Scanning of the adrenals in Cushing's syndrome

131I-19-iodocholesterol adrenal scans were obtained in seven patients with Cushing's syndrome. Characteristic imaging patterns were seen in three patients with bilateral adrenal hyperplasia with symmetrical uptake of the isotope. Two patients with adrenocortical adenoma and one patient with a well-differentiated adrenocortical carcinoma showed intense activity in one adrenal gland and absent activity in the contralateral gland. In one patient with adrenal nodular hyperplasia asymmetrical uptake was found with increased activity in the right adrenal gland where a larger adenomatous nodule was found at histologic examination. Adrenal imaging with radioactive cholesterol is a useful noninvasive technique for the diagnosis and treatment of Cushing's syndrome.