Updated WFUMB Safety Guidance Defines Exposure Time Limits for High-Risk Ultrasound Scanning

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Data Quality: STRONG
Summary of  Ultrasound in Medicine & Biology https://doi.org/10.1016/j.ultrasmedbio.2026.05.022
Dr. J. Brian Fowlkes et al.

Points

The World Federation for Ultrasound in Medicine and Biology published harmonized international safety guidelines regulating maximum exposure times associated with displayed Thermal Index values during ultrasound examinations.
Global safety experts and representatives from regulatory agencies like the FDA collaborated to unify existing recommendations from leading medical ultrasound societies into one standard framework.
Updated guidelines define exposure time as total continuous beam exposure to a specific anatomical structure and categorize procedures based on potential tissue heating risk levels.
High risk categories retain stringent maximum exposure limits for obstetric, gynecological, and neonatal scanning, while newly incorporating pediatric and premature infant head and spine examinations.
The harmonized standards provide essential guidance for clinicians and manufacturers to prevent ultrasound induced thermal bioeffects as artificial intelligence and novel diagnostic techniques continue expanding.

Summary

This study evaluated new international consensus guidelines established by the World Federation for Ultrasound in Medicine and Biology (WFUMB) Task Force to harmonize recommended maximum exposure times associated with displayed Thermal Index (TI) values. Published in Ultrasound in Medicine & Biology, the effort addresses safety concerns stemming from novel clinical applications, artificial intelligence integration, and exposure in thermally sensitive tissues like bone, nerve, and gas bodies. Given that diagnostic ultrasound supports approximately 1,000,000,000 examinations annually worldwide, standardizing maximum exposure durations across BMUS, AIUM, and EFSUMB frameworks is critical to maintaining long-term safety records.

The consensus framework formally defines exposure time as the total duration a specified anatomical structure is continuously exposed to the ultrasound beam during an examination. To mitigate potential bioeffects and tissue heating, the updated guidance categorizes procedures into two distinct risk profiles based on potential harm from temperature elevation. Category 1 encompasses higher thermal risk applications, maintaining existing maximum recommended exposure times for obstetric imaging, gynecological scanning where pregnancy is possible, and neonatal head and spine examinations, while explicitly adding premature infant and pediatric head and spine scanning to this protected classification.

The guidelines provide a unified reference standard for manufacturers, sonographers, clinicians, and regulatory bodies including the Food and Drug Administration. The task force concludes that establishing standardized exposure time limits based on displayed Thermal Index parameters provides clear operational boundaries during diagnostic scanning. This global harmonization mitigates ultrasound-induced thermal bioeffects, protects vulnerable pediatric and fetal patient populations, and ensures clinical safety across emerging therapeutic and diagnostic modalities worldwide

Link to the article: https://www.umbjournal.org/article/S0301-5629(26)00208-5/fulltext

References

Fowlkes, J. B., Akiyama, I., Bader, K., Ter Haar, G., Harris, G., Miloro, P., Moran, C. M., Nomura, J., Verma, P., Wear, K., & Whalley, G. (2026). Recommended maximum exposure times for displayed thermal index (Ti) values. Ultrasound in Medicine & Biology, 52(11), 2305–2307. https://doi.org/10.1016/j.ultrasmedbio.2026.05.022