Bottom line: A diagnostic strategy combining clinical assessment, d-dimer, ultrasonography, and lung scan can provide a noninvasive diagnosis before conducting a CT scan can provide a diagnosis in a majority of outpatients with suspected PE.
Summary: Noninvasive diagnosis of pulmonary embolism. Chest. 2011 (June); 139 (6): 1294-1298.
Investigators designed a diagnostic algorithm that included clinical probability assessment, plasma D-dimer testing, sequential testing to include lower limb venous compression ultrasonography, ventilation perfusion lung scan, and chest CT.
Study included 321 consecutive patients presenting at a university hospital with clinically suspected PE and positive d-dimer or high clinical probability (Well’s Criteria.) RESULTS: Diagnosis was established by ultrasonography detection of DVT for 43 (13%) and by lung scan associated with clinical probability in 243 (76%). Chest CT was required in only 35 (11%) of the patients. The 3-month thromboembolic risk in patients not given anticoagulants, based on the results of the diagnostic protocol, was 0.53%, similar to the rate when invasive angiography rules out PE (Brett AS. Journal Watch General Medicine. June 21, 2011.)