IWS 67 - Falsely right and wrongly true: Navigating CEUS misinterpretations

This lecture explores the diagnostic traps in contrast-enhanced ultrasound (CEUS) that lead to false-positive and false-negative interpretations when characterizing focal liver lesions. Although late-phase washout is a hallmark of malignancy, numerous benign lesions, such as hemangiomas, focal nodular hyperplasia (FNH), hepatocellular adenoma (HCA), inflammatory lesions, and granulomatous processes—may also show hypoenhancement or washout, creating a “falsely malignant” impression. Conversely, very rarely some malignant lesions, including certain hepatocellular carcinomas and rare hypervascular metastases, especially neuroendocrine tumors, may lack washout entirely, appearing “wrongly benign.
The lecture highlights:
• Mechanisms behind atypical enhancement patterns (vascular physiology, fibrosis, steatosis, microbubble destruction, lesion subtype).
• How to recognize pseudo-washout and avoid technical artifacts.
• How to identify malignant lesions that deceptively retain enhancement into the late phase.
• Practical strategies to improve confidence in CEUS interpretation, including timing, intermittent scanning, and correlation with lesion architecture.
• The session emphasizes a pattern-based, physiology-guided approach to CEUS, helping examiners avoid misclassification and make safer, more accurate decisions in clinical practice.