Contrast-enhanced ultrasound as a problem-solving tool and irreversible electroporation for a...

Interventional ultrasound (IUS) supported by contrast-enhanced ultrasound (CEUS) enables accurate real-time characterization and image-guided treatment of focal liver lesions. In nonsurgical candidates with colorectal liver metastases (CRLM), irreversible electroporation (IRE) is an emerging nonthermal ablative option, particularly for lesions adjacent to major vascular or biliary structures. We report the case of a 52-year-old woman with locally advanced rectal adenocarcinoma and multiple hepatic cysts resulting in a complex multicystic liver architecture, who presented with a 20-mm indeterminate lesion in segment IVs, highly suspicious for metastatic disease. After systemic chemotherapy, radiotherapy, and surgical resection of the primary tumor, the lesion persisted and measured 17 mm on follow-up imaging, with inconclusive findings on conventional imaging. CEUS played a pivotal role in distinguishing treatment-related perfusion abnormalities from viable tumor, ultimately demonstrating rim arterial enhancement and rapid portal washout highly suggestive of persistent viable metastasis. Because of the lesion's central location and proximity to the hepatic vein and adjacent biliary structures, surgical resection and thermal ablation were considered less suitable. Therefore, IRE was selected as the most appropriate percutaneous local treatment. The procedure was successfully performed under ultrasound guidance, with immediate CEUS confirmation of complete ablation. At the most recent imaging follow-up (October 2025, 6 months after treatment), no evidence of residual or recurrent liver disease was observed.