Method for the automatic detection and segmentation of the spinal canal in computed tomographic images

Abstract

A method for the automatic 3-D segmentation of the spi- nal canal in computed tomographic (CT) images is presented. The method uses a priori radiological and anatomical information, math- ematical morphology, and region-growing methods. The skin and peripheral fat structures are determined by delineating the air and other materials external to the body. Using the fat layer as a refer- ence, the bone structure is segmented. The Hough transform for the detection of circles is applied to a cropped bone edge map that includes the thoracic vertebral structure. The centers of the detected circles are used to derive the information required for the fuzzy con- nectivity algorithm that is employed to segment the spinal canal. In a preliminary study, the method successfully segmented the spinal canal in eight CT volumes of four patients, with Hausdorff distances with reference to contours drawn independently by a radiologist in the range 1.7±0.8 mm. © 2006 SPIE and IS&T.