title: Quantitative T2 evaluation at 3.0T compared to morphological grading of the lumbar intervertebral disc: a standardized evaluation approach in patients with low back pain.
abstract: BACKGROUND
  The purpose of our investigation was to compare quantitative T2 relaxation time measurement evaluation of lumbar intervertebral discs with morphological grading in young to middle-aged patients with low back pain, using a standardized region-of-interest evaluation approach.
  
  
  METHODS
  Three hundred thirty lumbar discs from 66 patients (mean age, 39 years) with low back pain were examined on a 3.0T MR unit. Sagittal T1-FSE, sagittal, coronal, and axial T2-weighted FSE for morphological MRI, as well as a multi-echo spin-echo sequence for T2 mapping, were performed. Morphologically, all discs were classified according to Pfirrmann et al. Equally sized rectangular regions of interest (ROIs) for the annulus fibrosus were selected anteriorly and posteriorly in the outermost 20% of the disc. The space between was defined as the nucleus pulposus. To assess the reproducibility of this evaluation, inter- and intraobserver statistics were performed.
  
  
  RESULTS
  The Pfirrmann scoring of 330 discs showed the following results: grade I: six discs (1.8%); grade II: 189 (57.3%); grade III: 96 (29.1%); grade IV: 38 (11.5%); and grade V: one (0.3%). The mean T2 values (in milliseconds) for the anterior and the posterior annulus, and the nucleus pulposus for the respective Pfirrmann groups were: I: 57/30/239; II: 44/67/129; III: 42/51/82; and IV: 42/44/56. The nucleus pulposus T2 values showed a stepwise decrease from Pfirrmann grade I to IV. The posterior annulus showed the highest T2 values in Pfirrmann group II, while the anterior annulus showed relatively constant T2 values in all Pfirrmann groups. The inter- and intraobserver analysis yielded intraclass correlation coefficients (ICC) for average measures in a range from 0.82 (anterior annulus) to 0.99 (nucleus).
  
  
  CONCLUSIONS
  Our standardized method of region-specific quantitative T2 relaxation time evaluation seems to be able to characterize different degrees of disc degeneration quantitatively. The reproducibility of our ROI measurements is sufficient to encourage the use of this method in future investigations, particularly for longitudinal studies.
authors.affiliation: Department of Radiology, MR Centre, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Stelzeneder
authors.forename: Goetz Hannes
authors.initials: GH
authors.lastname: Welsch
authors.forename: Balázs Krisztián
authors.initials: BK
authors.lastname: Kovács
authors.forename: Sabine
authors.initials: S
authors.lastname: Goed
authors.forename: Tatjana
authors.initials: T
authors.lastname: Paternostro-Sluga
authors.forename: Marianna
authors.initials: M
authors.lastname: Vlychou
authors.forename: Klaus
authors.initials: K
authors.lastname: Friedrich
authors.forename: Tallal Charles
authors.initials: TC
authors.lastname: Mamisch
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007403:Intervertebral Disc / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000150:complications* / Q000473:pathology*; D017116:Low Back Pain / Q000175:diagnosis* / Q000209:etiology*; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity