TABLE 2.

Grading of Lumbar Spinal Canal Stenosis According to Magnetic Resonance Imaging Parameters

Magnetic Resonance Parameters	Grade	Description
Compromise of central zone	Mild	Compromise of ≤1/3 of its normal size
	Moderate	Compromise of 1/3–2/3 of its normal size
	Severe	Compromise of >2/3 of its normal size
Relation between fluid and cauda equina (Schizas classification)	Mild	The nerve rootlets lie dorsally or centrally; CSF is well visible in the dorsal sac
	Moderate	The nerve rootlets occupy the whole of the dural sac; some CSF is still present
	Severe	No nerve rootlets visible; no CSF visible
Nerve root compression in the lateral recesses	Mild	Lateral recess narrowing; no nerve root compression
	Moderate	More significant lateral recess narrowing; nerve root compression with CSF around
	Severe	Severe nerve root compression without CSF around

CSF indicates cerebrospinal fluid.