title: Reliability of quantitative magnetic resonance imaging methods in the assessment of spinal canal stenosis and cord compression in cervical myelopathy.
abstract: METHODS
  Prospective, blinded reliability study of quantitative magnetic resonance imaging (MRI) measures in patients with cervical myelopathy.
  
  
  OBJECTIVE
  To assess the intra- and interobserver reliability of commonly used quantitative MRI measures such as transverse area (TA) of spinal cord, compression ratio (CR), maximum canal compromise (MCC), and maximum spinal cord compression (MSCC).
  
  
  BACKGROUND
  There is no consensus on an optimal quantitative MRI method(s) in assessing canal stenosis and cord compression.
  
  
  METHODS
  Seven surgeons performed measurements on 17 digital MR images, on 4 separate occasions. The degree of stenosis was evaluated by measuring TA and CR on axial T2, MCC, and MSCC on midsagittal T1- and T2-weighted MRI sequences, respectively. Statistical analyses included repeated-measures analysis of variance and intraclass correlation coefficients (ICCs).
  
  
  RESULTS
  The mean ± SD for intraobserver ICC was 0.88 ± 0.1 for MCC, 0.76 ± 0.08 for MSCC, 0.92 ± 0.07 for TA, and 0.82 ± 0.13 for CR. In addition, the interobserver ICC was 0.75 ± 0.04 for MCC, 0.79 ± 0.09 for MSCC, 0.80 ± 0.05 for CR, and 0.86 ± 0.03 for TA. Higher degree of canal compromise (MCC) was associated with lower modified version of Japanese Orthopaedic Association Scale score (P = 0.05). Also, a strong association was found between MSCC and lower modified version of Japanese Orthopaedic Association Scale score, greater number of steps, and longer walking time (P < 0.05).
  
  
  CONCLUSIONS
  All 4 measurement techniques demonstrated a good to moderately high degree of intra- and interobserver reliability. Highest reliability was noted in the assessment of T2-weighted sequences and axial MRI. Our results show that the measurements of MCC, MSCC, and CR are sufficiently reliable and correlate well with clinical severity of cervical myelopathy.
authors: Division of Neurosurgery, University of Toronto, Toronto, Canada.
authors: Alina
authors: A
authors: Karpova
authors: Ranganathan
authors: R
authors: Arun
authors: Aileen M
authors: AM
authors: Davis
authors: Abhaya V
authors: AV
authors: Kulkarni
authors: David J
authors: DJ
authors: Mikulis
authors: Chua
authors: C
authors: Sooyong
authors: Doron
authors: D
authors: Rabin
authors: Sorin
authors: S
authors: Craciunas
authors: Sean R
authors: SR
authors: Smith
authors: Mitchell A
authors: MA
authors: Hansen
authors: Joshi
authors: J
authors: George
authors: Michael G
authors: MG
authors: Fehlings
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011859:Radiography; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity; D013115:Spinal Canal / Q000000981:diagnostic imaging / Q000473:pathology; D013117:Spinal Cord Compression / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013130:Spinal Stenosis / Q000175:diagnosis / Q000000981:diagnostic imaging*