title: Diffusion characteristics of pediatric pineal tumors.
abstract: BACKGROUND
  Diffusion weighted imaging (DWI) has been shown to be helpful in characterizing tumor cellularity, and predicting histology. Several works have evaluated this technique for pineal tumors; however studies to date have not focused on pediatric pineal tumors.
  
  
  OBJECTIVE
  We evaluated the diffusion characteristics of pediatric pineal tumors to confirm if patterns seen in studies using mixed pediatric and adult populations remain valid.
  
  
  METHODS
  This retrospective study was performed after Institutional Review Board approval. We retrospectively evaluated all patients 18 years of age and younger with pineal tumors from a single institution where preoperative diffusion weighted imaging as well as histologic characterization was available.
  
  
  RESULTS
  Twenty patients (13 male, 7 female) with pineal tumors were identified: seven with pineoblastoma, four with Primitive Neuroectodermal Tumor (PNET), two with other pineal tumors, and seven with germ cell tumors including two germinomas, three teratomas, and one mixed germinoma-teratoma. The mean apparent diffusion coefficient (ADC) values in pineoblastoma (544 ± 65 × 10⁻⁶ mm²/s) and pineoblastoma/PNET (595 ± 144 × 10⁻⁶ mm²/s) was lower than that of the germ cell tumors (1284 ± 334 × 10⁻⁶ mm²/s; p < 0.0001 vs pineoblastoma). One highly cellular germinoma had an ADC value of 694 × 10⁻⁶ mm²/s.
  
  
  CONCLUSIONS
  ADC values can aid in differentiation of pineoblastoma/PNET from germ cell tumors in a population of children with pineal masses.
authors.affiliation: Department of Radiology, University of Tennessee Health Science Center, USA Department of Neurosurgery, University of Tennessee Health Science Center, USA Department of Ophthalmology, University of Tennessee Health Science Center, USA Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, USA achoudhri@uthsc.edu.
authors.forename: Asim F
authors.initials: AF
authors.lastname: Choudhri
authors.affiliation: Department of Radiology, University of Tennessee Health Science Center, USA Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, USA Department of Radiology, Children's National Medical Center, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Whitehead
authors.affiliation: Department of Radiology, University of Tennessee Health Science Center, USA Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, USA.
authors.forename: Adeel
authors.initials: A
authors.lastname: Siddiqui
authors.affiliation: Department of Neurosurgery, University of Tennessee Health Science Center, USA Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, USA Semmes-Murphey Neurologic and Spine Institute, USA Division of Neurosurgery, St Jude Children's Hospital, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Klimo
authors.affiliation: Department of Neurosurgery, University of Tennessee Health Science Center, USA Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, USA Semmes-Murphey Neurologic and Spine Institute, USA Division of Neurosurgery, St Jude Children's Hospital, USA.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Boop
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010870:Pineal Gland / Q000473:pathology*; D010871:Pinealoma / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: diffusion weighted imaging; germ cell tumor; germinoma; pineal tumor; pineoblastoma