Pulmonary embolism: diagnosis with contrast-enhanced electron-beam CT and comparison with pulmonary angiography

To determine the sensitivity and specificity of contrast material-enhanced electron-beam computed tomography (CT) in the diagnosis of pulmonary embolism (PE).

Sixty patients suspected of having PE were prospectively evaluated with pulmonary angiography and contrast-enhanced electron-beam CT. Thirty-eight patients underwent ventilation-perfusion (V-P [also known as V/Q]) scanning. The pulmonary vasculature was divided into 12 anatomic zones. CT and angiographic findings were correlated on a patient-by-patient basis and for each vascular zone.

Both studies were negative for PE in 36 patients. Both studies were positive in 15 patients, with the site of the emboli correlating well. Prospective sensitivity of CT was 65%; specificity, 97%; positive predictive value, 94%; and negative predictive value, 82%. After review of the nine discordant cases, sensitivity and specificity approached 100% for clinically important acute PE. CT depicted central and peripheral emboli equally well. CT was more sensitive and specific than V-P scanning.

Electron-beam CT is a sensitive and specific noninvasive method for the diagnosis of PE. It has the potential to replace V-P scanning as the primary screening examination for PE.