title: Three-dimensional multivoxel proton MR spectroscopy of the brain in children with neurofibromatosis type 1.
abstract: OBJECTIVE
  Neurofibromatosis type 1 (NF1), the most common autosomal dominant genetic disorder, frequently manifests as focal areas of signal intensity (FASI) on T2-weighted MR images. The purpose of our study was to investigate whether tumor(s), focal areas of signal intensity (FASI), and normal brain can be differentiated by using 3D multivoxel localized proton MR spectroscopy in children with neurofibromatosis type 1 (NF1) disorder.
  
  
  METHODS
  Five children with NF1 and two healthy control subjects, all in the 3- to 11-year-old age group, were studied with a new 3D proton MR spectroscopy technique: a hybrid of 1D fourth-order transverse Hadamard spectroscopic imaging and 2D chemical shift imaging. A 3D volume-of-interest (VOI) was image-guided onto the site of the abnormality and identified on three orthogonal images. Proton MR spectroscopy partitioned the VOI into 6 x 6 x 4 (or 8 x 8 x 4) voxels, 1.5 (or 1.0) cm3 each.
  
  
  RESULTS
  Simultaneous coverage of the entire VOI yielded good spectral signal-to-noise ratio from 136 (or 256) voxels in 27 minutes. Proton MR spectroscopy indicated that FASI a) are characterized by significantly elevated choline (Cho), reduced creatine (Cr), 2>Cho: Cr>1.3, and near normal N-acetylaspartate (NAA) levels; b) are different from tumors that exhibit Cho:Cr>2 and no NAA; c) have no intrinsic lipid or lactate signal(s); and d) correlate in spatial extent but are more extensive than indicated by MR imaging.
  
  
  CONCLUSIONS
  Three-dimensional multivoxel proton MR spectroscopy reveals distinct metabolic features that differentiate normal, FASI, and tumor regions in the pediatric brain.
authors.affiliation: Division of Medical Science, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: O
authors.initials: O
authors.lastname: Gonen
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Wang
authors.forename: A K
authors.initials: AK
authors.lastname: Viswanathan
authors.forename: P T
authors.initials: PT
authors.lastname: Molloy
authors.forename: R A
authors.initials: RA
authors.lastname: Zimmerman
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001921:Brain / Q000473:pathology; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D009456:Neurofibromatosis 1 / Q000175:diagnosis*
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline