Usefulness of contrast-enhanced ultrasound for the diagnosis of recurrent renal cell carcinoma in contralateral kidney

We studied contrast‐enhanced ultrasound (CEU) for recurrence of renal cell carcinoma (RCC) at the contralateral kidney during postoperative follow up of localized renal cell carcinoma. CEU successfully detected all recurring cases, despite the fact that 5/6 cases were observed using conventional ultrasound; the remaining one case was not detected using conventional ultrasound. CEU using Levovisto successfully revealed renal tumors as RCC. Lesions were diagnosed as cystic renal tumors by Bosniac classification, and pathological findings demonstrated RCC, in accordance with the prior tumor.