title: Determining disk hydration status with a MnCl2-based MR model.
abstract: OBJECTIVE
  An extensive body of literature demonstrates a strong correlation between intervertebral disk (IVD) hydration status (HS) and functional spinal integrity. However, to date, in vivo IVD HS assessment has relied largely on subjective and nonrepeatable measures. The aim of this study was to establish the consistency of signal homogeneity of a novel semisolid-state manganese chloride (MnCl2)-based phantom for HS correlation using conventional magnetic resonance (MR) imaging.
  
  
  METHODS
  Sixteen MnCl2 phantoms, of increasing relative molar concentration (range 0.01 to 2.9 mM), underwent axial MR imaging. Phantom signal-to-noise ratio measures were recorded for each concentration on several sequence types. Coefficient of variance data were calculated to determine the degree of MR signal variation at each concentration.
  
  
  RESULTS
  Analysis of variance testing suggested no significant difference in coefficient of variance data derived from phantom signal intensities using either T1- (P = .13) or T2-weighted sequence types (P = .96), suggesting a high degree of relative signal homogeneity.
  
  
  CONCLUSIONS
  The findings of this study suggest that a MnCl2 phantom combined with a nonfield reactive, semirigid, gelatin suspension media can produce a predictable, concentration-related, homogeneous MR signal response. This may be an appropriate base material for a noninvasive model to allow accurate quantification of the hydration status of the in vivo human IVD.
authors.affiliation: Bone and Joint Research Laboratory, IMVS/Hanson Institute in Adelaide, South Australia.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Kurmis
authors.forename: John P
authors.initials: JP
authors.lastname: Slavotinek
authors.forename: Christine
authors.initials: C
authors.lastname: Barber
authors.forename: Nicola L
authors.initials: NL
authors.lastname: Fazzalari
mesh_terms: D001834:Body Water / Q000378:metabolism*; D002712:Chlorides; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D017895:Manganese Compounds; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002712:Chlorides; D017895:Manganese Compounds; C025340:manganese chloride