Date Posted: June 10, 2026

Author/s: Neil Michael D. Sese, MD and Ma. Theresa M. Bisquera, MD

Lumbar spinal canal stenosis is the compression of the central lumbar spinal canal caused by degenerative changes such reduction of the disc height with or without bulging of the intervertebral disc, hypertrophy of the ligamentum flavum, spurs and facet joints. The use of MRI plays a vital role in the diagnosis of lumbar central canal stenosis. There have been studies associating MRI grading with patient’s neurological impairment. However, there is still no standard diagnostic criteria or grading systems for spinal canal lumbar stenosis using MRI, causing discrepancies in the radiological reports with poor correlation in patients’ clinical symptoms. One promising study was made by Lee GY (2011) which proposes a novel classification of the lumbar spinal canal stenosis. The study suggested that primary cause of symptoms of the lumbar spinal canal stenosis is the encroachment of cauda equina nerve roots (with size of the spinal canal). With that, they made the classification according to cauda equina shape into four grades based on T2 weighted axial images. However, no local study or research was done to support this classification. The aim of this study was to evaluate the reproducibility of the Lee classification system in assessing lumbar spinal canal stenosis using the local population This retrospective study involved 50 years old and above patients who underwent lumbar magnetic resonance imaging. Lumbar MRI Axial T2 images of patients from 2018-2020 who met the inclusion criteria were reviewed by three radiologists. A teaching file created by the researcher explained the definition and criteria of the Lee system. These criteria were used by these radiologists in their grading of the obtained images. Interobserver agreement between the examining radiologists was analyzed for grading of lumbar spinal canal stenosis using the Fleiss’ kappa. ICC reliability was categorized as slight (0–0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80), and excellent (0.81–1.00). Using Fleiss’ kappa, average inter-observer agreements of per level in relation to the proposed grading classification were observed. The following are the averages per level: L3–4 with an average kappa of 0.5557; L4–5 with an average kappa of 0.7179; and L5–S1 with an average kappa of 0.5985. The total average kappa of all lumbar levels is 0.6240. With that, the inter-observer agreement in the grading of lumbar spinal canal stenosis among the three readers was substantial agreement.

Keywords:
Lumbar spinal cord stenosis, Lee’s classification system, Fleiss kappa