We describe a system for the automatic detection of rib metastasis in thoracic CT volume. Rib metastasis manifest itself as alterations of bone intensities or shapes, and the detection of these alterations is the goal of the algorithm. According to the tubular shape of the rib structures, the detection is based on the construction of 2D cross-sections planes along the full lengths of each of the individual ribs. The set of planes is orthogonal to the rib centerline, with is extracted by a previously developed segmentation algorithm based on recursive tracing. On each of these planes, a 2D image is constructed by interpolation in the region of interest around the centerline intersection and the plane. From this image the cortical and trabecular bones are segmented separately. The appearance and geometric properties of the bone structures are analyzed and categorized according to a set of rules that summarize the possible variation types due to metastasis. The features extracted from the cross-sections along a short length of the centerline are jointly evaluated. A positive detection is accepted only if the alteration of shape and appearance is consistent with a number of consecutive cross-sections along the rib centerline.

Date Published: 29 March 2007
PDF: 7 pages
Proc. SPIE 6514, Medical Imaging 2007: Computer-Aided Diagnosis, 65140P (29 March 2007);

Published in SPIE Proceedings Vol. 6514:
Medical Imaging 2007: Computer-Aided Diagnosis
Maryellen L. Giger; Nico Karssemeijer, Editor(s)