[CT and MRI in the differential diagnosis of lesions of the adrenal gland]

Abstract

Adrenal gland tumors are often incidental findings during imaging of the upper abdomen. In the majority of cases, benign adrenal gland tumors, especially nonfunctioning adenomas, are diagnosed, although the evaluation of dignity is essential in order to avoid unnecessary biopsy and tumor extirpation. Lipid-containing adrenocortical adenomas and nonadenomas can be differentiated with high diagnostic accuracy and specificity by computed tomography (CT) and magnetic resonance imaging (MRI). The fat content of these lesions can be correlated with CT attenuation values or with signal decrease in chemical shift imaging in MRI. Furthermore, low-fat adenomas can be distinguished from nonadenomas with delayed contrast enhancement and washout characterization. For the differentiation of non-fat-containing nonadenomas (metastases, lymphoma, pheochromocytoma, and inflammatory processes), morphological imaging criteria in CT and MRI (signal alterations, contrast media enhancement), clinical signs and laboratory test are essential in order to establish the diagnosis. The localization of functioning adenomas can be easily performed with CT and MRI. Both imaging techniques reveal typical findings of lesions-like cysts and myelolipomas.