Isolated Unroofed Coronary Sinus on Three- Dimensional Computed Tomographic Imaging

A4-year-old girl was referred to our facility with a diagnosis of sinus venosus atrial septal defect. Although the transthoracic echocardiogram showed a moderate left-to-right shunt at the posteroinferior portion of the atrial septum, she had initially been referred with a diagnosis of sinus venosus defect. Repeated echocardiographic evaluations, however, implicated a defective roof of the coronary sinus. Three-dimensional computed tomography (SOMATOM Definition, Siemens Medical Systems, Forchheim, Germany) then defined a