Posterior fossa arachnoid cysts.
D000293:Adolescent; D000328:Adult; D001099:Arachnoid / Q000000981:diagnostic imaging; D001927:Brain Diseases / Q000000981:diagnostic imaging*; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging; D003560:Cysts / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D011877:Radionuclide Imaging