A mri without dye show a brain tumor?

Yes: Yes a non-contrast MRI is pretty good for detecting a tumor in the brain, but using contrast "dye" improves the ability of an MRI to detect a small tumor.

Yes: Mri scans are often very good at showing brain tumors without the use of contrast substances (not actually "dyes"). Mris are done with different radio pulse sequences and these are often excellent ways to find and delineate information about a tumor. Contrast provides additional information and very occasionally allows one to find a tumor which would have been missed without contrast.

It can: If you'll give us more information, we'll be glad to help you find resources. First though you'll probably want to sit down with your personal physician and talk about the results.

What's the question?: Certainly many, perhaps most brain tumors will show on an MRI without contrast ("dye"). If that's the question, the answer is yes. What you are asking is otherwise not at all clear, sorry.