So while they couldn t think of anything else, it turned out to be something else. So this is not a disease that we are very good at diagnosing based on our clinical judgment. Remember also that fewer than one-third of the patients with pulmonary embolism in the study had symptoms of DVT, so that didn t help much. The majority of cases who turned out to have pulmonary embolism had no symptoms or signs of deep venous thrombosis. So the symptoms that we look for to tell us that someone may be having a coronary are not terribly sensitive.
Patients can have disease.
And Doppler ultrasound. I ll explain that in a second. And then its accuracy is less in asymptomatic patients. But the particular point about Doppler ultrasonography that you need to keep in mind is that it has difficulty it s not a useful test particularly in patients who have had prior deep venous thrombosis. Doppler studies remain positive really indefinitely in patients who have prior clotting.