title: A multi-center 1H MRS study of the AIDS dementia complex: validation and preliminary analysis.
abstract: OBJECTIVE
  To demonstrate the technical feasibility and reliability of a multi-center study characterizing regional levels of the brain metabolite ratios choline (Cho)/creatine (Cr) and myoinositol (MI)/Cr, markers of glial cell activity, and N-acetyl aspartate (NAA)/Cr, a marker of mature neurons, in subjects with AIDS dementia complex (ADC).
  
  
  METHODS
  Using an automated protocol (GE PROBE-P), short echo time spectra (TE = 35 msec) were obtained at eight sites from uniformly prepared phantoms and from three brain regions (frontal white matter, basal ganglia, and parietal cortex) of normal volunteers and ADC and HIV-negative subjects.
  
  
  RESULTS
  A random-effects model of the phantom and volunteer data showed no significant inter-site differences. Feasibility of a multi-center study was further validated by detection of significant differences between the metabolite ratios of ADC subjects and HIV-negative controls. ADC subjects exhibited significantly higher Cho/Cr and MI/Cr in the basal ganglia and significantly reduced NAA/Cr and significantly higher MI/Cr in the frontal white matter. These results are consistent with the predominantly subcortical distribution of the pathologic abnormalities associated with ADC.
  
  
  CONCLUSIONS
  This is the first study to ascertain and validate the reliability and reproducibility of a short echo time (1)H-MRS acquisition sequence from multiple brain regions in a multi-center setting. It should now be possible to examine the regional effects of HIV infection in the brain in a large number of subjects and to study the metabolic effects of new therapies for the treatment of ADC in a clinical trial setting.
authors.affiliation: NMR Center, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02111, USA. bnavia@lifespan.org
authors.forename: Patricia Lani
authors.initials: PL
authors.lastname: Lee
authors.forename: Constantin T
authors.initials: CT
authors.lastname: Yiannoutsos
authors.forename: Thomas
authors.initials: T
authors.lastname: Ernst
authors.forename: Linda
authors.initials: L
authors.lastname: Chang
authors.forename: Christina M
authors.initials: CM
authors.lastname: Marra
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Jarvik
authors.forename: Todd L
authors.initials: TL
authors.lastname: Richards
authors.forename: Edmund W
authors.initials: EW
authors.lastname: Kwok
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Kolson
authors.forename: David
authors.initials: D
authors.lastname: Simpson
authors.forename: Cheuk Y
authors.initials: CY
authors.lastname: Tang
authors.forename: Giovanni
authors.initials: G
authors.lastname: Schifitto
authors.forename: Leena M
authors.initials: LM
authors.lastname: Ketonen
authors.forename: Dieter J
authors.initials: DJ
authors.lastname: Meyerhoff
authors.forename: Robert E
authors.initials: RE
authors.lastname: Lenkinski
authors.forename: R Gilberto
authors.initials: RG
authors.lastname: Gonzalez
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Navia
mesh_terms: D015526:AIDS Dementia Complex / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage; D005240:Feasibility Studies; D006801:Humans; D006859:Hydrogen; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008559:Memantine / Q000008:administration & dosage; D009457:Neuroglia / Q000378:metabolism; D019047:Phantoms, Imaging; D015203:Reproducibility of Results
chemical_list: D018691:Excitatory Amino Acid Antagonists; D001224:Aspartic Acid; D007294:Inositol; D006859:Hydrogen; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline; D008559:Memantine