Safety of diagnostic imaging in pregnancy. Part 2: magnetic resonance imaging, ultrasound scanning and Doppler assessment

Abstract

Key content:• There is a widespread lack of understanding among clinicians regarding the potential risks of magnetic resonance imaging (MRI) and ultrasound energy on the fetus. • The use of MRI is not generally advisable during the first trimester of pregnancy.• Concerns exist regarding the potential thermal and mechanical effects of ultrasound on the developing embryo/fetus. • The use of Doppler ultrasound in the first trimester should be restricted to well-defined diagnostic purposes with the shortest possible exposure duration. Learning objectives:• To understand the safety issues of MRI and ultrasound scanning.• To understand the potential mechanical and thermal effects of Doppler ultrasound at various stages of pregnancy. • To be able to provide women with accurate information about the safety of MRI and ultrasound scanning. Ethical issues:• Clinicians should be aware of and trained in the safety issues concerning the use of MRI and ultrasound scans in relation to the stages of pregnancy.Keywords acoustic noise / four-dimensional ultrasound / mechanical effects / thermal effects / three-dimensional ultrasoundPlease cite this article as: Eskandar OS, Eckford SD, Watkinson T. Safety of diagnostic imaging in pregnancy. Part 2: magnetic resonance imaging, ultrasound scanning and Doppler assessment.

Decision Making Processes for a Pregnant Woman Admitted to the Accident and Emergency Department Requiring Emergency Diagnostic X-ray – A Case Study

“…Doses for the same procedures vary widely between patients and hospitals. However, the absorbed dose of the embryo or the fetus where the X-ray beam does not directly irradiate them, such as maternal skull or chest X-ray, is extremely low therefore, the further the target area from the embryo or fetus, the less the exposure and risk of radiation and vice versa (Eskandar et al 2010). The American college of obstetrics and gynecology (Acog) states that exposure to <5 rads is not associated with an increase in fetal anomalies or pregnancy loss.…”

“…The purpose is to make a world view on how a sound decision-making is demonstrated in a fast-paced environment. BAckgrouND X-ray is a form of electromagnetic radiation with very high frequency and energy (Eskandar et al 2010), with a wavelength shorter so as to have a fairly high permeability of the material. Therefore, X-rays can be used as diagnostic and therapeutic management in medical radiology.…”

“…Protection procedure aims to prevent the occurrence of deterministic effects in individuals by keeping doses below the threshold and to minimize the risk of stochastic effects (Eskandar et al 2010). Thousands of pregnant patients and medical radiation workers are exposed to radiation each year.…”

“…The accepted background cumulative dose of ionising radiation during pregnancy is 5 rad (50 mgy) which is much more than the exposure dose of most of the diagnostic radiological examinations (Eskandar et al 2010). The risk of microcephaly and severe mental retardation with high exposure begins at 10 weeks of gestation.…”

“…Nevertheless, until more data are available delineating potential fetal risk, it is prudent Table 1. Possible effects of acute doses of radiation and estimated threshold doses (Eskandar et al 2010 to delay non-urgent radiographs during the sensitive period of 10-17 weeks of gestation. Table 1 highlights the possible effects of X-ray to pregnancy in accordance to its gestationional age.…”