title: Neonatal Cranial Ultrasound: Are Current Safety Guidelines Appropriate?
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.
authors.affiliation: Department of Medical Imaging and Radiation Sciences, Monash University, Malvern, Victoria, Australia; Department of Medical Imaging, St. Francis Xavier Cabrini Hospital, Malvern, Victoria, Australia; Department of Medical Imaging, Mercy Hospital for Women, Heidelberg, Victoria, Australia.
authors.forename: Assema
authors.initials: A
authors.lastname: Lalzad
authors.affiliation: Monash Newborn, Monash Medical Centre, Clayton, Victoria, Australia; The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Victoria, Australia; Department of Pediatrics, Monash University, Clayton, Victoria, Australia.
authors.forename: Flora
authors.initials: F
authors.lastname: Wong
authors.affiliation: Department of Medical Imaging and Radiation Sciences, Monash University, Malvern, Victoria, Australia. Electronic address: Michal.schneider@monash.edu.
authors.forename: Michal
authors.initials: M
authors.lastname: Schneider
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D012886:Skull / Q000000981:diagnostic imaging; D014463:Ultrasonography / Q000009:adverse effects / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000009:adverse effects / Q000379:methods
keywords: Cranial ultrasound; Fetal brain heating; Mechanical index; Preterm infants; Thermal index; Ultrasound safety