By obstruction of the pulmonary vascular bed acute pulmonary embolism (APE) leads to right heart dysfunction with a broad spectrum of clinical deteroration ranging from an even asymptomatic presentation to a fatal course with immediate death. Depending on hemodynamic stability and early therapeutic anticoagulation mortality ranges between 1 and 4% in hemodynamic stable and anticoagulated patients, and up to 80% in hemodynamic unstable patients without anticoagulation. Anticoagulation can reduce mortality effectively up to 80%. Prompt diagnostic assessment and therapy are essential due to the risk of re-embolization and rapid decrease of right ventricular function especially during the first few hours after APE onset. Necropsy studies reveal that APE is a common cause of death in hospitalized patients and that clinical diagnosis of APE often is difficult. The clinical symptoms as the routinely available diagnostic tests like ECG, chest X-ray and analysis of arterial blood gases cannot be relied on due to nonspecific alterations. The use of standardized probability tests, like the Wells score or the revised Geneva score allows to categorize the pretest probability of APE before further diagnostic evaluation [9]. The assessment of these prediction rules has become a key step in all diagnostic algorithms for APE [7]. Also, the interpretation of thoracic imaging tests depends on the pretest probability. According to the PIOPED studies [5, 6] computed tomography pulmonary angiography (CTPA) has become the method of choice for imaging the pulmonary vascular bed. To date, hemodynamically stable patients are treated with anticoagulation and hemodynamically unstable patients receive anticoagulation plus thrombolysis or alternatively embolectomy. There is no consensus for the appropriate management of hemodynamically stable patients with increased mortality due to right ventricular dysfunction. However, all patients should be treated with anticoagulants for at least 3 months, and patients with unprovoked APE and low risk of bleeding should be considered for long-term anticoagulation [7].