Adrenal venous sampling interpretation and molecular imaging as localization tool in primary aldosteronism.

Primary aldosteronism (PA) is the leading cause of secondary hypertension. In general, two principal subtypes are distinguished: A lateralized form in which aldosterone hypersecretion originates from a single adrenal gland, and a non-lateralized form characterized by bilateral adrenal involvement. In patients with lateralized PA, adrenalectomy yields more favorable clinical and biochemical outcomes than pharmacological therapy. Accurate subtype classification is therefore essential to guide the optimal treatment. Adrenal venous sampling (AVS) remains the gold standard for localizing aldosterone excess, though its technical difficulty and limited availability pose challenges. In addition, molecular imaging has emerged as a promising non-invasive alternative in recent years, with novel PET tracers showing potential to complement or replace AVS in selected patients. This chapter summarizes the indications, technical aspects, and interpretation of AVS, and reviews current molecular imaging approaches, emphasizing their potential role as complementary tools in the diagnostic work-up of PA.