🧠 Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic)
This tool assesses rupture risk for ≤ 5 mm intracranial aneurysms using morphologic irregularity, aspect ratio, and size ratio, complementing PHASES.
Rupture risk should not be judged low by a diameter < 5 mm alone, since irregular morphology and high AR/SR strongly predict rupture (OR ~31/41/21). (original synthesis · not guideline verbatim)
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When to use
Use for small aneurysms where PHASES discriminates poorly, weighting the three strong morphologic predictors plus clinical modifiers.
How it works
Core: irregular morphology, AR (height/neck) ≥ 1.6, SR (height/parent-artery) ≥ 2. ≥ 2 core → higher risk; 1 → intermediate. Modifiers: hypertension, non-ICA location, smoking.
Key points
- Rupture risk should not be judged low by a diameter < 5 mm alone, since irregular morphology and high AR/SR strongly predict rupture (OR ~31/41/21). (original synthesis · not guideline verbatim)
- It is derived from Chinese-population studies as a complement to PHASES for small aneurysms.
- High-risk morphology favors active assessment/treatment or shorter follow-up with vessel-wall imaging.
References
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.
| Aneurysm height/depth | 4.0 mm |
|---|---|
| Neck width (for AR) | 2.5 mm |
| Parent-artery mean diameter (for SR) | 2.0 mm |
| Morphology | Regular |
| Hypertension | Absent |
| Location | ICA internal carotid artery |
| Smoking | Absent |
→Small-aneurysm rupture risk2 core high-risk · higher rupture risk
- Aspect ratio AR：1.60 (height/neck; ≥ 1.6 high-risk) ⚠ high
- Size ratio SR：2.00 (height/parent-artery diameter; ≥ 2 high-risk) ⚠ high
- Core high-risk features：aspect ratio AR ≥ 1.6, size ratio SR ≥ 2 (2 items)
| Aneurysm height/depth | 4.0 mm |
|---|---|
| Neck width (for AR) | 2.5 mm |
| Parent-artery mean diameter (for SR) | 2.0 mm |
| Morphology | Irregular (lobulated/daughter sac/bleb) |
| Hypertension | Present |
| Location | ACA/Pcom/posterior circulation |
| Smoking | Present |
→Small-aneurysm rupture risk3 core high-risk · higher rupture risk
- Aspect ratio AR：1.60 (height/neck; ≥ 1.6 high-risk) ⚠ high
- Size ratio SR：2.00 (height/parent-artery diameter; ≥ 2 high-risk) ⚠ high
- Core high-risk features：irregular morphology (lobulated/daughter sac), aspect ratio AR ≥ 1.6, size ratio SR ≥ 2 (3 items)
Frequently asked questions
- What is Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic)?
- This tool assesses rupture risk for ≤ 5 mm intracranial aneurysms using morphologic irregularity, aspect ratio, and size ratio, complementing PHASES.
- How is Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic) calculated? What is the core formula?
- Core: irregular morphology, AR (height/neck) ≥ 1.6, SR (height/parent-artery) ≥ 2. ≥ 2 core → higher risk; 1 → intermediate. Modifiers: hypertension, non-ICA location, smoking.
- When is Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic) used?
- Use for small aneurysms where PHASES discriminates poorly, weighting the three strong morphologic predictors plus clinical modifiers.
- What are the key clinical points for Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic)?
- Rupture risk should not be judged low by a diameter < 5 mm alone, since irregular morphology and high AR/SR strongly predict rupture (OR ~31/41/21). (original synthesis · not guideline verbatim) It is derived from Chinese-population studies as a complement to PHASES for small aneurysms. High-risk morphology favors active assessment/treatment or shorter follow-up with vessel-wall imaging.
- What are the limits and cautions when using Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic)?
- 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.
- How is Chinese Small-Aneurysm (≤ 5 mm) Rupture Risk (Morphologic) calculated in practice? Can you show a worked example?
- Inputs: Aneurysm height/depth 4.0 mm, Neck width (for AR) 2.5 mm, Parent-artery mean diameter (for SR) 2.0 mm, Morphology Regular, Hypertension Absent, Location ICA internal carotid artery, Smoking Absent → Result: Small-aneurysm rupture risk 2 core high-risk · higher rupture risk（Aspect ratio AR: 1.60 (height/neck; ≥ 1.6 high-risk) ⚠ high, Size ratio SR: 2.00 (height/parent-artery diameter; ≥ 2 high-risk) ⚠ high, Core high-risk features: aspect ratio AR ≥ 1.6, size ratio SR ≥ 2 (2 items)） Inputs: Aneurysm height/depth 4.0 mm, Neck width (for AR) 2.5 mm, Parent-artery mean diameter (for SR) 2.0 mm, Morphology Irregular (lobulated/daughter sac/bleb), Hypertension Present, Location ACA/Pcom/posterior circulation, Smoking Present → Result: Small-aneurysm rupture risk 3 core high-risk · higher rupture risk（Aspect ratio AR: 1.60 (height/neck; ≥ 1.6 high-risk) ⚠ high, Size ratio SR: 2.00 (height/parent-artery diameter; ≥ 2 high-risk) ⚠ high, Core high-risk features: irregular morphology (lobulated/daughter sac), aspect ratio AR ≥ 1.6, size ratio SR ≥ 2 (3 items)）