What imaging should you use to diagnose PE?

Based on PIOPED study, patients with high clinical probability of PE and a high-probability V/Q scan had a 95 percent likelihood of having PE. Patients with low clinical probability of PE and a low-probability V/Q scan had only a 4 percent likelihood of having PE.  A normal V/Q scan virtually excluded PE

MRA for isolated subsegmental, segmental, and central or lobar pulmonary embolism has a sensitivity of 40%, 84%, and 100%. Overall sensitivity 77%.

Based on PIOPED II study, CTA was 83% sensitive (those who had a PE had a positive CT) and 96% specific (those who didn’t have PE had a negative CT).