Isolated anomalous origin of the right coronary artery from the pulmonary artery in an asymptomatic 12-year-old girl: role of MRI in depicting the anatomy, detecting the ischemic burden, and quantifying the amount of left-to-right shunt.

Asymptomatic 12-year-old girl with a heart murmur underwent echocardiogram and suspicious continuous flow was detected in her interventricular septum. She underwent cardiac magnetic resonance (CMR) for further investigation. The CMR images demonstrated anomalous origin of the right coronary artery from the pulmonary artery. Adenosine stress perfusion scan showed an inducible perfusion defect in the right coronary artery and left circumflex artery territories. Flow quantification showed a left-to-right shunt with pulmonary to systemic blood flow ratio (Qp/Qs) of 1.25.