Pulmonary embolism: role of ventilation-perfusion scintigraphy.

The evaluation for pulmonary embolism in the emergency setting has many challenges. Patients often present with symptoms that are nonspecific. Emergency Department physicians utilize their own subjective judgment or objective clinical algorithms, such as the Wells Score to assess the likelihood of the patient having PE. Other techniques, such as D-dimer assays and Doppler ultrasound leg studies for deep venous thrombosis are very useful, as well. Ventilation-perfusion lung scans and computed tomography pulmonary angiography are both available in most institutions. However, factors such as sensitivity or specificity, overnight availability, radiation exposure, and comfort with interpretation criteria play a role in deciding which procedure should be used. Relative merits of both the procedures will be discussed.