Degenerative findings on MRI of the cervical spine: an inter- and intra-rater reliability study.

Background: Knowledge about the assessment reliability of common cervical spine changes is a prerequisite for precise and consistent communication about Magnetic Resonance Imaging (MRI) findings. The purpose of this study was to determine the inter- and intra-rater reliability of degenerative findings when assessing cervical spine MRI. Methods: Fifty cervical spine MRIs from subjects with neck pain were used. A radiologist, a chiropractor and a second-year resident of rheumatology independently assessed kyphosis, disc height, disc contour, vertebral endplate signal changes, spinal canal stenosis, neural foraminal stenosis, and osteoarthritis of the uncovertebral and zygapophyseal joints. An evaluation manual was composed containing classifications and illustrative examples, and ten of the MRIs were evaluated twice followed by consensus meetings to refine the classifications. Next, the three readers independently assessed the full sample. Reliability measures were reported using prevalence estimates and unweighted kappa (Κ) statistics. Results: The overall inter-rater reliability was substantial (Κ ≥ 0.61) for the majority of variables and moderate only for zygapophyseal osteoarthritis (Κ = 0.56). Intra-rater reliability estimates were higher for all findings. Conclusions: The present classifications for some of the most common cervical degenerative findings yielded mainly substantial inter-rater reliability estimates and substantial to almost perfect intra-rater reliability estimates. . Trial registration: Regional Data Protection Agency (J.no. 1-16-02-86-16). The letter of exemption from the Regional Ethical Committee is available from the author on request (case no. 86 / 2017).