Is FCH PET able to identify foci of infection superiorly to FDG PET?

We report a case of a brain abscess identified on fluorine-18 choline (FCH) positron emission tomography (PET) scan, which was not identified on fluorodeoxyglucose (FDG) PET scan. To our knowledge, there are no previous case reports of incidental brain abscess identified by FCH PET imaging. A 51-year-old man, with liver cirrhosis complicated by hepatocellular carcinoma (HCC) was enrolled in a research trial comparing HCC detection in FCH PET versus FDG PET. During the course of the trial, he underwent radiofrequency ablation (RFA) for HCC. A repeat FCH PET scan post-RFA incidentally revealed a 2.5 cm lesion with avid uptake in the left occipital area of the brain. The patient was asymptomatic. MRI suggested this was an abscess. A craniotomy and drainage was performed, with culture of Streptococcus intermedius (S. milleri group) from the thick-walled collection, a causative organism for previous episode of pneumonia. He successfully completed a 6 week course of antibiotics.