title: The limbic degradation of aging brain: a quantitative analysis with diffusion tensor imaging.
abstract: BACKGROUND
  The limbic system primarily responsible for our emotional life and memories is known to undergo degradation with aging and diffusion tensor imaging (DTI) is capable of revealing the white matter integrity. The aim of this study is to investigate age-related changes of quantitative diffusivity parameters and fiber characteristics on limbic system in healthy volunteers.
  
  
  METHODS
  31 healthy subjects aged 25-70 years were examined at 1,5 TMR. Quantitative fiber tracking was performed of fornix, cingulum, and the parahippocampal gyrus. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) measurements of bilateral hippocampus, amygdala, fornix, cingulum, and parahippocampal gyrus were obtained as related components.
  
  
  RESULTS
  The FA values of left hippocampus, bilateral parahippocampal gyrus, and fornix showed negative correlations with aging. The ADC values of right amygdala and left cingulum interestingly showed negative relation and the left hippocampus represented positive relation with age. The cingulum showed no correlation. The significant relative changes per decade of age were found in the cingulum and parahippocampal gyrus FA measurements.
  
  
  CONCLUSIONS
  Our approach shows that aging affects hippocampus, parahippocampus, and fornix significantly but not cingulum. These findings reveal age-related changes of limbic system in normal population that may contribute to future DTI studies.
authors: Radiology Department, Ondokuz Mayıs University, Kurupelit, 55139 Samsun, Turkey.
authors: Hediye Pınar
authors: HP
authors: Gunbey
authors: Radiology Department, Ataturk Research and Education Hospital, Ankara, Turkey.
authors: Karabekir
authors: K
authors: Ercan
authors: Radiology Department, Medipol University Hospital, Istanbul, Turkey.
authors: Ayşe Serap
authors: AS
authors: Fındıkoglu
authors: Radiology Department, Adıyaman University, Adıyaman, Turkey.
authors: H Taner
authors: HT
authors: Bulut
authors: Radiology Department, Ataturk Research and Education Hospital, Ankara, Turkey.
authors: Mustafa
authors: M
authors: Karaoglanoglu
authors: Radiology Department, Ataturk Research and Education Hospital, Ankara, Turkey.
authors: Halil
authors: H
authors: Arslan
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008032:Limbic System / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology*