How can I segment endocardium?

Hy everyone, I'm a newbie in Matlab and Image processing toolbox. Could someone suggest me a way to segment the endocardium contour in my image (slice)? Thanks

[Rik]

Have a read here, there are a bunch of hints of how you can find your own answers and how to improve the question you post.

Segmentation is an entire field of research. Therefor it shouldn't surprise you that there is no general answer to your question. If you want an answer for your situation, add the slice to your post and show what you have tried thus far.

[Image Analyst]

Also check for prior papers on it here: http://www.visionbib.com/bibliography/contentsmedical.html#Medical%20Applications,%20CAT,%20MRI,%20Ultrasound,%20Heart%20Models,%20Brain%20Models