Clinically suspected pulmonary embolism: use of bilateral lower extremity US as the initial examination--a prospective study.
OBJECTIVE
To determine the prevalence of deep venous thrombosis (DVT) and evaluate the use of symptoms and risk factors as selection criteria in the patient population undergoing lower extremity ultrasonography (US) as an initial examination for suspected pulmonary embolism (PE).


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 factors; group 2, both symptoms and risk factors; group 3, only risk factors; group 4, only symptoms. The prevalence of DVT detected at lower extremity US in each group was determined.


RESULTS
There were 89 patients in group 1, 12 in group 2, 43 in group 3, and 38 in group 4, with a DVT prevalence of 0%, 25%, 14%, and 24%, respectively. There was no significant difference in DVT prevalence between groups with symptoms or risk factors but a significant difference between these groups and the group lacking both symptoms and risk factors.


CONCLUSIONS
Lower extremity US as the initial examination in patients suspected of having PE should be used only in those patients who have symptoms or risk factors for DVT. This would substantially decrease the number of examinations performed without a decline in DVT detection.
Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA. rsheiman@caregroup.harvard.edu
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Sheiman
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McArdle
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012307:Risk Factors; D013924:Thrombophlebitis / Q000000981:diagnostic imaging*; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex