Diagnostic value of combined versus individual MRI parameters in distinguishing adenomatous from non-adenomatous adrenal lesions in cancer patients

PurposeOur aim was to evaluate the diagnostic value of MRI using different parameters in differentiation of adenomas versus non-adenomas adrenal lesions.Materials and methodsForty-five patients with 48 adrenal masses (28 lipid rich adenomas, 3 lipid poor adenomas, 15 metastases and 2 lymphoma) were retrospectively evaluated with MRI. The mean diameter of adrenal mass, T2WI signal, signal drop on chemical shift imaging (CSI) and enhancement pattern were assessed separately and in various combinations. Accuracies, sensitivities, specificities, PPV, NPV and P values by Chi-square test were calculated for individual and combined parameters.ResultsSignal drop on CSI and enhancement pattern were the most statistically significant diagnostic discriminators of adenomatous and non-adenomatous lesions with accuracies, specificities and sensitivities of 93.8%, 90.3%, 100% and 91.7%, 93.5%, 88.2%, respectively (P-value <0.0001). The best performance of a combination of parameters was obtained after exclusion of the size, with an accuracy of 89.6% (P-value <0.0001).ConclusionThe most specific predictors for adrenal mass characterization were CSI signal drop and Gd-DTPA enhancement characteristics. Combining the MR parameters did not prove superior to those two individual parameters, however it yielded a valuable diagnostic protocol for distinguishing the adrenal masses, considering that size criterion should not be used as an individual discriminator.