title: Brain Surface Heating After Exposure to Ultrasound: An Analysis Using Thermography.
abstract: Ultrasound is the imaging modality of choice to monitor brain pathologies in neonates after complicated deliveries. Animal studies have indicated that ultrasound may cause heating of brain tissues. To date, no study has explored brain surface heating by ultrasound during clinically relevant exposure. Hence, we investigated heating effects of B-mode and pulsed Doppler (PD) mode on ex vivo lamb brains using thermography. Five brains were scanned for 5 min in B-mode or for 3 min, 1 min, 30 s or 15 s in PD mode. Brain surface temperature was measured pre- and post-exposure using thermography. The highest mean temperature increase was recorded by B-mode (3.82 ± 0.43°C). All five PD exposure protocols were associated with surface temperature increases of 2.1-2.7°C. These outcomes highlight for the first time that B-mode ultrasound can contribute to brain surface heating during a routine cranial scan. Scan duration should be minimised whenever possible.
authors.affiliation: Department of Medical Imaging and Radiation Sciences, School of Biomedical Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia. Electronic address: Michal.schneider@monash.edu.
authors.forename: Michal E
authors.initials: ME
authors.lastname: Schneider
authors.affiliation: Department of Medical Imaging and Radiation Sciences, School of Biomedical Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Lombardo
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001831:Body Temperature / Q000528:radiation effects*; D001921:Brain / Q000503:physiopathology* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D066298:In Vitro Techniques; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D013817:Thermography / Q000379:methods*; D000069453:Ultrasonic Waves / Q000009:adverse effects*; D014463:Ultrasonography / Q000009:adverse effects*
keywords: Cranial ultrasound; Heating; Newborn; Thermal effects