Dice similarity coefficient grayscale DICOM images

Hi all

I have 2 DICOM images one is the ground truth and the other is an image which has been registered to this ground truth.

Is it possible to find the DSC for these grayscale images?

I understand that the DSC for binary images can be found using the code from the other question on DSc found here dice = 2*nnz(segIm&grndTruth)/(nnz(segIm) + nnz(grndTruth))

However having tested it on numerous int16 DICOM images i sometimes get an answer above 1.

So is it possible to compute the DSC for 2 DICOM images in matlab?

Thanks in advance for any help!!