Diagnosis of pulmonary embolism

The methods and strategy of the diagnosis of pulmonary embolism (PE) are reviewed. Pulmonary thromboembolic disease includes every condition in which the obstruction of pulmonary arteries by thrombi is observed. These emboli are usually the result of deep venous thrombosis of the lower extremities. Despite the progress made in the diagnostic methods of PE, in many cases diagnosis is delayed or missed. Thus, deep venous thrombosis and pulmonary embolism remain a frequent cause of morbidity and mortality. In order to avoid invasive methods in diagnosis of PE (i.e. pulmonary angiography), because of its high morbidity and mortality, many noninvasive methods have been developed. The technological and medical advances in diagnosis of deep venous thrombosis and pulmonary embolism by noninvasive methods deserve emphasis. Among the innovations are Doppler examination of venous blood flow, impedance plethysmography, phleborheography, radioisotope tagging of thrombi and real-time B-mode ultrasonography of the veins. In addition, progress has been made in the identification of pulmonary emboli with ventilation-perfusion scanning, computed tomography (CT) and magnetic resonance imaging (MRI). Finally, a plan of strategy for the identification of pulmonary emboli is proposed.