Share Email Print

Proceedings Paper

Level sets on non-planar manifolds for ridge detection on isosurfaces
Author(s): Sovira Tan; Jianhua Yao; Michael M. Ward M.D.; Lawrence Yao M.D.; Ronald M. Summers M.D.
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

We describe an algorithm for evolving a level set on a non-planar manifold like the isosurface of a 3D object. The surface is represented by a triangular mesh and the feature that guides our level set via a speed function is its curvature. We overcome the difficulty of computing the gradient and curvature of the level set distance function on a non-planar, non-Cartesian mesh by performing the calculations locally in neighborhoods small enough to be considered planar. Moreover we use a least squares estimation of derivatives to replace finite differences and achieve better accuracy. The algorithm was motivated by our need to detect the ridge lines of vertebral bodies. The advantage of using level sets is that they are capable of producing a continuous ridge line despite noise and gaps in the ridge. We tested our algorithm on 40 vertebral bodies (80 ridge lines). 76 ridge lines showed no noticeable mistakes. The same set of parameters was used. For the remaining 4, we had to change the parameters of the speed function sigmoid to correct small under- or over-segmenting. To further test our algorithm we designed a synthetic surface with large curvature and to which we added noise and a ridge. The level set was able to evolve on the surface and stop at the ridge. Tests on synthetic cylinders with a ground truth ridge and to which we added noise indicate that the level set has good accuracy.

Paper Details

Date Published: 5 March 2007
PDF: 12 pages
Proc. SPIE 6512, Medical Imaging 2007: Image Processing, 651230 (5 March 2007); doi: 10.1117/12.708217
Show Author Affiliations
Sovira Tan, National Institutes of Health (United States)
Jianhua Yao, National Institutes of Health (United States)
Michael M. Ward M.D., National Institutes of Health (United States)
Lawrence Yao M.D., National Institutes of Health (United States)
Ronald M. Summers M.D., National Institutes of Health (United States)

Published in SPIE Proceedings Vol. 6512:
Medical Imaging 2007: Image Processing
Josien P. W. Pluim; Joseph M. Reinhardt, Editor(s)

© SPIE. Terms of Use
Back to Top