Evaluation procedure

Protocol

Both the end diastolic and end systolic instances of the 45 acquired sequences of volumes have been manually segmented by three different experienced cardiologists:

• Marcel Geleijnse Erasmus University Medical Center, Rotterdam (Netherlands)
• Alexandros Papachristidis King's College London (United Kingdom)
• Elena Galli University of Rennes (France)

The manual/reference meshes were created using an in-house developed software package termed Speqle_3D (University of Leuven, Belgium). This package has already been used for several years by cardiologists for research purposes.

The following protocol has been followed for each acquisition. Four long-axis planes were selected at 45 degrees interval as well as five short axis planes equally spaced over the long axis. Left ventricle endocardial borders were manually traced in all nine planes at End-Diastolic and End-Systolic instances. In the long-axis planes, endocardial borders were drawn up until the mitral valve hinges. This allowed to accurately define the basal plane. The left ventricle trabeculations and papillary muscles were included within the left ventricle cavity, according to the American Society of Echocardiography guidelines (Lang, R.M. et al., 2005, Recommendations for chamber quatification. Journal of the American Society of Echocardiography 18(12), 1440-1463). Finally, from these contours a reference mesh was obtained by performing a least-squares surface fitting procedure through these contours.

Reference meshes properties

The properties of the reference meshes are consistent over the patients, the time instant and the cardiologist. The main properties are the following:

• Number of points: around 3200 points uniformally distributed along the surface
• Element type: triangle

Finally, each mesh is cutted and closed at the basal region of the heart by a plane. A specific care has to be taken here since this closed mesh (with a plane at the basal region) is used to compute the different distance measures. A typical cutted mesh before closing is given below.