Introduction: Recent work has focused on characterizing MRI findings predictive of outcome in surgical management of cervical spondylosis. To date, however, agreement in measuring these markers remains unknown. We aim to evaluate interobserver agreement for MRI markers cited to predict outcome in treatment of cervical degenerative conditions.
Methods: A secondary analysis of cervical MRI images was performed among patients who underwent elective cervical spine surgery. Two neuroradiologists independently reviewed MRIs for: presence/absence and length of spinal cord signal change, the intervertebral level of worst compression, measurements of AP and lateral spinal cord diameter in the axial plane, AP measurements in the mid-sagittal plane, and presence/absence of kyphotic deformity. Interobserver reliability was compared using kappa for dichotomous variables were agreement was defined as poor (K=0.00-0.20), fair (K=0.21-0.40), moderate (K=0.41-0.60), good (K=0.61-0.80), or very good (K>0.80). Interclass correlation coefficient was used to evaluate reliability for continuous variables.
Results: Markers were measured in 209 patients (N=209). Reliability was fair for cord signal change on T1- (K=0.33, 95% CI 0.04-0.62) and good for T2- (K=0.74, 95% CI 0.62-0.86) weighted images. For patients with signal change on T2 (N=22) reliability of signal change length was good (ICC=0.67, 95% CI 0.36-0.85). Reliability was good (K=0.79, 95% CI 0.72-0.87) in identification of level of worst compression. For AP cord diameter reliability was very good (ICC=0.82, 95% CI 0.77-0.86; T2-/mid-sagittal plane) and good (ICC=0.66, 95% CI 0.57-0.73; T2-/axial plane). Reliability in measurement of lateral cord diameter was moderate (ICC=0.55; 95% CI 0.44-0.64; T2-/axial plane) and good for kyphotic deformity (K=0.76, 95% CI 0.67-0.85).
Conclusions: The good and very good reliability observed in measuring T2-weighted spinal cord signal change, length of T2 signal change, level of worst cord compression, AP cord diameter, and kyphosis support the use of these markers in standardized reporting practices.
Patient Care: Given the lack of standardized reporting practices for measuring the multiple MRI characteristics in cervical spine degenerative conditions, efforts may be focused on establishing routine citation of markers with good and very good reliability.
Learning Objectives: At the conclusion of this session, participants should be able to:
1) Describe the MRI markers cited to be predictive of surgical outcome in cervical degenerative disease
2) Identify which markers exhibit the greatest interobserver reliability
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