how to do segmentation

Sir please refer the link....

http://img405.imageshack.us/img405/8226/80692243.png

the link shows automatic segmentation of thyroid gland from ultrasound images of thyroid..... i searched for thyroid segmentation codes... but didnt find even one code for thyroid segmentation..... so i tried the available codes for other segmentation techniques.... but the outputs i'm getting is not even close to one i have showed.... please can anyone help me in segmentating that image atleast if it does not look as shown in the image, at least somewhat like it..... please do reply.... i would be great help for me......

[Elysi Cochin]

These are the images i'm working on..... please reply.... it would be great help for me sir.....

http://img208.imageshack.us/img208/2262/31285232.png

http://img594.imageshack.us/img594/807/33371327.png

http://img69.imageshack.us/img69/6011/31338206.png

http://img706.imageshack.us/img706/4669/36605500.png

Answer 1

[Image Analyst]

It looks like there are some papers on the topic of thyroid segmentation, measurement, and interpretation:

http://www.google.com/search?hl=En&as_sitesearch=www.visionbib.com%2F&bthG=Google%2BSearch&q=thyroid