Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, typically in the lower extremities. Pulmonary embolism (PE) occurs when a DVT clot (or fragment) breaks free and travels through the heart to the pulmonary arteries (having to do with the lungs) and lodges in an artery causing a partial or complete blockage. Together DVT and PE comprise venous thromboembolism (VTE), a major public health problem in the United States. PE is associated with a high short-term mortality, requiring a timely and accurate diagnosis for the initiation of antithrombotic therapy. PE is difficult to diagnose due to the non-specific signs and symptoms patients have with this condition such as a cough, shortness of breath, tachycardia, hypoxia and hemoptysis.