Canadian Association of Radiologists Recommendations for the Safe Use of MRI During Pregnancy

Abstract

The use of magnetic resonance imaging (MRI) during pregnancy is associated with concerns among patients and health professionals with regards to fetal safety. In this work, the Canadian Association of Radiologists (CAR) Working Group on MRI in Pregnancy presents recommendations for the use of MRI in pregnancy, derived from literature review as well as expert panel opinions and discussions. The working group, which consists of academic subspecialty radiologists and obstetrician-gynaecologists, aimed to provide updated, evidence-based recommendations addressing safety domains related to energy deposition, acoustic noise, and gadolinium-based contrast agent use based on magnetic field strength (1.5T and 3T) and trimester scanned, in addition to the effects of sedative use and occupational exposure.

Lower-limb progressive paraparesis management and diagnosis overview in a pregnant woman with vertebral haemangioma

“…MRI plays a key role in diagnosis and thus far appears to be safe, though its possible side effects are still not ruled out. 11 , 12 A study from Ontario, Canada, 13 revealed that exposure to MRI in the first trimester compared with non-exposure was not associated with an increased risk of harm to the foetus. The theoretical risks of undergoing MRI are biological effects of static and a time-varying magnetic field, the thermal effects associated with radiofrequency exposure and the acoustic noise.…”

“…There are currently no studies demonstrating adverse effects when a pregnant patient is scanned at 1.5 or 3 T in any trimester, but depending on the circumstances, an MRI at 1.5 T or an MRI at 3 T may be recommended. 12 …”

“…There is no evidence of damage to the foetal auditory organs during the first trimester; if clinically necessary, MRI in the first trimester at a field strength of 1.5 T is generally considered safe. 6 , 12 …”

“…No adverse effects were demonstrated in the studies for 1.5 T, while for 3 T MRI we still do not have enough studies for pregnant women; therefore, the use of a 1.5 T device is preferred if both options are available, especially in the first trimester of pregnancy. 12 , 19…”

Clinical advances: pregnancy in gastroenterologic and hepatic conditions

“…However, the joint American College of Radiology and Society for Pediatric Radiology 2020 practice parameters states that currently available data do not conclusively indicate adverse effects of MRI in pregnancy at either field strength and no special considerations are recommended for any pregnancy trimester and MRI scans may be performed assuming the risk benefit ratio supports the indication 26. In contrast, the Canadian association of radiologist recommend that 1.5 T is preferred if both field strengths are available 27…”