Neuroradiologists are medical doctors who specialize in the analysis of brain scans. These scans can be angiograms, MRI scans, CAT scans, PET scans, electroencephalograms, or something else entirely, but whatever the modality, neuroradiologists are the ones who figure out whether something funny is going on in your brain.
Really skilled neuroradiologists are mild obsessive-compulsives who can find a needle in a haystack. I've judged scans as totally normal only to have a neuroradiologist reach over my shoulder and point out a 1-millimeter dim spot in the back of the brainstem. That's why they get the big money and I don't.