Multidetector computed tomography for the diagnosis of acute pulmonary embolism

Purpose of review This review describes the accuracy of multidetector contrast-enhanced computed tomography (CT) for the diagnosis of acute pulmonary embolism, the role of clinical assessment and of venous phase imaging in combination with it, and the approach to the diagnosis. Recent findings The sensitivity of CT angiography was 83%, specificity 96% and positive predictive value 86%. Positive predictive values were 97% for pulmonary embolism in a main or lobar artery, 68% for a segmental vessel, and 25% for a subsegmental branch. A CT angiograrn with concordant clinical probability assessment resulted in high predictive values, but with a discordant clinical probability, predictive value was low. The sensitivity for pulmonary embolism increased to 90% by using CT venography in combination with CT angiography. A negative D-dimer by the rapid enzyme-linked immunosorbent assay method with a low or moderate probability clinical assessment can safely exclude pulmonary embolism. Clinical probability assessment and D-dimer are recommended. In general, CT angiography in combination with CT venography is recommended, but the choice of diagnostic tests depends on the clinical situation. Summary The reliability of multislice CT angiography is enhanced by clinical assessment and CT venography used with it. Clinical assessment and D-dimer are recommended before imaging.