Does anybody know what an abnormal pet scan is?

Yes. But I cannot give you the answer without knowing why the scan was performed. An abnormal scan most likely is because there is an area in your body that is more metabolically active, than expected. But pet scans are done as pet/ct scans and abnormality could be in the ct part. ..Which could be anything. ..Anatomically not "normal". These ct findings could be "normal" for you but not me. Ask ur md.
Yes!! Positron emission tomography (pet scan) is a form of study mainly of the metabolism and the chemical content of the brain. It has fewer indications than the ct or the mri.