Department of Radiology Technology, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Department of Radiotherapy Technology, School of Allied Medical Sciences, Arak University of Medical Sciences, Arak, Iran.
J Ultrasound Med. 2021 Sep;40(9):1839-1850. doi: 10.1002/jum.15565. Epub 2020 Nov 12.
Although epidemiological studies have failed to show the harmful effects of ultrasound in humans, as a form of energy, ultrasound has the potential to cause bio-effects in tissues. Therefore, clinical guidelines have been established for ultrasound technology related to human safety, which include Thermal (TI) and mechanical (MI) indices. The appropriate TI and MI ranges for embryonic examinations are between 0-1.0 and 0-0.4, respectively. The accepted TI and MI ranges are 0-2.0 and 0-1.9, respectively, for general ultrasound examinations. In addition, the scan duration should be kept as low as possible. Therefore, the present study aimed at evaluating the scan duration, TI, and MI as measures of acoustic output during ultrasound studies.
A cross-sectional descriptive study was conducted for patients undergoing pregnancy checkups, routine checkups, and initial diagnosis ultrasound examinations. Samples were selected from imaging departments of 4 educational hospitals based on convenience sampling and 321 checklists completed by direct observation of ultrasound examinations.
For pregnancy scans, the mean TI and MI were obtained as 0.32 ± 0.27 and 1.15 ± 0.13, respectively. For non-pregnancy examinations, the mean value of TI and MI were 0.30 ± 0.29 and 1.07 ± 0.35, respectively. Therefore, mean TI for pregnancy and non-pregnancy examinations and mean MI for non-pregnancy studies obtained lower than the permitted values, while the mean MI was higher than the permitted level for first trimester of pregnancy. Also, relatively suitable scan durations were seen in reviewed studies.
From this study, it may be concluded that the reported ultrasound scans were safe.
尽管流行病学研究未能显示超声对人体的有害影响，但作为一种能量形式，超声有可能对组织产生生物效应。因此，已经为与人体安全相关的超声技术制定了临床指南，其中包括热（TI）和机械（MI）指数。胚胎检查的适当 TI 和 MI 范围分别为 0-1.0 和 0-0.4。一般超声检查的可接受 TI 和 MI 范围分别为 0-2.0 和 0-1.9。此外，应尽量缩短扫描时间。因此，本研究旨在评估超声研究中的扫描时间、TI 和 MI 作为声输出的度量。
对接受妊娠检查、常规检查和初步诊断超声检查的患者进行了横断面描述性研究。根据便利抽样从 4 所教育医院的影像科选取样本，并通过直接观察超声检查完成了 321 份检查表。
对于妊娠扫描，TI 和 MI 的平均值分别为 0.32±0.27 和 1.15±0.13。对于非妊娠检查，TI 和 MI 的平均值分别为 0.30±0.29 和 1.07±0.35。因此，妊娠和非妊娠检查的平均 TI 以及非妊娠研究的平均 MI 均低于允许值，而妊娠早期的平均 MI 高于允许水平。此外，在回顾的研究中观察到相对合适的扫描时间。
从这项研究中可以得出结论，报告的超声扫描是安全的。
