Spinal Canal Stenosis Measurements (Cervical / Lumbar) — free guideline decision tool
Cervical: canal AP diameter and Torg-Pavlov ratio. Lumbar: canal AP diameter, dural sac cross-sectional area, lateral recess and foraminal height, graded absolute / relative stenosis. Includes how to measure and what each value means. Instant, browser-side.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
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.
| Region | Cervical |
|---|---|
| Vertebral body AP diameter (Torg-Pavlov) | 17 mm |
| Cervical canal AP diameter | 12 mm |
→Cervical canal AP diameter12mm
- Cervical canal AP diameter：12 mm → 10–13 mm: relative stenosis
- Torg-Pavlov ratio：0.71 → < 0.8: developmental cervical stenosis
| Region | Lumbar |
|---|---|
| Lumbar canal AP diameter | 11 mm |
| Dural sac CSA | 85 mm² |
| Lateral recess height | 3 mm |
| Foraminal height | 16 mm |
→Lumbar canal AP diameter11mm
- Lumbar canal AP diameter：11 mm → 10–12 mm: relative stenosis
- Dural sac CSA：85 mm² → 75–100 mm²: relative stenosis
- Lateral recess height：3 mm → ≥ 3 mm: normal
Common questions
What is Spinal Canal Stenosis Measurements (Cervical / Lumbar)?
Cervical: canal AP diameter and Torg-Pavlov ratio. Lumbar: canal AP diameter, dural sac cross-sectional area, lateral recess and foraminal height, graded absolute / relative stenosis. Includes how to measure and what each value means. Instant, browser-side.
How is Spinal Canal Stenosis Measurements (Cervical / Lumbar) calculated? What is the core formula?
Cervical canal AP diameter < 10 mm: absolute stenosis (high cord-compression risk) Cervical canal AP diameter 10–13 mm: relative stenosis Cervical canal AP diameter ≥ 13 mm: normal Torg-Pavlov ratio < 0.8: developmental cervical stenosis Torg-Pavlov ratio ≥ 0.8: normal Lumbar canal AP diameter < 10 mm: absolute stenosis Lumbar canal AP diameter 10–12 mm: relative stenosis Lumbar canal AP diameter ≥ 12 mm: normal Dural sac CSA < 75 mm²: absolute stenosis Dural sac CSA 75–100 mm²: relative stenosis Dural sac CSA ≥ 100 mm²: normal Lateral recess height < 3 mm: lateral recess stenosis Lateral recess height ≥ 3 mm: normal Foraminal height < 15 mm: possible foraminal stenosis (more likely if posterior disc height < 4 mm) Foraminal height ≥ 15 mm: normal
When is Spinal Canal Stenosis Measurements (Cervical / Lumbar) used?
Spine imaging: standing full-spine films, flexion/extension views, CT/MRI — scoliosis follow-up, adult deformity, stenosis reporting and surgical planning.
What are the key clinical points for Spinal Canal Stenosis Measurements (Cervical / Lumbar)?
Lateral cervical radiograph: canal AP diameter from the mid posterior vertebral body to the spinolaminar line; divided by the vertebral body AP diameter gives the Torg-Pavlov ratio (magnification-independent). Each value is graded against published reference ranges. Measurement technique and positioning change the numbers — compare like with like on follow-up. Part of the YuanDoctor MSK measurement topic.
What are the limits and cautions when using Spinal Canal Stenosis Measurements (Cervical / Lumbar)?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does Spinal Canal Stenosis Measurements (Cervical / Lumbar) 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 Spinal Canal Stenosis Measurements (Cervical / Lumbar) calculated in practice? Can you show a worked example?
Inputs: Region Cervical, Vertebral body AP diameter (Torg-Pavlov) 17 mm, Cervical canal AP diameter 12 mm → Result: Cervical canal AP diameter 12 mm（Cervical canal AP diameter: 12 mm → 10–13 mm: relative stenosis, Torg-Pavlov ratio: 0.71 → < 0.8: developmental cervical stenosis） Inputs: Region Lumbar, Lumbar canal AP diameter 11 mm, Dural sac CSA 85 mm², Lateral recess height 3 mm, Foraminal height 16 mm → Result: Lumbar canal AP diameter 11 mm（Lumbar canal AP diameter: 11 mm → 10–12 mm: relative stenosis, Dural sac CSA: 85 mm² → 75–100 mm²: relative stenosis, Lateral recess height: 3 mm → ≥ 3 mm: normal）
Run Spinal Canal Stenosis Measurements (Cervical / Lumbar) now
Cervical: canal AP diameter and Torg-Pavlov ratio. Lumbar: canal AP diameter, dural sac cross-sectional area, lateral recess and foraminal height, graded absolute / relative stenosis. Includes how to measure and what each value means. Instant, browser-side.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.