For educational and reference use only. These calculators do not replace clinical judgement, local protocols, or a qualified clinician. Verify every result independently before it informs patient care.
Body imaging
Adrenal Nodule Washout (CT)
Computes absolute (APW) and relative (RPW) percentage washout from unenhanced, portal-venous (~60–75 s), and delayed (~15 min) attenuation. An unenhanced value ≤10 HU is diagnostic of a lipid-rich adenoma by itself; above that, APW ≥ 60% or RPW ≥ 40% supports a lipid-poor adenoma. Leave the unenhanced value blank if you only have enhanced + delayed (relative washout only).
Leave blank if not available; RPW still computes.
Result
-
Enter all values to calculate.
Formula
Unenhanced ≤10 HU → lipid-rich adenoma (no washout needed). Otherwise: APW = (Enhanced − Delayed) ÷ (Enhanced − Unenhanced) × 100 (adenoma if ≥60%); RPW = (Enhanced − Delayed) ÷ Enhanced × 100 (adenoma if ≥40%).
References
Disclaimer
Washout criteria assume a homogeneous nodule and standardised delayed timing (~15 min). They do not apply to markedly heterogeneous, haemorrhagic, or macroscopic-fat–containing lesions, or to known extra-adrenal malignancy without further work-up.
For educational and reference use only. These calculators do not replace clinical judgement, local protocols, or a qualified clinician. Verify every result independently before it informs patient care.
Training in Radiology?
Viewbox is free for radiology residents in India: daily spotter cases, timed OSCE-style exams, every calculator here, focus rooms, and a board of fellowships and jobs.