title: Gender, BMI and T2 dependencies of glycosaminoglycan chemical exchange saturation transfer in intervertebral discs.
abstract: OBJECTIVE
  The purpose was to investigate the dependence of glycosaminoglycan chemical exchange saturation transfer (gagCEST) effect of lumbar intervertebral discs (IVD) on gender, body mass index and T2 value.
  
  
  METHODS
  T2 imaging and gagCEST imaging was performed in 34 healthy volunteers (17 males, 17 females) without low back pain at a 3T MRI system (Magnetom Trio, A Tim System, Siemens Healthcare, Erlangen, Germany). The body mass index was determined for each volunteer. The mean and standard deviation of MTRasym and T2 values were calculated for nucleus pulposus (NP) and annulus fibrosus (AF) as descriptive statistics for females and males. An unpaired student's t-test was applied in order to validate obtained differences. Pearson correlation was determined in order to reveal, if gagCEST effect and T2 values decrease with increasing body mass index (BMI). Pearson correlation analysis was additionally performed between gagCEST and T2 values.
  
  
  RESULTS
  GagCEST effect and T2 values were significantly higher in females compared to males [gagCEST effect (nucleus pulposus, females)=3.58±1.49%; gagCEST effect (nucleus pulosus, males)=3.01±1.63%, p-value (gagCEST effect, nucleus pulposus)=0.02); T2 (nucleus pulposus, females)=134.56±30.27 ms, T2 (nucleus pulposus, males)=122.35±27.64 ms, p-value (T2, nucleus pulposus)=0.01)]. Pearson correlation analysis showed a significant negative relation between BMI and gagCEST effect (nucleus pulposus: ρ=-0.16, p=0.03) and between BMI and T2 values (nucleus pulposus: ρ=-0.30, p<0.01). The correlation between gagCEST effect and T2-values was highly significant (nucleus pulposus: ρ=0.59, p<0.01).
  
  
  CONCLUSIONS
  Significantly lower gagCEST effects were found in males compared to females and with increased body mass index. The gagCEST effect was highly correlated with quantitative T2 imaging.
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Müller-Lutz
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany. Electronic address: Christoph.Schleich@med.uni-duesseldorf.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schleich
authors.affiliation: Siemens Ltd. Australia, Healthcare Sector, 160 Herring Road, Macquarie Park NSW 2113, Australia.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schmitt
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Matuschke
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Quentin
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Miese
mesh_terms: D000328:Adult; D000070616:Annulus Fibrosus / Q000000981:diagnostic imaging; D015992:Body Mass Index; D005260:Female; D006025:Glycosaminoglycans / Q000737:chemistry*; D064368:Healthy Volunteers; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D000070614:Nucleus Pulposus / Q000000981:diagnostic imaging; D012737:Sex Factors; D055815:Young Adult
chemical_list: D006025:Glycosaminoglycans
keywords: Body mass index; Chemical exchange saturation transfer (CEST); Gender; Glycosaminoglycan content; Intervertebral disc; T2 value