SPECTRUM OF CT FINDINGS IN NONMALIGNANT DISEASE OF THE ADRENAL-GLAND

Computed tomography (CT) plays a leading role in tile evaluation of no nmalignant disease of the adrenal gland, CT is highly accurate in the localization of adrenal masses in patients with diseases associated wi th hyperfunctioning adrenal glands such as Gushing syndrome and Gushin g disease, Corm syndrome, adrenal tumors leading to virilization or fe minization, and pheochromocytomas. CT permits a specific diagnosis of acute or subacute adrenal hematoma and myelolipoma, Hematomas are roun d to oval and have increased attenuation (50-90 HU) that decreases on follow-up CT scans. Myelolipomas typically manifest as a well-defined suprarenal mass with an attenuation of -30 to -115 HU. Adrenal cysts a re usually round to oval and manifest as a hypoattenuating mass with a smooth, thin wall. CT is useful in the evaluation of patients with Ad dison disease, particularly the subacute form secondary to tuberculosi s or disseminated histoplasmosis. Findings typically include bilateral adrenal enlargement with a central necrotic area of hypoattenuation a nd peripheral enhancement, Thin-section unenhanced CT permits accurate measurement of attenuation and can be used to differentiate adrenal a denoma from metastasis in a cancer patient with an indeterminate mass: Attenuation of 10 HU or less usually indicates adenoma rather than ca ncer, If the mass is found incidentally at contrast material-enhanced CT, delayed scans obtained as early as 5-15 minutes after intravenous administration of contrast material appear to have comparable accuracy .