When to perform CTA in patients suspected of PE?

Venous thromboembolic disease (VTE) is a common disorder which may be associated with high morbidity or mortality when left untreated. Specific VTE diagnosis is mandatory, as treatment is associated with significant side effects. Therefore, timely diagnostic tests are necessary to establish the presence or absence of VTE. Computed tomographic pulmonary angiography (CTPA) has reached a high accuracy in the evaluation of pulmonary embolism (PE). Unfortunately, the continuous decrease of the prevalence of PE in the most recent studies can lead to cost-efficacy imbalance and overuse of ionizing radiation when CTPA is used as a single test. Therefore, no single non-invasive test is suitable for all patients and diagnostic strategies based on sequential non-invasive tests are likely to identify patients in whom anticoagulation can be withheld safely and limit the number of patients requiring more invasive or more expensive tests. The cost effectiveness of clinical stratification and D-dimer test has been demonstrated as it reduces the requirement for invasive tests. In this paper, the current role of CTPA in the diagnosis of PE will be reviewed.