Ultrasound Case: The Pepsi Sign and a Surprising Vascular Finding

A benign-looking liver lesion turned out to be a hepatic artery pseudoaneurysm—all thanks to color Doppler.

The Big Picture

What looks like a simple hypoechoic cyst on ultrasound may hide a critical vascular pathology. Color Doppler is essential for distinguishing cystic lesions from vascular anomalies like pseudoaneurysms.

Key Takeaways

  • Always Doppler: Even cyst-like structures require Doppler evaluation to rule out vascular causes.
  • The Pepsi Sign: Swirling vascular flow within a lesion may signal a pseudoaneurysm.
  • High stakes: Hepatic artery pseudoaneurysms can mimic benign lesions but require urgent recognition and intervention.
  • Next steps: Interventional radiology embolization can be lifesaving.

Challenges Ahead

  • Differentiating pseudoaneurysms from other vascular or cystic lesions remains tricky.
  • Missing Doppler evaluation risks misdiagnosis and delayed treatment.
  • Awareness of teaching signs like the “Pepsi sign” is uneven among trainees.

Bottom Line

Never skip Doppler. The “Pepsi sign” may be the clue that transforms a benign-looking lesion into a critical vascular diagnosis.