Article Text

Download PDFPDF

Helical computed tomography (CT) is safe as the primary diagnostic test in suspected pulmonary embolism (PE)
  1. A Sathyapala
  1. asathyapala{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Five hundred and ten patients with suspected PE underwent helical CT of the pulmonary arteries within 24 hours of presentation. If the CT scan was normal or inconclusive, lower limb ultrasonography was performed that day and on days 4 and 7. All patients were treated appropriately and followed up for 3 months.

Helical CT identified PE in 124 of 510 patients (24.3%). Of the 378 scans which did not show PE, 248 were normal while 130 identified an alternative diagnosis. Two of these 378 patients were found to have DVT on ultrasound that same day. The other 376 patients (who were not anticoagulated) had a 3 month thromboembolism rate of 0.8% (three of 376). If CT alone had been performed, the thromboembolism rate in those whose CT scan did not show PE would have been 1.3%. These rates are comparable to those after normal V/Q scans and normal pulmonary angiograms. Of the 246 patients who had a completely normal CT scan and normal ultrasound, only one had a confirmed PE over 3 months, giving this algorithm a false negative rate of 0.4% and a sensitivity of 99.6%.

Helical CT appears to be sufficient as the primary diagnostic tool for PE, becoming even more sensitive with ultrasonography. It also has the advantage of providing an alternative diagnosis for symptoms in 25% of patients. However, this study does not take into account the costs or hazards of CT scanning, nor does it incorporate such other tests as d-dimer estimation.

View Abstract