Imaging of Acute Pulmonary Embolism

The past decade has seen a shift in the imaging paradigm for acute pulmonary embolism (PE) from a combination of clinical acumen, ventilation-perfusion scintigraphy, and conventional pulmonary angiography to computed tomographic pulmonary angiography (CTPA). The ability to perform CT rapidly with direct visualization of thrombi allows for rapid and reliable diagnosis or exclusion of PE in the vast majority of cases. In the same setting, CT can provide information on right heart function, offer an evaluation of the deep venous system through indirect CT venography, as well as allow for the detection of alternative diagnoses that may account for the patient’s symptoms. Published experience with CTPA has established that a negative result reliably excludes clinically significant PE in more than 98% of cases. As a result, CT has become the preferred first-line imaging test in the evaluation of suspected acute PE.