Diagnosis of Ostium Primum Defect at Multidetector CT in an Adult

Ostium primum, a type of atrial septal defect, occurs at the base of the interatrial septum and is the result of failure of fusion of the septum primum with the endocardial cushions. We describe a case of unrepaired ostium primum atrial septal defect in an adult that was diagnosed with multidetector computed tomography scan.