Diagnosing pulmonary embolism: time to rewrite the textbooks.

Computed tomography (CT) is rapidly becoming the first line modality for imaging pulmonary embolism (PE). However, limitations for the accurate diagnosis of small peripheral emboli have prevented the unanimous acceptance of CT as the new standard of reference for imaging PE although the actual significance of the detection and treatment of isolated peripheral emboli is uncertain. At the same time the high negative predictive value of CT pulmonary angiography for excluding clinically significant PE has been established in retrospective and prospective studies. The introduction of multidetector-row spiral CT has greatly improved visualization of peripheral pulmonary arteries and detection of small emboli. Previous concerns regarding the accuracy of spiral CT for the accurate diagnosis of peripheral pulmonary emboli should thus be overcome. Multidetector-row spiral CT has become a widely available and cost-effective modality, which has surpassed other imaging modalities for PE diagnosis to a point where over-utilization may become of concern. Our most immediate goal must be to educate our referring colleagues about these important transitions so that the diagnostic algorithm in patients with suspected acute PE is updated to accurately reflect our current diagnostic prowess in medical imaging.