**1.4.6 Computed tomography, Multidetector Computed Tomography (MDCT)**

The MDCT is a non-invasive approach, replacing angiography without the need of central venous access. It has a sensitivity of 83% and specificity of 96%. The negative predictive value of MDCT for PE is 89% in the intermediate and 96% in the low clinical risk groups. The cost-benefit and cost-life ratio increases significantly with the combination of MDCT and D-dimer assessment (Perrier et al., 2004; van Belle et al., 2006). With MDCT imaging one can visualise pulmonary vasculature up to the segmental level. An MDCT result showing a PE up to the segmental level could be taken as firm evidence (Eyer et al., 2005; Brunot et al., 2005; Righini et al., 2008; Ghaye et al., 2001; Perrier et al., 2004).

Fig. 1. Computed tomography image of acute pulmonary embolism. (From authors own collection. A: aorta, TP: pulmonary trunk, F: thoracic effusion, Thr: clot)
