Remove frame from volume data

I have a volumetric dataset and I want to remove the frame from it to process on the actual scan. Attached you can see the volume I am dealing with. Any suggestions, how to do this?

Answer 1

[Rebecca Krosnick]

Are you trying to automatically remove the frame? Perhaps image segmentation features in the Image Processing Toolbox would be helpful: http://www.mathworks.com/help/images/image-segmentation-1.html

Alternatively, if you already know a boundary between the head and frame you can import the data into MATLAB and set all pixels outside of the head region to be 0.