Imaging recommendation · Abdomen · Pelvis

Primary aldosteronism (Conn syndrome) — adrenal imaging

Q: What's the alternative imaging for primary aldosteronism (conn syndrome) — adrenal imaging when lateralization for surgical planning?

Adrenal vein sampling (IR procedure) (iv contrast).

Q: What's the alternative imaging for primary aldosteronism (conn syndrome) — adrenal imaging when ct equivocal or contrast contraindicated?

MRI — Adrenal MRI with chemical-shift (iv contrast).

Q: What's the alternative imaging for primary aldosteronism (conn syndrome) — adrenal imaging when suspected adrenocortical carcinoma (lesion > 4 cm, heterogeneous)?

CT — Adrenal CT + FDG-PET (iv contrast).

Recommended: Adrenal CT (thin-section, multiphase) is the preferred imaging study for primary aldosteronism (conn syndrome) — adrenal imaging. Imaging follows biochemical confirmation (elevated aldosterone/renin ratio + confirmatory testing).

Recommended study

Adrenal CT (thin-section, multiphase)

CT IV contrast Preferred Abdomen · Pelvis Outpatient Reviewed 2026-05

Imaging follows biochemical confirmation (elevated aldosterone/renin ratio + confirmatory testing). CT with thin sections (≤ 3 mm) through the adrenals — looks for unilateral adenoma, bilateral hyperplasia, or carcinoma. Adrenal vein sampling (AVS) is the gold standard for lateralization before adrenalectomy — imaging alone is insufficient in patients > 35 years or with bilateral abnormalities.

If the default doesn't apply

Lateralization for surgical planning

Adrenal vein sampling (IR procedure) IV contrast

CT equivocal or contrast contraindicated

MRI Adrenal MRI with chemical-shift IV contrast

Suspected adrenocortical carcinoma (lesion > 4 cm, heterogeneous)

CT Adrenal CT + FDG-PET IV contrast

Watch-outs

Imaging-only lateralization in older patients

Non-functional adenomas are common with age — AVS is mandatory before adrenalectomy to confirm the imaged lesion is the culprit.

Bilateral adrenal nodularity on CT

Doesn't rule out unilateral surgical disease — AVS may still identify a dominant secretor.

Pearls

Aldosterone-producing adenomas are usually small (< 2 cm), lipid-rich — low Hounsfield (< 10 HU) on non-contrast CT.
AVS success: aldosterone:cortisol ratio comparison left/right + IVC; selectivity index > 2:1 confirms catheter position.
Carcinoma: > 4 cm, heterogeneous, high attenuation, calcifications, local invasion.