The PE puzzle: Identifying and differentiating mimics of acute and chronic pulmonary embolism on CTPA.

Abstract

Pulmonary embolism (PE) remains a diagnostic challenge due to its nonspecific clinical presentation and overlapping imaging features with a wide array of conditions. Computed tomography pulmonary angiography (CTPA) is the gold standard for diagnosing PE, but technical limitations and mimicking entities may lead to false-positive interpretations. This review highlights key radiologic mimics of acute and chronic PE, grouped into artifacts and slow-flow phenomena, tumoral mimics, pseudo-defects from adjacent structures, and chronic PE mimics. Particular focus is placed on common pitfalls such as motion artifacts, pulmonary artery opacification artifacts, and transient interruption of contrast. We outline distinctive imaging features and offer practical strategies to optimize acquisition protocols and interpretative accuracy, including the use of dual-source CT, ECG-gating, and attenuation-based criteria. Recognizing these mimics is essential to avoid misdiagnosis and ensure appropriate clinical management. This review aims to equip radiologists and trainees with a structured diagnostic framework to improve confidence and accuracy when interpreting CTPA in suspected PE.