title: Evaluation of the posterior cingulate region with FDG-PET and advanced MR techniques in patients with amnestic mild cognitive impairment: comparison of the methods.
abstract: BACKGROUND
  The posterior cingulate region is an area of the earliest pathological changes in amnestic mild cognitive impairment (aMCI). The utility of FDG-PET imaging in dementia is already well established.
  
  
  OBJECTIVE
  The aim of the study was to compare FDG-PET with advanced MR measurements: MR spectroscopy (MRS), perfusion weighted imaging (PWI), and diffusion tensor imaging (DTI) within the posterior cingulate region in patients with aMCI.
  
  
  METHODS
  Fifty-five patients diagnosed with aMCI (66.5 y) and 20 age-matched controls (69 y) underwent MR examination including MRS, PWI, and DTI followed by FDG-PET scanning. Values of MRS metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr), PWI cerebral blood volume (rCBV), and DTI fractional anisotropy (FA) were compared to the FDG-PET rates of glucose metabolism.
  
  
  RESULTS
  Compared to controls, aMCI patients showed significant (p < 0.05) glucose hypometabolism, and lower rCBV and FA values. FDG-PET results correlated significantly with rCBV values. Compared to FDG-PET, PWI showed similar and DTI greater accuracy in distinguishing aMCI from controls. According to FDG-PET findings, two groups of aMCI patients were established: those with lower (PET-positive) and normal (PET-negative) glucose uptake. PET-positive aMCI subjects showed normal MRS findings, lower rCBV and FA values, while PET-negative patients revealed normal MRS and PWI results but significantly lower FA values.
  
  
  CONCLUSIONS
  Advanced MR techniques such as PWI and particularly DTI may be regarded as competitive techniques to FDG-PET. DTI was the only method to show alterations in aMCI patients with normal FDG-PET, PWI, and MRS findings. DTI seems to be a very sensitive biomarker of early degeneration in aMCI.
authors.affiliation: Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Zimny
authors.affiliation: Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Bladowska
authors.affiliation: Department of Nuclear Medicine, 4th Military Hospital, Wroclaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Macioszek
authors.affiliation: Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Szewczyk
authors.affiliation: Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Trypka
authors.affiliation: Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Wojtynska
authors.affiliation: Department of Pathophysiology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Noga
authors.affiliation: Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Leszek
authors.affiliation: Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland Euromedic Wroclaw PET/CT Medical Center, Wroclaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Sasiadek
mesh_terms: D000368:Aged; D000647:Amnesia / Q000150:complications; D016880:Anisotropy; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000209:etiology / Q000473:pathology*; D003952:Diagnostic Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging; D049268:Positron-Emission Tomography; D012044:Regression Analysis; D012189:Retrospective Studies
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Amnestic mild cognitive impairment; diffusion tensor imaging; glucose metabolism; magnetic resonance spectroscopy; perfusion weighted imaging; positron emission tomography; posterior cingulate gyrus