Cannot segment an image of brain into white and grey matter

My aim is to extract both white and grey matter from the image ( http://imgur.com/6Zd04W1).

Tried many tools from MATLAB file exchange and some other softwares (MIPAV, SPV, etc.) so far to no avail. It looks like both white and grey matter have quite low contrast. Can anyone suggest some tricks to extract both white and grey matter?

Answer 1

[Image Analyst]

You will find algorithms for that here: http://iris.usc.edu/Vision-Notes/bibliography/contentsmedical.html#Medical%20Applications,%20CAT,%20MRI,%20Ultrasound,%20Heart%20Models,%20Brain%20Models Since I doubt simple thresholding will do it, you're on your own. We can't help with such complicated algorithm development here.

[Alex]

@Image Analyst, thank you very much for the link. Finally, I managed to work out the issue with http://www.mathworks.com/matlabcentral/fileexchange/24409-hessian-based-frangi-vesselness-filter

[Qvna Lhyvnav]

@Alex, which function that you used to extract the gray matter?