Diffusion-Weighted MR Imaging in the Differential Diagnosis of Adrenal Adenomas and Nonadenomatous Adrenal Masses

Objective: The aim of our study was to demonstrate the feasibility of body diffusion-weighted magnetic resonance (DW MR) imaging in the differential diagnosis of adrenal adenomas and non-adenomatous adrenal masses. Material and Methods: Thirty-seven adrenal masses in 32 consecutive patients (18 women, 14 men) were included in this prospective study. Of all the masses, 21 were adenomas and 16 were non-adenomatous adrenal masses. DW MR images were obtained by a body coil using a multisection single-shot echo planar sequence on the axial plane without breath holding (water excitation with b value of 50, 400 and 800 s/mm(2)). Signal intensities of the adenomas and non-adenomatous masses were measured for each b factor of 400 and 800 s/mm(2) using a region of interest (ROI). In addition, the signal intensities for apparent diffusion coefficient (ADC) calculation were measured. Mann Whitney U Test was used to compare signal intensities for each b factor (400 and 800 s/mm(2)) and for ADC values between the adenomas and non-adenomatous masses. Results: No significant difference was noted (p > 0.05) for ADC values between the two groups. Similarly, signal intensities with b factors of 400 and 800 s/mm(2) did not demonstrate a significant difference (p > 0.05) between the groups. Conclusion: DW MR imaging is not an effective method in the differential diagnosis of adenomatous and non-adenomatous lesions in adrenal glands