The Risk of Exposure to Diagnostic Ultrasound in Postnatal Subjects

摘要: This review examines the nonthermal physical mechanisms by which ultrasound can harm tissue in postnatal patients. First nature of more significant interactions between and is described, followed an examination existing literature with particular emphasis on pressure thresholds for potential adverse effects. The interaction ultrasonic fields depends a fundamental way whether naturally contains undissolved gas under normal physiologic conditions. Examples gas-containing tissues are lung intestine. Considerable effort has been devoted to investigating acoustic parameters relevant threshold extent hemorrhage. Thresholds as low 0.4 MPa at 1 MHz have reported. situation intestinal damage similar, although appears be somewhat higher. For other tissues, auditory stimulation or tactile perception may occur, if rarely, during exposure diagnostic ultrasound; similar lower intensities used therapeutically accelerate healing bone fractures. At levels ultrasound, there no consistent evidence effects that not known contain stabilized bodies. Although modest occur certain identifiable applications, risk induction biological effect mechanism due extremely small.