title: Proton magnetic resonance spectroscopic imaging in pediatric pilomyxoid astrocytoma.
abstract: OBJECTIVE
  A pilomyxoid astrocytoma (PmA) is considered to be either a more aggressive variant of a pediatric pilocytic astrocytoma (PA) or a tumor of a separate entity.
  
  
  METHODS
  We present two cases of pediatric optic-chiasmatic PmA. Proton magnetic resonance spectroscopic imaging (MRSI) of the PmA revealed decreased concentrations of total choline (Cho), creatine (Cr), and N-acetyl aspartate (NAA). In contrast, proton MR spectra of PAs showed elevated Cho and decreased Cr and NAA signals.
  
  
  CONCLUSIONS
  Low metabolite concentrations in PmAs detected by MRSI may therefore help to distinguish PmAs from PAs preoperatively.
authors.affiliation: Division of Pediatric Neurosurgery, Department of Neurosurgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA. bayramcirak@yahoo.com
authors.forename: Bayram
authors.initials: B
authors.lastname: Cirak
authors.forename: Alena
authors.initials: A
authors.lastname: Horská
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burger
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Carson
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Avellino
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001254:Astrocytoma / Q000378:metabolism* / Q000473:pathology; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D002675:Child, Preschool; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D008297:Male
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline