Differentiation between Benign and Malignant Adrenal Mass using Contrast-Enhanced Ultrasound

Purpose: Adrenal masses can be detected by ultrasound with high sensitivity and specificity. The aim of the present study was to evaluate CEUS in a large patient population using CEUS patterns identified in a previous pilot study. Materials and Methods: 116 adrenal masses were evaluated by ultrasound, including CEUS with the contrast agent Sonovue (R). The dynamic of contrast enhancement (CE) was analyzed using time-intensity curves. The time of the first CE in the adrenal mass was used to define four CEUS patterns: pattern I=early arterial CE, pattern II=arterial CE, pattern III=late CE, pattern IV=no CE. In addition, all patients received CT/MRI and hormonal testing. In suspicious cases biopsy or adrenalectomy was performed. Results: CEUS patterns I&II were seen in all patients with primary or secondary malignant lesions of the adrenal gland (n=16). The sensitivity and specificity of CEUS for the diagnosis of malignant adrenal mass were 100% (Cl [75;100]) and 67% (Cl [56;75]), respectively. Overall histology was available as a reference method for 40 adrenal masses. In 68% of histologically diagnosed adrenal masses. MRI/CT and CEUS were congruent concerning the characterization of malignant versus benign adrenal mass. Conclusion: Contrast-enhanced ultrasound may be a useful method in the diagnostic work-up of adrenal mass with excellent sensitivity for the diagnosis of malignancy.