Problem with dicomwrite pixel values

I've been working on a project where I use the DICOM write function to save my files after procesing, values of my matrix go from -1024 to 3072, however, after writing, scale changes and now they're between -2048:2048. My code is as follows:

M=int16(M);
dicomwrite(M,filename,info);

Any help would be truly apreciated.