Comparison of contrast-enhanced sonography with MRI in the diagnosis of complex cystic renal masses.

Abstract

To compare the diagnostic performance of contrast-enhanced ultrasound (CEUS) with MRI for complex cystic renal masses. The study received approval from our Ethics Committee, and all subjects provided informed consent. Seventy-one complex cystic renal masses were assessed using CEUS and MRI in 59 patients (44 men and 15 women; age range, 21-78 years; mean age, 49.6 years). The masses were classified as malignant or benign based on the Bosniak classification system (benign, categories II and IIF; malignant, categories III and IV). The diagnostic performances of CEUS and MRI for complex cystic renal masses were compared with the final diagnosis in each case obtained by histopathology (n = 43) or imaging follow-up (n = 28). Among 71 complex cystic renal masses, 35 were benign and 36 were malignant. The sensitivity, specificity, and overall accuracy of CEUS in assessing the masses were 97.2%, 71.4%, and 84.5% versus 80.6%, 77.1%, and 78.9% for MRI; the areas below the receiver operating characteristic curves of CEUS and MRI were 0.84 and 0.79, respectively. The agreement between the classification using CEUS and the final diagnoses was fair to good (κ = 0.70), and the agreement between MRI and the final diagnoses was also fair to good (κ = 0.58). CEUS has higher diagnostic sensitivity and accuracy but lower specificity than MRI for classifying complex cystic renal masses. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:203-209, 2015.