Validity of computerized tomography in adrenal diseases.

For diagnosis of adenomas in primary aldosteronism CT proved to be helpful. Although microadenomas have to be ruled out by selective venous sampling from both adrenal glands adenomas down to 8 mm in diameter can be visualized. Scintigraphy does not always permit reliable differentiation of unilateral adenoma from bilateral hyperplasia. -- in endogenous Cushing's syndrome adrenal carcinomas are underlying etiologically in about 10% of the cases. Since carcinomas are detected easily by CT it should be performed in the first place. Whereas adenomas and hyperplasia are easily diagnosed by scintigraphy carcinomas may escape scintigraphy. -- Pheochromocytomas, if situated in the vicinity of the kidneys, can be localized safely by CT. Contrary to adenomas, carcinoma and pheochromocytomas may be detected by CT without difficulty because of their size.