Neonatal Cranial Ultrasound: Are Current Safety Guidelines Appropriate?

Overview	The authors reviewed the literature to explore the evidence on ultrasound heating on fetal and neonatal neural tissue. Ultrasound exposure of the fetal or neonatal brain may lead to a significant temperature elevation (4.3 and 5.6°C) that may potentially affect neuronal structure and function and affect behavioral and cognitive function. Because most safety studies were carried out more than 25 years ago using non-diagnostic equipment with power outputs much lower than those of modern machines, new studies are imperative to provide current clinical guidelines and safety recommendations.
Authors	Assema Lalzad, Flora Wong, Michal Schneider
Journal	Ultrasound in Medicine and Biology, March 2017, Volume 43, Issue 3, Pages 553-560
Recommendation/Comment	Relevant for GYN/OBS sonography.
Clinical implication	Operators must be aware that ultrasound exposure of the fetal or neonatal brain may lead to a significant temperature elevation and should limit the use of Doppler mode, as well as reduce the overall duration of the neonatal cranial scan.
Link (DOI)	https://doi.org/10.1016/j.ultrasmedbio.2016.11.002
Ultrasound speciality	Quality and Safety issues, Physics and US equipment, pediatric and neonatal sonography

Original abstract:

Neonatal Cranial Ultrasound: Are Current Safety Guidelines Appropriate?

Assema Lalzad, Flora Wong, Michal Schneider

Ultrasound in Medicine and Biology, March 2017, Volume 43, Issue 3, Pages 553-560

DOI: https://doi.org/10.1016/j.ultrasmedbio.2016.11.002

Abstract:

Ultrasound can lead to thermal and mechanical effects in interrogated tissues. We reviewed the literature to explore the evidence on ultrasound heating on fetal and neonatal neural tissue. The results of animal studies have suggested that ultrasound exposure of the fetal or neonatal brain may lead to a significant temperature elevation at the bone-brain interface above current recommended safety thresholds. Temperature increases between 4.3 and 5.6°C have been recorded. Such temperature elevations can potentially affect neuronal structure and function and may also affect behavioral and cognitive function, such as memory and learning. However, the majority of these studies were carried out more than 25 y ago using non-diagnostic equipment with power outputs much lower than those of modern machines. New studies to address the safety issues of cranial ultrasound are imperative to provide current clinical guidelines and safety recommendations.

Keywords:

Cranial ultrasound; Fetal brain heating; Mechanical index; Preterm infants; Thermal index; Ultrasound safety.