CT imaging of pulmonary artery aneurysms in the emergency department - What you need to know.

Pulmonary artery (PA) aneurysms are rare vascular abnormalities with potentially life-threatening complications such as rupture, massive hemoptysis, and pulmonary infarction. These conditions are often asymptomatic and incidentally detected but can present with nonspecific symptoms like cough, dyspnea, or hemoptysis in an emergency setting. Multidetector CT pulmonary angiography (CTPA) has outshone traditional angiography, supplemented by advanced 3D post-processing techniques such as maximum intensity projection (MIP), volumetric rendering (VR), and cinematic rendering (CR) techniques, playing a pivotal role in diagnosis and management of PA aneurysms. This pictorial essay reviews eight cases of PA aneurysms and pseudoaneurysms, exploring their diverse etiologies, imaging findings, and the application of 3D imaging to enhance diagnostic confidence and procedural planning. Through these cases, we highlight the critical role of advanced imaging and post-processing reconstructions in the timely identification and treatment of these rare but high-risk vascular entities in the emergency setting.