Can you tell me in a pregnant patient in whom the diagnosis of pulmonary embolism (pe) must be excluded?

Evidence: PE must be excluded in anyone (pregnant or not) in whom it is suspected. The symptoms are breathlessness (tricky, because pregnancy causes breathlessness), rapid respirations, rapid heart rate, rarely passing out, rarely pain with breathing, low oxygen level, swollen legs (tricky, because pregnancy causes swollen legs). Pregnancy is a risk factor for PE. Dx requires CT with lots of radiation.