C. Ventilation-perfusion scanning exposes the fetus to less radiation than computed tomographic pulmonary angiography – Explanation
Pregnancy: DVT/PE investigation
Guidelines were updated in 2010 by the Royal College of Obstetricians. Key points include:
- chest x-ray should be performed in all patients
– compression duplex Doppler should be performed if the chest x-ray is normal – this may provide
indirect evidence of a pulmonary embolism and negate the need for further radiation exposure - the decision to perform a V/Q or CTPA should be taken at a local level after discussion with the
patient and radiologist
Comparing CTPA to V/Q scanning in pregnancy
| CTPA | V/Q scanning |
| CTPA slightly increases the lifetime risk of maternal breast cancer (increased by up to 13.6%, background risk of 1/200 for study population). Pregnancy makes breast tissue particularly sensitive to the effects of radiation |
V/Q scanning carries a slightly increased risk of childhood cancercompared with CTPA (1/280,000 versus less than 1/1,000,000)D-dimer is of limited use in the investigation of thromboembolism as it often raised in pregnancy. |
D-dimer is of limited use in the investigation of thromboembolism as it often raised in pregnancy.
