Dual-Energy CT for Characterization of the Incidental Adrenal Mass: Preliminary Observations

The purpose of our study was to evaluate the accuracy of virtual unenhanced images reconstructed from contrast-enhanced dual-energy CT for the differentiation of incidental adrenal masses in comparison with standard unenhanced CT. One hundred-forty patients (mean age, 74±9 years) underwent unenhanced and contrast-enhanced CT of the abdomen, the latter acquired with dual-energy for reconstruction of virtual unenhanced images. Two blinded and independent readers (R1 and R2) measured attenuation of each incidental adrenal mass on standard unenhanced and virtual unenhanced images using an optimized dual-energy three-material decomposition algorithm. Fifty-one incidental adrenal masses were found in 42 of 135 patients (31%); 39 incidental adrenal masses were ≥1 cm. On the basis of unenhanced CT, 29 of 51 incidental adrenal masses and 22 of 39 incidental adrenal masses≥1 cm were classified as benign (HU