Images in cardivascular medicine. Detection of large aneurysm of Vieussens' arterial ring after abnormal shadow on chest radiography.

A 73-year-old woman presented to our institution with an abnormal shadow on chest radiography. The patient was a nonsmoker and enjoyed good past health. There were no constitutional symptoms. She was completely asymptomatic during exercise and at rest. An ECG (Figure 1) showed normal sinus rhythm. A posteroanterior view of the chest radiograph (Figure 2) showed a well-circumscribed roundish mass at the left heart border. A lateral chest radiograph (Figure 3) suggested a more anterior-located abnormality. An echocardiogram was performed to delineate the relationship of the mass and the adjacent cardiac structure. It showed a large vascular structure anterior to the main pulmonary artery and continuous flow from the mass to the main pulmonary artery. Because the pulmonary artery vessel wall was clearly defined, the mass was unlikely to originate from the pulmonary artery per se. Differential diagnosis included coronary artery aneurysm or arteriovenous malformation (online-only Data Supplement Movies I and II). Left