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Pulmonary embolus (PE) occurs when a clot from a vein, originating in the venous sinuses of the calf or the femoral vein or the pelvis, detaches and becomes lodged in the pulmonary arterial tree (1).
Occasionally the right side of the heart is a source of a pulmonary embolus.
Deep vein thrombosis (DVT) is the formation of blood clots in deep veins of the legs (1). In a majority of patients, PE is a consequence of DVT (2)
Venous thromboembolism (VTE) is the term used to describe a thrombus in a vein which may detach from the site of origin and travel through blood to a distant site, a phenomenon called embolism (1). PE and DVT represent different clinical manifestations of VTE (2).
An estimated 12-36% of patients with PE are misdiagnosed during initial evaluation in emergency departments or primary care clinic (4)
Non thrombotic pulmonary emboli are rare. Causes include:
Computed tomography pulmonary angiogram (CTPA) scan