🦴 Schizas Grading of Lumbar Spinal Stenosis on MRI (A1–A4 / B / C / D)
UseDescribing central canal stenosis in lumbar MRI reports, aligning terminology in clinic and pre-operative mee…
Grade diagrams (axial T2 schematic; ventral up, dorsal down)
CSF (bright)RootletsEpidural fat· Schematic, not a real image
StrataA: no or minor stenosis; B: moderate; C: severe; D: extreme. In the original study C and D grades failed cons…
LimitsMorphological grading does not replace clinical assessment, nor quant… · Central canal only; describe lateral recess and foraminal stenosis se… · Grading relies on a single axial T2 slice; choose the narrowest level…
SourceSchizas C, Theumann N, Burn A, et al. Qualitative grading of severity of lumbar spinal stenosis bas…
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
Methodology · worked example, guidelines & full notes
Three looks: CSF, rootlet separability, posterior epidural fat.
When to use
Describing central canal stenosis in lumbar MRI reports, aligning terminology in clinic and pre-operative meetings, and comparing follow-up scans. Central canal only; lateral recess and foramina are graded separately.
How it works
Step 1: is CSF signal present in the dural sac? Yes → Step 2: do rootlets fill the whole sac? No → grade A, subtype by rootlet position: A1 (dorsal, <1/2), A2 (dorsal, horseshoe against dura), A3 (dorsal, >1/2), A4 (central, majority). Yes but still individualised → grade B. No → Step 3: is posterior epidural fat present? Present → grade C; absent → grade D.
Key points
- Three looks: CSF, rootlet separability, posterior epidural fat.
- CSF present: A (not filling, A1–A4) or B (filling but separable).
- No CSF: C (posterior fat kept) or D (posterior fat gone).
- C/D fail conservative care more often, but grade is not a surgical indication.
References
- Schizas C, Theumann N, Burn A, et al. Qualitative grading of severity of lumbar spinal stenosis based on the morphology of the dural sac on magnetic resonance images. Spine (Phila Pa 1976). 2010;35(21):1919-1924. PMID 20671589
- Weber C, Rao V, Gulati S, et al. Inter- and intraobserver agreement of morphological grading for central lumbar spinal stenosis on MRI. Global Spine J. 2015;5(5):406-410. PMID 26430595
- Lønne G, Ødegård B, Johnsen LG, et al. MRI evaluation of lumbar spinal stenosis: is a rapid visual assessment as good as area measurement? Eur Spine J. 2014;23(6):1320-1324. PMID 24573778
- Ko YJ, Lee E, Lee JW, et al. Clinical validity of two different grading systems for lumbar central canal stenosis: Schizas and Lee classification systems. PLoS One. 2020;15(5):e0233633. PMID 32459814
- Mannion AF, Fekete TF, Pacifico D, et al. Dural sac cross-sectional area and morphological grade show significant associations with patient-rated outcome of surgery for lumbar central spinal stenosis. Eur Spine J. 2017;26(10):2552-2564. PMID 28856447
- Weber C, Giannadakis C, Rao V, et al. Is there an association between radiological severity of lumbar spinal stenosis and disability, pain, or surgical outcome? A multicenter observational study. Spine (Phila Pa 1976). 2016;41(2):E78-E83. PMID 26352747
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Level (optional, for the report sentence) | L3/4 |
|---|---|
| ① Is CSF (T2 bright signal) visible in the dural sac? | Visible — CSF signal still present |
| ② Do the rootlets fill the whole dural sac? (answer if ① = visible) | Not filling — CSF clearly visible, inhomogeneous distribution |
| ③ Grade A subtype: rootlet position (answer if ② = not filling) | A2 — rootlets lie dorsally, in contact with the dura, horseshoe configuration |
| ④ Is posterior epidural fat still present? (answer if ① = not visible) | Present — posterior epidural fat visible |
→Grade · No or minor stenosisSchizas A2
- Severity：No or minor stenosis
- Definition：Rootlets lie dorsally, in contact with the dura but in a horseshoe configuration; CSF clearly visible but inhomogeneously distributed.
- Path：CSF visible → rootlets not filling → rootlet position
| Level (optional, for the report sentence) | L1/2 |
|---|---|
| ① Is CSF (T2 bright signal) visible in the dural sac? | Visible — CSF signal still present |
| ② Do the rootlets fill the whole dural sac? (answer if ① = visible) | Not filling — CSF clearly visible, inhomogeneous distribution |
| ③ Grade A subtype: rootlet position (answer if ② = not filling) | A1 — rootlets lie dorsally, occupying less than half of the sac |
| ④ Is posterior epidural fat still present? (answer if ① = not visible) | Present — posterior epidural fat visible |
→Grade · No or minor stenosisSchizas A1
- Severity：No or minor stenosis
- Definition：Rootlets lie dorsally and occupy less than half of the dural sac area; CSF clearly visible but inhomogeneously distributed.
- Path：CSF visible → rootlets not filling → rootlet position
Verification & sources · governance
FAQ
Frequently asked questions
- Does Schizas Grading of Lumbar Spinal Stenosis on MRI (A1–A4 / B / C / D) upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is Schizas Grading of Lumbar Spinal Stenosis on MRI (A1–A4 / B / C / D) calculated in practice? Can you show a worked example?
- Inputs: Level (optional, for the report sentence) L3/4, ① Is CSF (T2 bright signal) visible in the dural sac? Visible — CSF signal still present, ② Do the rootlets fill the whole dural sac? (answer if ① = visible) Not filling — CSF clearly visible, inhomogeneous distribution, ③ Grade A subtype: rootlet position (answer if ② = not filling) A2 — rootlets lie dorsally, in contact with the dura, horseshoe configuration, ④ Is posterior epidural fat still present? (answer if ① = not visible) Present — posterior epidural fat visible → Result: Grade · No or minor stenosis Schizas A2（Severity: No or minor stenosis, Definition: Rootlets lie dorsally, in contact with the dura but in a horseshoe configuration; CSF clearly visible but inhomogeneously distributed., Path: CSF visible → rootlets not filling → rootlet position） Inputs: Level (optional, for the report sentence) L1/2, ① Is CSF (T2 bright signal) visible in the dural sac? Visible — CSF signal still present, ② Do the rootlets fill the whole dural sac? (answer if ① = visible) Not filling — CSF clearly visible, inhomogeneous distribution, ③ Grade A subtype: rootlet position (answer if ② = not filling) A1 — rootlets lie dorsally, occupying less than half of the sac, ④ Is posterior epidural fat still present? (answer if ① = not visible) Present — posterior epidural fat visible → Result: Grade · No or minor stenosis Schizas A1（Severity: No or minor stenosis, Definition: Rootlets lie dorsally and occupy less than half of the dural sac area; CSF clearly visible but inhomogeneously distributed., Path: CSF visible → rootlets not filling → rootlet position）