Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) syndrome is a rare congenital coronary artery anomaly. There are two types of ALCAPA syndrome: the infant type and the adult type, each of which has different manifestations and outcomes. Infants experience myocardial infarction and congestive heart failure, and approximately 90% die within the 1st year of life. Rarely, ALCAPA syndrome manifests in adults; it may be an important cause of sudden cardiac death. Historically, ALCAPA syndrome was diagnosed at conventional angiography. However, the development of electrogardiographically gated multidetector computed tomographic (CT) angiography and magnetic resonance (MR) imaging enables accurate noninvasive imaging. At MR imaging and multidetector CT angiography, findings include direct visualization of the left coronary artery arising from the main pulmonary artery. Reversed flow from the left coronary artery into the main pulmonary artery may be seen at steady-state free-precession cine and fast cine phase-contrast MR imaging. Because of its ability to assess myocardial viability, which can be used as a prognostic factor to direct the need for surgical repair, MR imaging plays an important role in patient treatment. Restoration of a dual-coronary-artery system is the ideal surgical treatment for ALCAPA syndrome.

Pulmonary artery aneurysms and pseudoaneurysms are uncommon. Most are caused by trauma, often iatrogenic, infection, and Behçet's syndrome. Less common causes include pulmonary hypertension, congenital heart disease, neoplasms, and connective tissue disease. Recognition of pulmonary artery aneurysms and pseudoaneurysms is important because of the high morbidity and mortality rates of rupture.

Coronary artery anomalies constitute a diverse group of abnormalities, ranging from anatomic variants to those having hemodynamic consequences. This review focuses on major anomalies that have clinical implications requiring treatment, including anomalous origin of the coronary artery from the opposite sinus with interarterial course specifically with an intramural course, coronary artery origin from the pulmonary artery, and coronary artery fistula. Comprehensive imaging evaluation is necessary to precisely delineate the anatomy as well as pathophysiologic aspects of the anomaly before determining treatment options for a specific patient. Coronary computed tomographic angiography provides elegant depiction of coronary arterial anatomy and the relationship of the vessel to the adjacent structures, with the ability to perform three-dimensional reconstructions. Magnetic resonance (MR) imaging is emerging as an alternative noninvasive imaging strategy, particularly in young individuals, due to the lack of ionizing radiation and avoidance of iodinated contrast agents. This review describes the roles and recent technical advancements in computed tomography and MR imaging pertinent to coronary artery imaging. Additionally, this article will familiarize readers with the cross-sectional imaging appearance of clinically relevant coronary anomalies, hemodynamic considerations, and complex decision making. The different management strategies used for these anomalies, such as coronary unroofing, reimplantation, bypass grafting, Takeuchi repair, and surgical and interventional closure of fistulas, as well as specific posttreatment complications, are also discussed. RSNA, 2017.