Imaging in Pregnant Patients: Examination Appropriateness

Abstract

A recurring source of contention between clinicians and radiologists continues to be examination appropriateness when imaging pregnant patients. With the multitude of references on potential radiation risks to the fetus, radiologists tend to be cautious and hesitant about exposing the fetus to radiation. This tendency is often interpreted by referring physicians as intrusion into and delay in the care of their patients. The risk burden of radiation exposure to the fetus has to be carefully weighed against the benefits of obtaining a critical diagnosis quickly and using a single tailored imaging study. In general, there is lower than expected awareness of radiation risks to the fetus from imaging pregnant patients. Modalities that do not use ionizing radiation, such as ultrasonography and magnetic resonance imaging, should be the preferred examinations for evaluating an acute condition in a pregnant patient. However, no examination should be withheld when an important clinical diagnosis is under consideration. Exposure to ionizing radiation may be unavoidable, but there is no evidence to suggest that the risk to the fetus after a single imaging study and an interventional procedure is significant. All efforts should be made to minimize the exposure, with consideration of the risk versus benefit for a given clinical scenario.

Grossesse et risques d’irradiations en radiodiagnostic : état des connaissances des usagers au CHU de Yopougon (Abidjan, Côte d’Ivoire)

“…Une comparaison entre les niveaux de dose associée à chacun de ces risques et les doses estimées à partir du foetus des examens radiologiques permettrait de conclure que les risques sont minimes et par conséquent, les examens radiologiques de médecine nucléaire qui peuvent fournir d'importantes informations de diagnostic ne doivent pas être retenu sur les femmes enceintes. Il nous apparaît donc nécessaire, voire indispensable, de substituer un examen radiologique utilisant des rayons X par des examens tout aussi efficaces voire plus performants mais non irradiants tels que l'échographie couplée au Doppler couleur et l'imagerie par résonance magnétique (IRM) chez la femme enceinte (Wieseler et al, 2010). Dans notre étude, une proportion très importante des médecins prescripteurs interrogés (de 52 à 63,7 %) ne savaient pas faire cette substitution.…”

Aspectos atuais em imagenologia na gestação

“…As doses de exposição fetal no exame de tomografia dependem da topografia do estudo radiológico em relação ao útero 15 (Figura 3).…”

“…Neles, a radiação ionizante é substituída pelo uso de ondas sonoras, no caso da USG, ou por um campo eletromagnético, na RNM 10,15 .…”

“…Estudos recentes mostram que o ruído acústico gerado durante o exame é atenuado pelo líquido amniótico e chega ao feto com menos de 30 dB, o que torna a lesão acústica menos provável 15 .…”

“…A RNM tem sido utilizada para avaliação de doenças obstétri-cas e fetais por mais de 20 anos sem evidência de efeitos prejudiciais ao feto 15 . Apesar de a segurança a longo prazo da ressonância magnética não ter sido totalmente estabelecida, acredita-se que, em geral, o benefício proporcionado por ela na avaliação fetal supere de longe qualquer risco teórico 1 .…”