title: Glycosaminoglycan chemical exchange saturation transfer in human lumbar intervertebral discs: Effect of saturation pulse and relationship with low back pain.
abstract: To evaluate the dependence of saturation pulse power and duration on glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging and assess the degeneration of human lumbar intervertebral discs (IVDs) using this method.
  
  
  
  All images were acquired on a 3T magnetic resonance imaging (MRI) scanner. The CEST effects were measured in the glycosaminoglycan (GAG) phantoms with different concentrations. In the human study, CEST effects were measured in the nucleus pulposus of IVD. We compared the CEST effects among the different saturation pulse powers (0.4, 0.8, and 1.6 μT) or durations (0.5, 1.0, and 2.0 sec) at each Pfirrmann grade (I-V). The relationship between the CEST effects and low back pain was also evaluated.
  
  
  
  The phantom study showed high correlations between the CEST effects and GAG concentration (R2= 0.863, P < 0.0001, linear regression). In the human study, the CEST effect obtained with the 0.8 μT power was significantly greater than those obtained with 0.4 (P < 0.01) and 1.6 μT power (P < 0.05) at Pfirrmann grade I. The CEST effect obtained with a 1.0-sec duration was significantly greater than those derived with 0.5 and 2.0 sec (P < 0.01) durations at Pfirrmann grades I and II. The CEST effects in the group with moderate low back pain were significantly lower than those in the groups without pain (P < 0.001) and with mild pain (P = 0.0216).
  
  
  
  The contrast of gagCEST imaging in the lumbar IVDs varied with saturation pulse power and duration. GagCEST imaging may serve as a tool for evaluating IVD degeneration in the lumbar spine.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:863-871.
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Tatsuhiro
authors.initials: T
authors.lastname: Wada
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Togao
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Tokunaga
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Funatsu
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism*; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D057054:Molecular Imaging / Q000379:methods; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D015415:Biomarkers; D006025:Glycosaminoglycans
keywords: back pain; chemical exchange saturation transfer; degeneration; glycosaminoglycan; intervertebral disc; saturation pulse