Differentiate adrenal adenomas from other masses using CT washout calculations.
CT Density (HU)
Mass Assessment
Absolute Washout71.4%
Relative Washout50.0%
Likely Adenoma
Adrenal Imaging Profile
Thresholds
≥ 60%Absolute (Diagnostic for Adenoma)
≥ 40%Relative (Diagnostic for Adenoma)
About this calculator
Overview
Adrenal washout calculations are used in radiology to differentiate lipid-poor adrenal adenomas from other adrenal masses like metastases or pheochromocytomas. Adenomas tend to 'wash out' (lose contrast) faster than other types of masses.
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Pro Tips
Delayed CT is typically taken 10 to 15 minutes after contrast injection.
Always check unenhanced phase first; if < 10 HU, further washout math may not be necessary.
Calculations are less reliable in patients with renal failure due to altered contrast kinetics.
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Fun Facts
"Unenhanced density < 10 HU is diagnostic of a lipid-rich adenoma."
"Absolute washout ≥ 60% is typically diagnostic of an adenoma."
"Relative washout ≥ 40% is typically diagnostic of an adenoma."
"HU stands for Hounsfield Units, the standard unit of CT density."
