title: MR imaging assessment of lumbar intervertebral disk degeneration and age-related changes: apparent diffusion coefficient versus T2 quantitation.
abstract: OBJECTIVE
  T2 and ADC mappings are 2 quantitative MR imaging tools for assessing IVDD. This study aimed to compare these 2 measures in detecting IVDD and its age-related changes.
  
  
  METHODS
  Thirty-seven asymptomatic volunteers and 28 patients with back pain or sciatica were examined, and their lumbar disk T2 and ADC maps were quantified via sagittal imaging protocols at 1.5T. For all participants, the Pfirrmann system was used by 2 radiologists for grading disks. T2 and ADC values in the inner portion of disks were measured, and their variances in different grades were analyzed by 1-way ANOVA testing. The ability of T2 and ADC measures to differentiate IVDD grades was compared on the basis of their ROC curves. For asymptomatic subjects, the correlations between age and the 2 MR imaging measures were assessed by the Pearson correlation test.
  
  
  RESULTS
  Both T2 and ADC values were found to decrease with the increasing Pfirrmann grades except T2 in grade V. Significant T2 differences were seen among grades I-IV, but not between grades IV and V. There were no significant ADC differences among grades I-III. Moreover, the areas under the ROC curves differed significantly (0.95 and 0.67 for T2 and ADC, respectively). Linear regression analysis revealed that T2 yielded more significant correlation with age (r = -0.77) than ADC did (r = -0.37).
  
  
  CONCLUSIONS
  T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of IVDD and age-related disk changes.
authors.affiliation: Department of Diagnostic Radiology, First Hospital of Medical School, Xi’an Jiaotong University, Xi’an, China.
authors.forename: G
authors.initials: G
authors.lastname: Niu
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: R
authors.initials: R
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Dang
authors.forename: E X
authors.initials: EX
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000473:pathology*; D017116:Low Back Pain / Q000473:pathology; D008159:Lumbar Vertebrae / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D012585:Sciatica / Q000473:pathology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D055815:Young Adult