Miller M W, Brayman A A, Abramowicz J S
Department of Obstetrics and Gynecology, School of Medicine and Dentistry, University of Rochester, New York 14642, USA.
Am J Obstet Gynecol. 1998 Jul;179(1):241-54. doi: 10.1016/s0002-9378(98)70279-0.
We address the issue of health and safety in relation to exposure to diagnostic ultrasound, with particular emphasis given to obstetrics. In terms of fetal and maternal outcomes, the epidemiologic record of diagnostic ultrasound is exemplary but is primarily made on the basis of data derived from clinical devices whose outputs were relatively low compared with what is now allowable and available. The power outputs of clinical devices have been increasing over the past decade such that the potential for thermal and nonthermal insults is increased. For obstetric devices that use these higher outputs, the Food and Drug Administration now requires the presentation of 2 on-screen indexes, the thermal index and the mechanical index, in recognition of the 2 major mechanisms by which ultrasonography is known to affect cells and tissues. Greater responsibility for patient safety is now placed on the diagnostician; for the new indexes to be meaningful the diagnostician must be cognizant of the health and safety implications. The purpose of this article is to provide some guidance to the obstetrician in interpreting the indexes and to review the current status of ultrasonography biophysics in relation to the use of diagnostic ultrasound in obstetrics.
我们探讨了与诊断性超声暴露相关的健康与安全问题，尤其着重于产科领域。就胎儿和母亲的结局而言，诊断性超声的流行病学记录堪称典范，但主要是基于从临床设备获得的数据得出的，这些临床设备的输出功率与现在允许和可用的相比相对较低。在过去十年中，临床设备的功率输出一直在增加，因此热损伤和非热损伤的可能性也增加了。对于使用这些较高输出功率的产科设备，美国食品药品监督管理局现在要求在屏幕上显示两个指标，即热指数和机械指数，以认识到超声检查影响细胞和组织的两种主要机制。现在，诊断医生对患者安全负有更大的责任；为了使新指标有意义，诊断医生必须了解其对健康和安全的影响。本文的目的是为产科医生解读这些指标提供一些指导，并回顾与产科诊断性超声使用相关的超声生物物理学的现状。
