Multidetector-row computed tomography in suspected pulmonary embolism

N Engl J Med. 2005 Apr 28;352(17):1760-8. doi: 10.1056/NEJMoa042905.


Background: Single-detector-row computed tomography (CT) has a low sensitivity for pulmonary embolism and must be combined with venous-compression ultrasonography of the lower limbs. We evaluated whether the use of D-dimer measurement and multidetector-row CT, without lower-limb ultrasonography, might safely rule out pulmonary embolism.

Methods: We included 756 consecutive patients with clinically suspected pulmonary embolism from the emergency departments of three teaching hospitals and managed their cases according to a standardized sequential diagnostic strategy. All patients were followed for three months.

Results: Pulmonary embolism was detected in 194 of the 756 patients (26 percent). Among the 82 patients with a high clinical probability of pulmonary embolism, multidetector-row CT showed pulmonary embolism in 78, and 1 patient had proximal deep venous thrombosis and a CT scan that was negative for pulmonary embolism. Of the 674 patients without a high probability of pulmonary embolism, 232 (34 percent) had a negative D-dimer assay and an uneventful follow-up; CT showed pulmonary embolism in 109 patients. CT and ultrasonography were negative in 318 patients, of whom 3 had a definite thromboembolic event and 2 died of possible pulmonary embolism during follow-up (three-month risk of thromboembolism, 1.7 percent; 95 percent confidence interval, 0.7 to 3.9). Two patients had proximal deep venous thrombosis and a negative CT scan (risk, 0.6 percent; 95 percent confidence interval, 0.2 to 2.2). The overall three-month risk of thromboembolism in patients without pulmonary embolism would have been 1.5 percent (95 percent confidence interval, 0.8 to 3.0) if the D-dimer assay and multidetector-row CT had been the only tests used to rule out pulmonary embolism and ultrasonography had not been performed.

Conclusions: Our data indicate the potential clinical use of a diagnostic strategy for ruling out pulmonary embolism on the basis of D-dimer testing and multidetector-row CT without lower-limb ultrasonography. A larger outcome study is needed before this approach can be adopted.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anticoagulants / therapeutic use
  • Female
  • Femoral Vein / diagnostic imaging
  • Fibrin Fibrinogen Degradation Products / analysis*
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Popliteal Vein / diagnostic imaging
  • Predictive Value of Tests
  • Prospective Studies
  • Pulmonary Artery / diagnostic imaging
  • Pulmonary Embolism / diagnosis
  • Pulmonary Embolism / diagnostic imaging*
  • Pulmonary Embolism / etiology
  • Thromboembolism / diagnosis
  • Tomography, X-Ray Computed / methods*
  • Ultrasonography
  • Venous Thrombosis / complications
  • Venous Thrombosis / diagnostic imaging*


  • Anticoagulants
  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D