Spiral CT for pulmonary embolism: the paradigm has shifted

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 embrace of CT as the new standard of reference for imaging PE, although the actual significance 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. The introduction of multidetector-row spiral CT has greatly improved visualization of peripheral pulmonary arteries and detection of small emboli. Previous concerns regarding the use 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 technology and appears to have surpassed other imaging modalities for the accurate detection of central and peripheral PE. In this review, the authors assess the current role of spiral CT in the diagnostic algorithm of PE.