[Image diagnosis of adrenal disorders--II. Cushing's syndrome]

Comparative study of image diagnosis of ultrasonography (US) by linear electronic scanner, computed tomography (CT), and adrenal scintigraphy was performed in 14 patients with Cushing's syndrome. Adrenal imaging by scintigraphy was performed at the 5th and 6th day or further 7th day following the injection of 1 mCi of Adosterol. Cushing's disease (11 cases) US failed to detect the adrenals in 4 cases examined. Measurement of the adrenals on CT film demonstrated the enlargement of adrenals (greater than mean + 2SD) in 6 of 7 cases (85.7%). Scintiscanning showed the increased uptake of bilateral adrenals in 4 of 10 cases (40%). Adrenal scintigraphy with dexamethasone pretreatment (DP) still demonstrated the isotope uptake of bilateral adrenals in all of those 4 cases tested, although the other 6 cases were not studied with DP. From these findings, it was suggested that the measurement of adrenal size by CT was useful for the additional image diagnosis of Cushing's disease, and the adrenal scintigraphy with DP was also available for complementary study of Cushing's disease. Cushing's syndrome due to adrenocortical adenoma (3 cases) In one case examined by US, which had the smallest adenoma (0.6 X 1.0 X 2.0 cm) in this syndrome, the adenoma was not detected. All of 3 adrenal adenomas (2.6 X 2.6 X 2.2 cm to 0.6 X 1.0 X 2.0 cm) were detected by CT. Adrenal scintigraphy demonstrated good uptake by adrenal adenoma but no visualization of the contralateral adrenal in every case.