Advances and challenges in the emergency diagnosis of pulmonary embolism

Pulmonary embolism (PE) is a common and potentially life-threatening condition for which diagnostic strategies in the emergency department remain challenging. This review provides an updated synthesis of recent advances in PE diagnosis, from pretest probability assessment and D-dimer-guided strategies to imaging selection across settings.

In patients with very low clinical probability, pulmonary embolism can be excluded on clinical criteria alone. For low or intermediate probability, using D-dimer thresholds adjusted to clinical probability, including age adjustment, increases specificity and safely reduces imaging. Simplified diagnostic pathways - probability assessment, D-dimer testing, then imaging only if required - improve efficiency when applied consistently. In imaging, low-dose and low-iodine computed tomography pulmonary angiography preserves diagnostic quality, including in pregnancy-adapted workflows. When it is contraindicated, new ventilation-perfusion scintigraphy techniques and magnetic resonance angiography provides contrast-free alternatives in experienced centers. Tailored diagnostic pathways have also been developed for specific populations - such as pregnancy, chronic lung disease, and cancer.

Over recent years, the rising number of diagnosed events without a reduction in overall mortality - even as case fatality from pulmonary embolism has decreased - suggests overdiagnosis, driven by detection of smaller or clinically marginal emboli. This supports probability-based testing: anchor decisions in pretest probability, apply thresholds adjusted to the pre-test probability, and reserve imaging for patients likely to benefit. The aim is to balance safety, diagnostic yield, and exposure to radiation and iodinated contrast while preserving overall quality of care.