Distinction between benign and malignant adrenal masses: value of MR imaging (in phase, opposed phase)

In order to determine the difference between benign and malignant adrenal masses using T1 GRE chemical shift phase and out of phase, classifying the lesions with fat content, we examined 12 patients with lesions focalized in the adrenal gland, 6 male and 6 female, previously studied by CT with and without contrast. All of them had one or more lesions in the adrenal glands before the MRI study. The MRI was made using a superconductor 1.5 Tesla equipment with body coil. Axial samples, 7 mm thick, with a 1.4 mm gap were always obtained, following the protocol of our hospital, which includes T1 and T2. A qualitative analysis of the images was made, based on the experience of 3 observers.A quantitative analysis was carried out by calculating the difference in the signal intensity between the phase and the out of phase with the signal intensity in areas of interest: adrenal-liver, adrenal-spleen. The intensity of the signal was significantly different between adenomas and metastases in out of phase (98%), but not in phase. To conclude, the chemical shift techniques using sustained respiration in out of phase GRE in MRI are an excellent methods to discriminate adrenal adenomas from metastases. (author)