title: Metastatic liver tumour segmentation from discriminant Grassmannian manifolds.
abstract: The early detection, diagnosis and monitoring of liver cancer progression can be achieved with the precise delineation of metastatic tumours. However, accurate automated segmentation remains challenging due to the presence of noise, inhomogeneity and the high appearance variability of malignant tissue. In this paper, we propose an unsupervised metastatic liver tumour segmentation framework using a machine learning approach based on discriminant Grassmannian manifolds which learns the appearance of tumours with respect to normal tissue. First, the framework learns within-class and between-class similarity distributions from a training set of images to discover the optimal manifold discrimination between normal and pathological tissue in the liver. Second, a conditional optimisation scheme computes non-local pairwise as well as pattern-based clique potentials from the manifold subspace to recognise regions with similar labelings and to incorporate global consistency in the segmentation process. The proposed framework was validated on a clinical database of 43 CT images from patients with metastatic liver cancer. Compared to state-of-the-art methods, our method achieves a better performance on two separate datasets of metastatic liver tumours from different clinical sites, yielding an overall mean Dice similarity coefficient of [Formula: see text] in over 50 tumours with an average volume of 27.3 mm(3).
authors.affiliation: Ecole Polytechnique de Montréal, Succursale Centre-Ville, PO Box 3079 Montréal, QC H3C 3A7, Canada. CHU Sainte-Justine Hospital Research Center, Montréal, QC H3T 1C4, Canada.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kadoury
authors.forename: Eugene
authors.initials: E
authors.lastname: Vorontsov
authors.forename: An
authors.initials: A
authors.lastname: Tang
mesh_terms: D000465:Algorithms; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D000069550:Machine Learning