title: Subependymal giant cell astrocytoma with high choline/creatine ratio on proton MR spectroscopy.
abstract: OBJECTIVE
  To report a case of subependymal giant cell astrocytoma (SEGA) in a patient with tuberous sclerosis, emphasizing the proton MR spectroscopy (MRS) findings.
  
  
  METHODS
  A three year-old boy with tuberous sclerosis presented with a 3-month history of mild headache. The physical examination showed discrete mental retardation and multiple hypomelanic macules in the legs and back. MRI showed many cortical tubers and subependymal nodules. At the left foramen of Monro, there was a 15 mm nodule, with heterogeneous signal on T1 and T2-weighted images, and strong enhancement after contrast administration. MRS study (multi-voxel PRESS, TE=144ms) showed the following ratios: a) left foramen of Monro nodule N-acetylaspartate (NAA)/creatine (Cr)=0.93 and Choline (Cho)/Cr=1.6 and b) at the right Monro foramen NAA/Cr=1.56 and Cho/Cr=1.29.
  
  
  CONCLUSIONS
  The MRS performed at the SEGA may show high Cho/Cr and low NAA/Cr ratios, similar to the other brain neoplasms. As a consequence, MRS may be a valuable tool for the early detection of neoplastic transformation of subependymal nodules near the foramina of Monro in patients with tuberous sclerosis.
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, University of Parana, Rua Brigadeiro Franco 122, 80430-210 Curitiba PR, Brazil. arnolfocarvalho@hotmail.com
authors.forename: Arnolfo
authors.initials: A
authors.lastname: de Carvalho Neto
authors.forename: Emerson L
authors.initials: EL
authors.lastname: Gasparetto
authors.forename: Isac
authors.initials: I
authors.lastname: Bruck
mesh_terms: D001254:Astrocytoma / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D002675:Child, Preschool; D002794:Choline / Q000032:analysis*; D003401:Creatine / Q000032:analysis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D014402:Tuberous Sclerosis / Q000150:complications*
chemical_list: D014408:Biomarkers, Tumor; D003401:Creatine; D002794:Choline