title: Lumbar intervertebral discs T2 relaxometry and T1ρ relaxometry correlation with age in asymptomatic young adults.
abstract: BACKGROUND
  To investigate the detection of intervertebral disc (IVD) composition aging-related changes using T2 and T1ρ relaxometry in vivo in asymptomatic young adults.
  
  
  METHODS
  We recruited ninety asymptomatic and young adults (42 men and 48 women) between 20 and 40 years old. T2 and T1ρ lumbar spine mappings were acquired using 1.5 T magnetic resonance imaging (MRI) scanner. Two independent observers manually segmented 450 lumbar discs in all slices. They also performed sub region segmentation of annulus fibrosus (AF) and nucleus pulposus (NP) at the central MRI sagittal slices.
  
  
  RESULTS
  There was no difference between men and women for T2 (P=0.37) or T1ρ relaxometry (P=0.97). There was a negative correlation between age (20-40 years) and IVD T2 relaxation time of the whole disc (r=-0.30, P<0.0001), NP (r=-0.20 to -0.51, P<0.05) and posterior AF (r=-0.21 to -0.31, P<0.05) at all lumbar disc levels. There was no statistical correlation between aging and IVD T1ρ relaxation both for NP and AF.
  
  
  CONCLUSIONS
  T2 relaxometry detected gradual IVD dehydration in the first two decades of adulthood. We observed no significant variation of T1ρ or volumetry with aging in our study group. Our results suggest that T2 mapping may be more appropriate to detect early IVD aging changes.
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Menezes-Reis
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil;; Department of Physics, Ribeirão Preto School of Philosophy and Sciences, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Carlos E Garrido
authors.initials: CE
authors.lastname: Salmon
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil.
authors.forename: Gustavo P
authors.initials: GP
authors.lastname: Bonugli
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil.
authors.forename: Debora
authors.initials: D
authors.lastname: Mazoroski
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil.
authors.forename: Mauricio H
authors.initials: MH
authors.lastname: Tamashiro
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil.
authors.forename: Leonor G
authors.initials: LG
authors.lastname: Savarese
authors.affiliation: Laboratory of informatics in radiology (LAPIR), Ribeirão Preto Medical School, Ribeirão Preto, Brazil;; Division of Radiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Marcello Henrique
authors.initials: MH
authors.lastname: Nogueira-Barbosa
keywords: Intervertebral disc (IVD) degeneration; aging; lumbosacral region; magnetic resonance imaging (MRI); spine