The Lee classification is used to grade lumbar Spinal canal stenoses into four grades based on axial T2-weighted sequences on MRI imaging and was published in 2011[^1].
Classification
Lee Grade | Description | Assessment |
Grade 0 | The anterior CSF space is not obliterated. | No stenosis |
Grade 1 | The anterior CSF space is mildly obliterated, but all Cauda equina fibers can be clearly distinguished from one another. | Mild stenosis |
Grade 2 | The anterior CSF space is moderately obliterated, and some of the cauda equina fibers are bundled together and cannot be visually distinguished. | Moderate stenosis |
Grade 3 | The CSF space is severely obliterated, such that marked compression of the dural sac is evident, and the cauda equina appears as a single bundle, with none of the bundles visually distinguishable from one another. | Severe stenosis |
