracts spanned within the epicardial, midwall, and endocardial segments was measured. A high number of tracts span the epicardial and mid-wall thirds, with fewer tracts spanning the mid-wall and endocardial thirds. Connectivity analysis of the number of tracts connecting different ventricular regions showed a high prevalence of oblique tracts that may be critical for long-range connectivity. 
    more » « less
    Free, publicly-accessible full text available June 16, 2024