Adrenal Nodule Washout (APW / RPW) — free guideline decision tool
Turn adrenal washout into a tool: enter unenhanced/enhanced/delayed HU to compute APW and RPW, flag adenoma at APW ≥60% or RPW ≥40%, and reconcile with the unenhanced-HU context. 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.
| Unenhanced HU (leave blank if none; RPW only) | 25 |
|---|---|
| Enhanced HU (portal venous, 60–70 s) | 90 |
| Delayed HU (15 min) | 45 |
→AssessmentConsistent with adenoma
- Absolute washout APW：69.2% (threshold ≥60%) = (E−D)/(E−U)
- Relative washout RPW：50.0% (threshold ≥40%) = (E−D)/E
- Washout read：Meets threshold (APW ≥60% or RPW ≥40%)
Common questions
What is Adrenal Nodule Washout (APW / RPW)?
Turn adrenal washout into a tool: enter unenhanced/enhanced/delayed HU to compute APW and RPW, flag adenoma at APW ≥60% or RPW ≥40%, and reconcile with the unenhanced-HU context. Instant, browser-side.
How is Adrenal Nodule Washout (APW / RPW) calculated? What is the core formula?
APW = (E−D)/(E−U)×100 (needs unenhanced); RPW = (E−D)/E×100 (used when no unenhanced). Thresholds: APW ≥60% or RPW ≥40% suggests adenoma.
When is Adrenal Nodule Washout (APW / RPW) used?
Characterizing adrenal incidentalomas (unenhanced > 10 HU, or no unenhanced series): adenoma (incl. lipid-poor) vs lesions needing further workup. HU measurement is done by the radiologist.
What are the key clinical points for Adrenal Nodule Washout (APW / RPW)?
APW = (E−D)/(E−U)×100, threshold ≥60%. RPW = (E−D)/E×100, threshold ≥40% (use when no unenhanced series). Unenhanced ≤10 HU → lipid-rich adenoma, washout unnecessary. Unenhanced > 43 HU → concerning for malignancy; do not call adenoma on washout alone. Pheochromocytoma / hypervascular metastases can be false-positive; less reliable for ≥4 cm or heterogeneous nodules.
What are the limits and cautions when using Adrenal Nodule Washout (APW / RPW)?
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 Adrenal Nodule Washout (APW / RPW) calculated in practice? Can you show a worked example?
Inputs: Unenhanced HU (leave blank if none; RPW only) 25, Enhanced HU (portal venous, 60–70 s) 90, Delayed HU (15 min) 45 → Result: Assessment Consistent with adenoma（Absolute washout APW: 69.2% (threshold ≥60%) = (E−D)/(E−U), Relative washout RPW: 50.0% (threshold ≥40%) = (E−D)/E, Washout read: Meets threshold (APW ≥60% or RPW ≥40%)）
Run Adrenal Nodule Washout (APW / RPW) now
Turn adrenal washout into a tool: enter unenhanced/enhanced/delayed HU to compute APW and RPW, flag adenoma at APW ≥60% or RPW ≥40%, and reconcile with the unenhanced-HU context. Instant, browser-side.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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