CT guided percutaneous adrenal biopsy for lesions with equivocal findings in chemical shift MR imaging

The aim of this study was to evaluate the usefulness of CT guided adrenal biopsy in patients with equivocal MR chemical shift imaging findings. Fifty seven patients, 32 with history of malignancy and 25 without history of malignancy, 30 men and 27 women (33-82 years, mean age:58.8 years), with equivocal findings in chemical shift MR imaging, were subjected to CT guided percutaneous adrenal biopsy. From the 57 lesions that were sent for histopathological evaluation, 31 proved to be metastases (54.4%), 20 adenomas (35.1%), 3 cortical carcinomas (5.3%), 1 benign pheochromocytoma (1.8%) and 2 samples were non diagnostic(3.5%). In oncology patients metastases were found in 28/32 of the patients (87.5%) and adenomas in 3/32 (9.4%), while in patients without history of malignancy, metastases were found in 3/25 of the patients (12%) and adenomas in 17/25 (68%). CT guided percutaneous adrenal biopsy is a safe and accurate method for a definite diagnosis of adrenal lesions. Since most adrenal lesions are benign, dedicated adrenal imaging is necessary for choosing which of them have to be further evaluated by biopsy. Chemical shift adrenal imaging alone seems to be a reliable method and can be used alternatively to CT enhancement washout technique for selecting which lesions are suspicious of malignancy and have to be investigated with biopsy, especially in cases where iodine contrast media is contraindicated.