Pulmonary Embolic Disease

Pulmonary emboli (PE) range from asymptomatic to life-threatening and are a common source of clinical concern in patients presenting with chest pain and dyspnea. CT using a PE protocol has become the standard for the evaluation of this condition. CT findings include intraluminal filling defects, parenchymal changes of infarction and potentially signs of right heart strain. These must be distinguished from well-known artifacts, most notably bolus-related and motion artifacts. Signs of acute PE must also be distinguished from those related to chronic PE, septic emboli, tumor emboli, chemical emboli and intraarterial thrombi. MR and nuclear studies may be useful in certain patients (e.g, young and those with allergies to iodinated contrast) and in those with certain suspected conditions (such as primary pulmonary arterial tumors or macroscopic tumor emboli).