WFUMB Liver Ultrasound Fusion Imaging Technical Review and Position Statement: Focus on CT/MRI-Based Fusion

Area of Science:

• Medical Imaging
• Interventional Radiology
• Diagnostic Ultrasound

Background:

• Ultrasound fusion imaging combines real-time ultrasonography (US) with pre-acquired CT/MRI for enhanced spatial correlation.
• It is crucial for liver imaging and interventions when conventional B-mode US has limitations in lesion visualization.

Purpose of the Study:

• To evaluate the technical accuracy (target registration errors) of ultrasound fusion imaging.
• To assess the improvement in lesion visibility using fusion imaging compared to conventional methods.
• To provide an expert consensus on its clinical utility in liver interventions.

Main Methods:

• Systematic review of literature from January 2012 to January 2025.
• PICO framework used to address target registration errors and lesion visibility.
• Searched PubMed, Scopus, Embase, and IEEE Xplore, including manual citation tracking and AI-assisted queries.

Main Results:

• Consistently high technical accuracy with target registration errors of ~1-3 mm (phantom) and ~4-14 mm (clinical).
• Fusion imaging significantly improved detection of occult liver lesions, increasing diagnostic yield and enabling successful interventions in up to 95% of cases.
• Favorable safety profile with major complication rates below 2%, particularly beneficial for tumors in challenging locations.

Conclusions:

• Ultrasound fusion imaging enhances spatial accuracy and guidance for liver interventions, maintaining a low complication rate.
• Advancements in AI and AR are expected to further optimize fusion imaging workflows and outcomes.
• Supports the broader adoption of fusion imaging as a vital tool in liver imaging and intervention.