title: Clinical severity of Alzheimer's disease is associated with PIB uptake in PET.
abstract: BACKGROUND
  The positron emission tomography (PET) tracer [11C]-Pittsburgh Compound-B ([11C]PIB) allows the in vivo assessment of amyloid plaque burden in the brain. In a cross-sectional study we examined the association between the severity of dementia assessed using the Clinical Dementia Rating scale sum of boxes (CDR-SOB) and [11C]PIB-PET in patients with Alzheimer's disease (AD).
  
  
  METHODS
  Patients with probable AD who had an AD-typical [18F]FDG-PET scan were included. Linear regression analysis in anatomically defined regions-of-interest (ROIs) and correlation analysis using statistical parametric mapping (SPM) were used to determine the association between CDR-SOB and [11C]PIB uptake.
  
  
  RESULTS
  The linear regression analyses showed that the CDR-SOB explained approximately 11-22% of the variance of [11C]PIB uptake. The association attained statistical significance in both frontal, in both anterior cingulate cortices, and in both putamina. The SPM analysis showed a significant association in more widespread regions of the brain, with maxima located in similar areas as in the ROI-analysis.
  
  
  CONCLUSIONS
  The CDR-SOB score is significantly associated with [11C]PIB uptake in patients with AD. Thus [11C]PIB is a potential surrogate marker of dementia severity.
authors.affiliation: Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, 81675 Munich, Germany. t.grimmer@lrz.tum.de
authors.forename: Timo
authors.initials: T
authors.lastname: Grimmer
authors.forename: Gjermund
authors.initials: G
authors.lastname: Henriksen
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Wester
authors.forename: Hans
authors.initials: H
authors.lastname: Förstl
authors.forename: William E
authors.initials: WE
authors.lastname: Klunk
authors.forename: Chester A
authors.initials: CA
authors.lastname: Mathis
authors.forename: Alexander
authors.initials: A
authors.lastname: Kurz
authors.forename: Alexander
authors.initials: A
authors.lastname: Drzezga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D000814:Aniline Compounds; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000814:Aniline Compounds; D013844:Thiazoles