Induction of pulmonary hemorrhage in rats during diagnostic ultrasound.
The induction of pulmonary hemorrhage by pulsed ultrasound was discovered over 20 years ago. This phenomenon may pose a risk of patient lung injury, particularly for point of care pulmonary ultrasound. A diagnostic ultrasound machine (HDI 5000; Philips Healthcare, Andover MA USA) with 7.6 MHz (CL15-7) linear array was used to image the right lung of anesthetized rats in a warmed water bath. The image showed rapid initiation and progression of comet tail artifacts across the lung image for an on-screen mechanical index (MI) of 0.9, which corresponded to a pulmonary hemorrhage in the lung. Groups of rats were scanned at a range of MI settings and a threshold was located at an MI of about 0.44. This finding indicated a greater sensitivity to pulmonary ultrasound than was expected, based on previous results. Further research is needed to understand this phenomenon and to develop safety guidelines for sonographers.
Department of Radiology, University of Michigan Health System, Ann Arbor, MI 48109-5667, USA. douglm@umich.edu
Douglas L
DL
Miller
D000818:Animals; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology*; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000209:etiology*; D051381:Rats; D014463:Ultrasonography / Q000009:adverse effects*