The Many Faces of Nonthrombotic Pulmonary Artery Embolism

Nonthrombotic pulmonary artery embolism (NTPE) involves occlusion of pulmonary arteries by nonthrombotic material, such as septic emboli, tumor cells, fat, air, or foreign substances. NTPE is less common than thrombotic pulmonary embolism (PE) and may be misdiagnosed as PE. Although the clinical manifestation mimics that of PE, NTPE has distinct pathophysiologic mechanisms that necessitate different management. Diagnosis requires a high index of clinical suspicion and knowledge of imaging findings. The authors provide an overview of the various causes of NTPE, including infectious, neoplastic, iatrogenic or exogenous, and miscellaneous entities, and highlight their key imaging findings. Early and accurate diagnosis is essential for appropriate management. ^©RSNA, 2026.