Jan D'hooge

Bio: Jan D'hooge is an academic researcher from Katholieke Universiteit Leuven. The author has contributed to research in topics: Image segmentation & Segmentation. The author has an hindex of 59, co-authored 544 publications receiving 13729 citations. Previous affiliations of Jan D'hooge include The Catholic University of America & University of Copenhagen Faculty of Science.

Regional Strain and Strain Rate Measurements by Cardiac Ultrasound: Principles, Implementation and Limitations

Abstract: The non-invasive quantification of regional myocardial function is an important goal in clinical cardiology. Myocardial thickening/thinning indices is one method of attempting to define regional myocardial function. A new ultrasonic method of quantifying regional deformation has been introduced based on the principles of 'strain' and 'strain rate' imaging. These new imaging modes introduce concepts derived from mechanical engineering which most echocardiographers are not familiar with. In order to maximally exploit these new techniques, an understanding of what they measure is indispensable. This paper will define each of these modalities in terms of physical principles and will give an introduction to the principles of data acquisition and processing required to implement ultrasonic strain and strain rate imaging. In addition, the current status of development of the technique and its limitations will be discussed, together with examples of potential clinical applications.

Standardization of left atrial, right ventricular, and right atrial deformation imaging using two-dimensional speckle tracking echocardiography: a consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging.

Abstract: The EACVI/ASE/Industry Task Force to standardize deformation imaging prepared this consensus document to standardize definitions and techniques for using two-dimensional (2D) speckle tracking echocardiography (STE) to assess left atrial, right ventricular, and right atrial myocardial deformation. This document is intended for both the technical engineering community and the clinical community at large to provide guidance on selecting the functional parameters to measure and how to measure them using 2D STE.This document aims to represent a significant step forward in the collaboration between the scientific societies and the industry since technical specifications of the software packages designed to post-process echocardiographic datasets have been agreed and shared before their actual development. Hopefully, this will lead to more clinically oriented software packages which will be better tailored to clinical needs and will allow industry to save time and resources in their development.

Strain and strain rate imaging: a new clinical approach to quantifying regional myocardial function.

Abstract: On the basis of color Doppler myocardial motion data, 1-dimensional regional natural strain rate and strain curves can now be calculated by comparing local myocardial velocity profiles. Such deformation data sets may be an important, new, and more sensitive approach to quantifying both regional radial and long-axis function of the left or right ventricle in both acquired and congenital heart disease. The normal ranges of regional velocity, strain rate, and strain values have already been determined in both adults and children. This review will focus both on the potential clinical applications of these new ultrasound-based deformation parameters and the current limitations inherent in implementing the technique in everyday practice.

Experimental Validation of a New Ultrasound Method for the Simultaneous Assessment of Radial and Longitudinal Myocardial Deformation Independent of Insonation Angle

Abstract: Background— Strain and strain rate have been proposed as tools to quantify regional myocardial function. One of the major pitfalls of the current methodology is its angle dependency. To overcome this problem, we have developed a new method for the estimation of strain, independent of angle. The aim of this study was to validate this new methodology in an experimental setting using sonomicrometry. Methods and Results— In 5 open-chest sheep, ultrasound data were acquired. The new methodology was used to perform simultaneous measurements of radial and longitudinal strain in the inferolateral wall. Segment-length sonomicrometry crystals were used as the reference. After baseline acquisitions, deformation was modulated by pharmacologically changing the inotropic state of the myocardium and by inducing ischemia. Ultrasonically estimated radial and longitudinal strain were validated against sonomicrometry by means of Bland-Altman analysis and the intraclass correlation coefficient. For both strain components, go...

