Can a glioma be diagnosed without a biopsy?

If the answer is no, then does that mean Senator Kennedy had a biopsy
of his brain? Doesn't that require surgically going through the skull
to do the biopsy?

I've seen no news that he had a biopsy, but it seems that he most
likely did.

Or is there some other test other than a biopsy that confirms a glioma?