Usefulness of contrast enhanced ultrasound for evaluation of cystic renal masses.

Contrast enhanced ultrasound(CE) consists of the intravenous injection of gasmicrobubbles and their detection within the kidney in differentphases. CE is more accurate than contrast enhancedtomography for detection of septa and wall thicknessvascularization in cystic renal lesions. The purposes ofthis study are to confirm the usefulness of this tool in thecharacterization of complex cystic renal masses and toassess its histological correlation. MATERIALS AND METHODS: Retrospective observationalstudy of 78 patients with complex or indeterminatecystic renal masses who underwent a CE betweenJanuary 2015 - January 2020. RESULTS: Lesions with high suspicion of malignancy(Bosniak III and IV) were identified in 35 patients(45%). A surgical approach was taken in 23 (30%): 18patients with histology of renal cell carcinoma, and onlyin 4 the histology was benign. CE involved a change intherapeutic management due to better definition of thelesion in 48 patients (61.5%). CE has a sensitivity 100%,specificity 91.5%, PPV 81.8%, NPV 100%, and CE hadan important confidence level showed by the area underthe ROC curve (AUC = 0.968). CE is a useful tool in the characterizationof complex cystic renal lesions. It allows abetter definition of the Bosniak classification for thoseindeterminate or doubtful cases on CT that couldgenerate a change in the therapeutic attitude in manycases. It has a good image - histology relation.