Pulmonary embolism - Investigations

- There have been concerns over the safety of iodinated contrast medium with CTPA, as this can potentially alter fetal or neonatal thyroid function. 

Current European guidelines indicate that iodinated contrast media may be given to a pregnant woman when radiographic examination is essential and that, following administration of iodinated agents to the mother during pregnancy, thyroid function should be checked in the neonate 

- Pulmonary angiography carries the highest radiation exposure 
(at least 0.5 mSv to the fetus and 5–30 mSv to the mother)

- Breast tissue is especially sensitive to radiation exposure during pregnancy and it therefore seems sensible to recommend that lung perfusion scans should be considered the investigation of first choice for young women, especially if there is a family history of breast cancer or the woman has had a previous chest CT scan