title: Correlating quantitative MR imaging with histopathology in X-linked adrenoleukodystrophy.
abstract: OBJECTIVE
  Quantitative MR imaging techniques may improve the pathologic specificity of MR imaging regarding white matter abnormalities. Our purposes were to determine whether ADC, FA, MTR, and MRS metabolites correlate with the degree of white matter damage in patients with X-ALD; whether differences in ADC, FA, and MTR observed in vivo are retained in fresh and formalin-fixed postmortem brain tissue; and whether the differences predict histopathology.
  
  
  METHODS
  MRS metabolites, MTR, ADC, and FA, were determined in 7 patients with X-ALD in 3 white matter areas (NAWM, active demyelination, and complete demyelination) and were compared with values obtained in 14 controls. MTR, ADC, and FA were assessed in postmortem brains from 15 patients with X-ALD and 5 controls. Values were correlated with the degree of astrogliosis and density of myelin, axons, and cells. Equations to estimate histopathology from MR imaging parameters were calculated by linear regression analysis.
  
  
  RESULTS
  MRS showed increased mIns, Lac, and Cho and decreased tNAA in living patients with X-ALD; the values depended on the degree of demyelination. MTR, ADC, and FA values were different in postmortem than in vivo white matter, but differences related to degrees of white matter damage were retained. ADC was high and FA and MTR were low in abnormal white matter. Correlations between histopathologic findings and MR imaging parameters were strong. A combination of ADC and FA predicted pathologic parameters best.
  
  
  CONCLUSIONS
  Changes in quantitative MR imaging parameters, present in living patients and related to the severity of white matter pathology, are retained in postmortem brain tissue. MR imaging parameters predict white matter histopathologic parameters.
authors.affiliation: Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands. jp.vandervoorn@vumc.nl
authors.forename: J P
authors.initials: JP
authors.lastname: van der Voorn
authors.forename: P J W
authors.initials: PJ
authors.lastname: Pouwels
authors.forename: J M
authors.initials: JM
authors.lastname: Powers
authors.forename: W
authors.initials: W
authors.lastname: Kamphorst
authors.forename: J-J
authors.initials: JJ
authors.lastname: Martin
authors.forename: D
authors.initials: D
authors.lastname: Troost
authors.forename: M D
authors.initials: MD
authors.lastname: Spreeuwenberg
authors.forename: F
authors.initials: F
authors.lastname: Barkhof
authors.forename: M S
authors.initials: MS
authors.lastname: van der Knaap
mesh_terms: D000293:Adolescent; D000326:Adrenoleukodystrophy / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D055815:Young Adult