Dear Ali,

       If you are working on brain tumor segmentation, then the best choice is  Brats challenge dataset which comes with ground truths for different lesions. You can find it here:

https://www.smir.ch/BRATS/Start2015

Thank you Mr Ahmed 

I downloaded the dataset but I do not know how can I use these files with (mha) format because it is completely different from dicom files

Regards

Ali

You can use many visualization software. MITK can be used for this purpose with other different facilities. You can find it here:

http://mitk.org/wiki/MITK

Good Luck

Dear Mr Ahmed

I am so grateful

I use Matlab to read the mha files but unfortunately the read images are in black and white not in grey scale, how can I use them to compare them with my result of segmentation

Regards

Ali 

Dear Ali,

            In most of cases you have to normalize the voxel values first to keep in range i.e. 0 to 255. 

Another hint: you may use empty square braces in imshow function to avoid showing the images in black and white.

Dear Ahmed

Thank so much and I am so grateful

Regards

Ali