Can natural strain and strain rate quantify regional myocardial deformation? A study in healthy subjects

Abstract: Strain rate (SR) and strain (epsilon) have been proposed as new ultrasound (US) indices for quantifying regional wall deformation, and can be measured from color Doppler myocardial data by determining the local spatial velocity gradient. The aim of this study was to define normal regional SR/epsilon values for both radial and longitudinal myocardial deformation. SR/epsilon profiles were obtained from 40 healthy volunteers. For radial deformation, posterior left ventricular (LV) wall SR/epsilon were calculated. For longitudinal, they were determined for basal, mid- and apical segments of the 1. septum; 2. lateral, 3. posterior and 4. anterior LV walls and for the 5. right ventricular (RV) lateral wall. SR/epsilon values describing radial deformation were higher than the corresponding SR/epsilon values obtained for longitudinal deformation. Longitudinal SR/epsilon were homogeneous throughout the septum and all LV walls. This was in contrast to the normal base-apex velocity gradient. The RV segmental SR/epsilon values were higher than those obtained from the corresponding LV wall and inhomogeneous (higher in the apical segments). SR/epsilon imaging appears to be a robust technique for quantifying regional myocardial deformation.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.

Abstract: The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Pattern Recognition and Machine Learning

Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography Endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography

Abstract: on Statement: Society of Echocardiography is accreditedby theAccreditationCouncil for edical Education to provide continuingmedical education for physicians. n Society of Echocardiography designates this educational activity for of 1.0 AMA PRA Category 1 Credits . Physicians should only claim credit te with the extent of their participation in the activity. CCI recognize ASE’s certificates and have agreed to honor the credit hours registry requirements for sonographers. Society of Echocardiography is committed to ensuring that its educational ll sponsored educational programs are not influencedby the special interests ation or individual, and itsmandate is to retain only those authors whose fists canbeeffectively resolved tomaintain thegoals andeducational integrity y. While a monetary or professional affiliation with a corporation does not fluence an author’s presentation, the Essential Areas and policies of the ire that any relationships that could possibly conflict with the educational activity be resolved prior to publication and disclosed to the audience. f faculty and commercial support relationships, if any, have been indicated. ience: is designed for all cardiovascular physicians and cardiac sonographers with erest and knowledge base in the field of echocardiography; in addition, reschers, clinicians, intensivists, and other medical professionals with a spein cardiac ultrasound will find this activity beneficial.

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography

Abstract: on Statement: Society of Echocardiography is accredited by the Accreditation Council for edical Education to provide continuing medical education for physicians. n Society of Echocardiography designates this educational activity for of 1.0 AMA PRA Category 1 Credits . Physicians should only claim credit te with the extent of their participation in the activity. CCI recognize ASE’s certificates and have agreed to honor the credit hours registry requirements for sonographers. Society of Echocardiography is committed to ensuring that its educational ll sponsored educational programs are not influenced by the special interests ation or individual, and its mandate is to retain only those authors whose fists can be effectively resolved to maintain the goals andeducational integrity y. While a monetary or professional affiliation with a corporation does not fluence an author’s presentation, the Essential Areas and policies of the ire that any relationships that could possibly conflict with the educational activity be resolved prior to publication and disclosed to the audience. f faculty and commercial support relationships, if any, have been indicated. ience: is designed for all cardiovascular physicians and cardiac sonographers with erest and knowledge base in the field of echocardiography; in addition, reschers, clinicians, intensivists, and other medical professionals with a spein cardiac ultrasound will find this activity beneficial.

V-Net: Fully Convolutional Neural Networks for Volumetric Medical Image Segmentation

Abstract: Convolutional Neural Networks (CNNs) have been recently employed to solve problems from both the computer vision and medical image analysis fields. Despite their popularity, most approaches are only able to process 2D images while most medical data used in clinical practice consists of 3D volumes. In this work we propose an approach to 3D image segmentation based on a volumetric, fully convolutional, neural network. Our CNN is trained end-to-end on MRI volumes depicting prostate, and learns to predict segmentation for the whole volume at once. We introduce a novel objective function, that we optimise during training, based on Dice coefficient. In this way we can deal with situations where there is a strong imbalance between the number of foreground and background voxels. To cope with the limited number of annotated volumes available for training, we augment the data applying random non-linear transformations and histogram matching. We show in our experimental evaluation that our approach achieves good performances on challenging test data while requiring only a fraction of the processing time needed by other previous methods.