Contrast enhanced ultrasound characterization of surgically resected renal masses in patients on dialysis.

Diagnostic work-up of suspicious renal masses has traditionally been conducted with contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI). However, patients who are not candidates for intravenous contrast due to allergy, renal insufficiency, or those on dialysis are discouraged from utilizing traditional contrast imaging due to risks of anaphylaxis, nephrotoxicity, or further kidney damage. We evaluated contrast-enhanced ultrasound (CEUS) in patients on dialysis who would benefit from alternative imaging options to CECT or MRI. Following IRB approval, nine renal masses from eight patients (aged 54-74 years) with chronic renal insufficiency were evaluated with CEUS and shown to be enhancing after the intravenous administration of ultrasound contrast agent. The ultrasound contrast agent Lumason (Sulfur hexafluoride lipid type-A microspheres, Bracco Diagnostics, Monroe Township, NJ, USA) was utilized. Enhancement was considered present when microbubble contrast agent was visualized within the lesion of interest. Nine CEUS enhancing masses were pathologically examined following laparoscopic radical nephrectomy. Eight of the nine lesions were renal cell carcinoma (two clear cell, four papillary, two cystic). One resected mass was an unspecified benign renal lesion. In this sample of surgically resected tumors, CEUS was effective in characterizing renal lesions as solid neoplasms or complex cystic lesions suspicious for neoplasm-findings which merit further investigation.