The value of contrast enhanced ultrasound (CEUS) in the characterisation of patients with renal masses.

Renal masses are frequently incidentally found on ultrasound. Contrast enhanced computed tomography (CECT) is regarded as the method of choice. Contrast enhanced ultrasound (CEUS) has a high impact for characterisation of hepatic lesions. Its use in renal masses has been less comprehensively studied. Two hundred and one patients referred for surgical treatment of a renal mass, 143 patients fulfilling inclusion criteria (histology and reference method). Baseline ultrasound and CEUS with BR1, histology obtained by surgery (89%) or biopsy (11%). Eighty-eight percent of the patients had renal lesions which were malignant and 12% benign lesions. Eighty percent had renal cell carcinoma (RCC). Seven percent of the lesions were cystic. Two patients were upgraded by CEUS from CECT Bosniak II into CEUS Bosniak III resp. IV. CEUS could predict malignancy with a sensitivity, specificity, positive, negative predictive value and accuracy in 97%, 45%, 91%, 75%, and 90%. The correct staging was diagnosed by CEUS (CECT) in 83% (69%). CEUS was superior to CECT in the staging and characterisation of RCC, also in the subgroup of patients with cystic lesions. CEUS can replace CECT e.g. in patients with allergies or contraindications against CECT. Multicentre studies are necessary to confirm the findings.