Shape-based retrieval of vertebral X-ray images is a challenging task because of high similarity among the vertebral shapes. Most techniques, such as global shape properties or scale space filtering, lose or fail to detect local details. As the result of this shortfall, the number of retrieved images is so high that the retrieval result is sometimes meaningless. To retrieve a small number of best matched images, shape representation and similarity measurement techniques must distinguish shapes with minor variations. The main challenge of shape-based retrieval is to define a shape representation method that is invariant with respect to rotation, translation, scaling, and the curve starting point shift. In this research, a polygon curve evolution technique was developed for smoothing polygon curves and reducing the number of data points while preserving the significant pathology of the shape.

 Project Sponsors:

 National Library of Medicine (2002)

 Collaborators:

 Dr. Sameer Antani, National Library of Medicine
 Mr. L. Rodney Long, National Library of Medicine
 Dr. George Thoma, National Library of Medicine

 Graduate Students:

 Xiaoqian Xu

1. S.K. Antani, D.J. Lee, L.R. Long, and G.R. Thoma, ?Evaluation of Shape Similarity Measurement Methods for Spine X-Ray Images ?, Special issue on  "Multimedia Database Management Systems" of the Journal of Visual Communication and Image Representation, vol. 15/3, p. 285-302, September 2004.

2. S.K. Antani, L.R. Long, G.R. Thoma, and D.J. Lee, ? Anatomical Shape Representation in Spine X-ray Image ?, Proceedings of IASTED International Conference on Visualization, Imaging and Image Processing, p. 510-515, Benalmadena, Spain, September 8-10, 2003.

3. D.J. Lee, S.K. Antani, and L.R. Long, ? Similarity Measurement Using Polygon Curve Representation and Fourier Descriptors for Shape-based Vertebral Image Retrieval ? SPIE Medical Imaging, Image Processing, vol. 5032, p. 1283-1291, San Diego, CA, USA, February 16-20, 2003.

4. L.R. Long, S.K. Antani, D.J. Lee, D. Krainak, and G.R. Thoma, ?Biomedical Information from a National Collection of Spine X-rays:  Film to Content-based Retrieval ?, SPIE Medical Imaging, PACS and Integrated Medical Information Systems: Design and Evaluation, vol. 5033, p. 70-84, San Diego, CA, USA, February 16-20, 2003.

5. S.K. Antani, L.R. Long, G.R. Thoma, and D.J. Lee, ? Evaluation of Shape Indexing Methods for Content-Based Retrieval of X-Ray Images ?, SPIE Electronic Imaging, Storage and Retrieval for Media Databases, vol. 5021, p. 405-416, Santa Clara, CA, USA, January 19-23, 2003.