title: Comparison of glycosaminoglycan chemical exchange saturation transfer using Gaussian-shaped and off-resonant spin-lock radiofrequency pulses in intervertebral disks.
abstract: To investigate, if a train of spin-lock pulses (chemical exchange saturation transfer with spin-lock pulses = CESL) improves biochemical glycosaminoglycan imaging compared with conventional chemical exchange saturation transfer with Gaussian-shaped pulses (CEST) in lumbar intervertebral discs.
  
  
  
  T2, CEST, and CESL imaging was performed in lumbar intervertebral discs of 15 healthy volunteers at 3 Tesla. Mean and standard deviation of the asymmetric magnetization transfer ratio (MTRasym), the asymmetric spin-lock ratio (SLRasym) and T2values were calculated for nucleus pulposus (NP) and annulus fibrosus (AF). Wilcoxon test was used to analyze differences between MTRasymand SLRasym. Pearson correlation was used to determine the relationship between MTRasym, SLRasymand T2.
  
  
  
  Data showed no significant difference between MTRasymand SLRasym(NP: P = 0.35; AF: P = 0.34). MTRasymand SLRasymvalues differed significantly between NP and AF (MTRasym: P = 0.014, SLRasym: P = 0.005). T2values correlated significantly with MTRasym(NP: ρ = 0.76, P < 0.001; AF: ρ = 0.60, P < 0.001) and SLRasym(NP: ρ = 0.73, P < 0.001; AF: ρ = 0.47, P < 0.001).
  
  
  
  CESL does not improve the chemical exchange asymmetry effect compared with conventional CEST, but leads to comparable results. Magn Reson Med 78:280-284, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Müller-Lutz
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Cronenberg
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schleich
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Frithjof
authors.initials: F
authors.lastname: Wickrath
authors.affiliation: Department of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Zaiss
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Boos
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
mesh_terms: D000328:Adult; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015233:Models, Statistical; D057054:Molecular Imaging / Q000379:methods*; D016011:Normal Distribution; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels; D055815:Young Adult
chemical_list: D006025:Glycosaminoglycans; D013113:Spin Labels
keywords: chemical exchange saturation transfer; glycosaminoglycans; intervertebral disks; spin-lock