Colour Doppler and contrast-enhanced ultrasound diagnosis of a delayed intrahepatic pseudoaneurysm after liver biopsy: a case report and literature review.

Percutaneous liver biopsy is widely performed and generally safe; however, rare vascular complications may occur. We report a 43-year-old man with a history of allogeneic haematopoietic stem cell transplantation undergoing ultrasound evaluation for multiple hepatic and splenic lesions detected during investigation of persistent fever. After a non-diagnostic biopsy, follow-up ultrasound three weeks later demonstrated vascular features within a left-lobe lesion selected for repeat sampling. Contrast-enhanced ultrasound (CEUS) showed rapid and persistent arterial enhancement. Colour Doppler revealed turbulent bidirectional flow with a "yin-yang" pattern, and pulsed-wave Doppler demonstrated a characteristic "to-and-fro" waveform consistent with pseudoaneurysm. CT angiography confirmed a pseudoaneurysm arising from a peripheral intrahepatic branch of the left hepatic artery. The patient remained asymptomatic, haemodynamically stable and without laboratory evidence of bleeding. Selective endovascular embolisation was performed. This case highlights how combined CEUS and Doppler may detect delayed, clinically silent vascular complications after liver biopsy.