作者: Diane Dalecki , Carol H. Raeman , Sally Z. Child , Edwin L. Carstensen
DOI: 10.1016/0301-5629(95)00041-O
关键词: Ultrasound exposure 、 Ultrasound 、 Pulse duration 、 Pulse repetition frequency 、 Medicine 、 Pulsed Ultrasound 、 Intestinal Hemorrhage 、 Irradiation 、 Frequency dependence 、 Pathology 、 Nuclear medicine
摘要: Threshold exposures for producing intestinal hemorrhage in mice were determined using focused sources operating at 0.7, 1.1, 2.4 and 3.6 MHz. The choice of pulse length (10 μs) repetition frequency (100 Hz) made the diagnostically relevant, while same time, minimized possible thermal contributions to mechanism action ultrasound. Each animal was irradiated four five abdominal sites 5 min per site. Suprathreshold lesions ranged from small petechiae hemorrhagic regions extending 4 mm or more along intestine, depending upon exposure levels. Higher frequencies less effective than lower frequencies. Thermocouple measurements temperature rise intestine during ultrasound revealed increments between 1° 2°C highest dependence production together with observed limited heating is consistent a cavitation-related pulsed