🔎 Spinal Canal Stenosis Measurements (Cervical / Lumbar)
UseSpine imaging: standing full-spine films, flexion/extension views, CT/MRI — scoliosis follow-up, adult deform…
SourcePavlov H, Torg JS, et al. Cervical spinal stenosis: determination with vertebral body ratio method.…
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
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).
When to use
Spine imaging: standing full-spine films, flexion/extension views, CT/MRI — scoliosis follow-up, adult deformity, stenosis reporting and surgical planning.
How it works
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
Key points
- 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.
References
- Pavlov H, Torg JS, et al. Cervical spinal stenosis: determination with vertebral body ratio method. Radiology 1987;164:771-775
- Verbiest H. The significance and principles of computerized axial tomography in idiopathic developmental stenosis of the bony lumbar vertebral canal. Spine 1979;4:369-378
- Hamanishi C, et al. Cross-sectional area of the stenotic lumbar dural tube measured from CT myelography. Spine 1994;19:2148-2152
- Hasegawa T, et al. Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. J Bone Joint Surg Am 1995;77:32-38
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
Verification & sources · governance
FAQ
Frequently asked questions
- 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）