Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy, diffusion and perfusion characteristics.
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.
Bulakbasi
Nail
N
Department of Radiology, Military Medical Faculty, Gulhane Military Medical Academy, Etlik, 06018 Ankara, Turkey. nbulak@gata.edu.tr
Kocaoglu
Murat
M
Sanal
Tuba H
TH
Tayfun
Cem
C
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
D010725:Phosphocreatine; D007294:Inositol; D003401:Creatine; D002794:Choline