title: Space-time segmentation using level set active contours applied to myocardial gated SPECT.
abstract: This paper presents a new variational method for the segmentation of a moving object against a still background, over a sequence of [two-dimensional or three-dimensional (3-D)] image frames. The method is illustrated in application to myocardial gated single photon emission computed tomography (SPECT) data, and incorporates a level set framework to handle topological changes while providing closed boundaries. The key innovation is the introduction of a geometrical constraint into the derivation of the Euler-Lagrange equations, such that the segmentation of each individual frame can be interpreted as a closed boundary of an object (an isolevel of a set of hyper-surfaces) while integrating information over the entire sequence. This results in the definition of an evolution velocity normal to the object boundary. Applying this method to 3-D myocardial gated SPECT sequences, the left ventricle endocardial and epicardial limits can be computed in each frame. This space-time segmentation method was tested on simulated and clinical 3-D myocardial gated SPECT sequences and the corresponding ejection fractions were computed.
authors.affiliation: Laboratoire I3S, Université de Nice-Sophia Antipolis, Biot, France. edebreuv@doug.med.utah.edu
authors.forename: E
authors.initials: E
authors.lastname: Debreuve
authors.forename: M
authors.initials: M
authors.lastname: Barlaud
authors.forename: G
authors.initials: G
authors.lastname: Aubert
authors.forename: I
authors.initials: I
authors.lastname: Laurette
authors.forename: J
authors.initials: J
authors.lastname: Darcourt
mesh_terms: D000465:Algorithms; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008433:Mathematics; D009068:Movement; D009206:Myocardium; D019047:Phantoms, Imaging; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*