Radiologic Assessment of Cervical Canal Stenosis Using Kang MRI Grading System: Do Clinical Symptoms Correlate with Imaging Findings?

Introduction Magnetic resonance imaging (MRI) is widely used in the evaluation of cervical canal stenosis and spinal cord compression. Kang et al. formulated a new MRI grading system for assessing canal stenosis which takes cord signal change into account. The purpose of the study was to determine the agreement between Kang's grading system and neurological symptoms. Methods  A cross-sectional study was conducted at Aga Khan University Hospital between April 2014 and December 2015. Patients meeting inclusion criteria were enrolled. T2 sagittal and T2 axial MRI images were acquired and reported by a consultant neuroradiologist, in accordance with the MRI grading system suggested by Kang et al. Neurologic clinical symptoms were acquired by the history taken by the principal investigator. More than one neurologic symptoms and Kang MRI grade 2 or 3 were taken as positive evidence of cord compression resulting from canal stenosis. Results Amongst 126 subjects, 54% were females. Mean age of patients was 50.3 ± 14.3 years (range 19-83 years). Average disease duration was 4.61 ± 3.73 (range 1-24 months). In the majority of the patients, the findings were found at the C5-C6 level. 65.1% of patients were identified positive for cervical canal stenosis by Kang grading system. Most common neurological symptoms were pain (99%) and numbness (56%). Cohen's Kappa was run to evaluate the agreement between neurological symptoms and Kang grading system. There was a strong agreement between the two methods, K = 0.81 (95% CI 0.70-0.92), p < 0.001. Conclusion There was a substantial agreement between Kang's grading system and the presence of clinical symptoms. The agreement was greatest in females, older patients, and those with longer duration of symptoms.