Adrenal CT Washout (adenoma vs non-adenoma)
Adrenal CT washout: absolute washout = (enhanced − delayed)/(enhanced − unenhanced) and relative washout = (enhanced − delayed)/enhanced, characterizing a lipid-poor adenoma.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Enhanced (portal-venous) HU
- 80
- Delayed (15 min) HU
- 35
- Unenhanced HU
- 15
Result: Absolute washout 69.2%, relative washout 56.3% — lipid-poor adenoma.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Absolute
- APW = (enhanced − delayed)/(enhanced − unenhanced) × 100; ≥ 60% is a lipid-poor adenoma.
- Relative
- RPW = (enhanced − delayed)/enhanced × 100; ≥ 40% is an adenoma (when no unenhanced scan). Unenhanced ≤ 10 HU is already a lipid-rich adenoma.
What you enter
- Enhanced (portal-venous) HU
- Delayed (15 min) HU
- Unenhanced HU
How this is calculated
Caoili EM, Korobkin M, Francis IR, et al. Adrenal masses: characterization with combined unenhanced and delayed enhanced CT. Radiology. 2002;222(3):629-633. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.