Thanks for posting a very interesting topic.
Unfortunately, I have no experience in MATLAB for image processing, and have no knowledge on SUSAN edge detector which seems to be based on enhanced 2D skeletonzation method.
I only have experience in automatic detection in SAR image in which signal-to-noise ratio is more terrible. Any effort using edge detection methods failed in that case.
I will appreciate if you let us know whether the edge detection works for your problem.
Best Regards,
-sy