Can CT scan without contrast show any brain tumors?

Sometimes. Brain swelling, hemorrhage and mass effect can be noted on a head ct without contrast. Also, some tumors have calcification a which can be seen in a head ct. Smaller and lower grade tumors can sometimes be missed on a head ct without contrast.
Yes. A ct scan will show brain tumors if they are large enough, have calcium or blood in them, or are causing swelling. On some occasions, contrast is necessary to see other types of tumors.

Related Questions

Had a fear of brain tumor for 7 months. Ct scan without contrast was clean. Would I be having severe symptoms by now if it was malignant?

Brain tumors aren't easily categorized into benign or malignant. Although the most aggressive type of brain tumor, glioblastoma, would likely be causing severe symptoms by now, there are other types of brain tumors that can be serious but not grow as quickly. The majority, however, would be associated with progressive symptoms during this time period. An MRI is the best test to evaluate potential masses in the brain. Read more...

What types of brain tumors won't show up on a CT scan?

Small low grade mass. Some small low grade tumors that have not incited vasogenic edema could be missed on ct scanning. The addition of IV contrast would improve visualization of some tumors, but ct has limits in resolution when compared to mri. These are not the tumors that cause profound symptoms, frequently these small tumors are found incidentally when patients have scans for other reasons. Read more...