Clinically suspected pulmonary embolism: Use of bilateral lower extremity US as the initial examination - A prospective study

PURPOSE: To determine the prevalence of deep venous thrombosis (DVT) and ev aluate the use of symptoms and risk factors as selection criteria in the pa tient population undergoing lower extremity ultrasonography (US) as an init ial examination for suspected pulmonary embolism (PE). MATERIALS AND METHODS: One hundred eighty-two consecutive patients referred for bilateral lower extremity US as the first examination for suspected PE were evaluated prospectively for predisposing factors and symptoms of DVT. Patients were placed into four groups: group 1, no symptoms or risk factor s; group 2, both symptoms and risk factors; group 3, only risk factors; gro up 4, only symptoms. The prevalence of DVT detected at lower extremity US i n each group was determined. RESULTS: There were 89 patients in group 1, 12 in group 2, 43 in group 3, a nd 38 in group 4, with a DVT prevalence of 0%, 25%, 14%, and 24%, respectiv ely. There was no significant difference in DVT prevalence between groups w ith symptoms or risk factors but a significant difference between these gro ups and the group lacking both symptoms and risk factors. CONCLUSION: Lower extremity US as the initial examination in patients suspe cted of having PE should be used only in those patients who have symptoms o r risk factors for DVT. This would substantially decrease the number of exa minations performed without a decline in DVT detection.