title: Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy, diffusion and perfusion characteristics.
abstract: BACKGROUND
  We describe the magnetic resonance (MR) imaging characteristics of dysembryoplastic neuroepithelial tumors (DNT) and discuss their differential diagnosis.
  
  
  METHODS
  Proton MR spectroscopy (TE 30 and 136 ms), diffusion-weighted and perfusion images were retrospectively evaluated in 22 patients with pathologically proven DNT (17 male and 5 female, mean age 18.7 years) and 14 control subjects (10 male and 4 female, mean age 16.9 years). The results from the DNT patients and from the control subjects were compared using an independent sample t-test and the degree of correlation was tested by Pearson's correlation.
  
  
  RESULTS
  All DNTs were solitary and in a supratentorial cortical or subcortical location (ten temporal, eight frontal and four parietal). They had low-signal on T1-weighted images and high-signal on T2-weighted images without a prominent mass effect. Additionally a cystic appearance (six patients, 27.3%), cortical dysplasia (six patients, 27.3%) and contrast enhancement (four patients, 18.2%) were also noted. No significant differences were detected in NAA/Cho, NAA/Cr, NAA/Cho+Cr or Cho/Cr ratios between DNT and normal brain. DNTs had a significantly higher mI/Cr ratio and apparent diffusion coefficient (ADC) values and lower cerebral blood values than normal parenchyma (P < 0.001). ADC had the highest correlation with the diagnosis of DNT (r = 0.996) followed by relative cerebral blood volume (rCBV) (r = -0.883) and mI/Cr ratio (r = 0.663).
  
  
  CONCLUSIONS
  Proton MR spectroscopy, diffusion-weighted and perfusion imaging characteristics of DNTs provide additional information to their MR imaging findings. The MR spectrum showing a slight increase in mI/Cr ratio, and higher ADC and lower rCBV values than normal parenchyma help to differentiate DNTs from other cortical tumors, which had higher rCBV and lower ADC values than DNTs.
authors.affiliation: Department of Radiology, Military Medical Faculty, Gulhane Military Medical Academy, Etlik, 06018 Ankara, Turkey. nbulak@gata.edu.tr
authors.forename: Nail
authors.initials: N
authors.lastname: Bulakbasi
authors.forename: Murat
authors.initials: M
authors.lastname: Kocaoglu
authors.forename: Tuba H
authors.initials: TH
authors.lastname: Sanal
authors.forename: Cem
authors.initials: C
authors.lastname: Tayfun
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005910:Glioma / Q000098:blood supply* / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007294:Inositol / Q000378:metabolism; D018810:Magnetic Resonance Angiography; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D054220:Malformations of Cortical Development / Q000175:diagnosis / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000175:diagnosis / Q000473:pathology; D018242:Neuroectodermal Tumors, Primitive / Q000098:blood supply* / Q000175:diagnosis* / Q000473:pathology; D010296:Parietal Lobe / Q000098:blood supply / Q000473:pathology; D010725:Phosphocreatine / Q000378:metabolism; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000098:blood supply* / Q000175:diagnosis* / Q000473:pathology; D013702:Temporal Lobe / Q000098:blood supply / Q000473:pathology
chemical_list: D010725:Phosphocreatine; D007294:Inositol; D003401:Creatine; D002794:Choline