Pitfalls in the Diagnosis of Acute Pulmonary Embolism on Computed Tomography: Common Pathologic and Imaging Mimics

Purpose of Review: Acute pulmonary embolism (PE) is the third most-common acute cardiovascular disease in the United States. Nearly 900,000 new diagnoses are made each year, with 250,000 associated hospitalizations and up to 100,000 deaths (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Metter et al. in Am J Roentgenol 208(3):489–494, 2017; Jaff et al. in Circulation 123(16):1788–830, 2011). Timely and accurate diagnosis of acute PE is crucial for the prevention of most deaths associated with PE, even more so than optimal medical therapy (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Jaff et al. in Circulation 123(16):1788–830, 2011; Raja et al. in Ann Intern Med 163(9):701, 2015). Recent Findings: Computed tomography (CT) has emerged as the primary imaging modality used in the diagnosis of acute PE. Thus, radiologists play a key role in the correct diagnosis of acute PE, and must differentiate this diagnosis from other conditions that mimic the imaging findings of acute PE, as well as from artifacts associated with imaging techniques (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Jaff et al. in Circulation 123(16):1788–830, 2011; Raja et al. in Ann Intern Med 163(9):701, 2015). Understanding how these diagnoses present on CT is necessary for improved patient care. Summary: This article will discuss the diagnosis of acute PE with CT, the diagnosis of diseases that may be mistaken for acute PE, and how to identify imaging artifacts that may be mistaken for an acute PE.