Intravascular ultrasound shows the detailed appearance of an unraveled coil identified on echocardiography.

A 4-year-old boy who underwent coil embolization 17 months earlier was admitted for catheter assessment after the Fontan operation. Echocardiography showed a bright linear shadow in the abdominal aorta. Enhanced computed tomography of the chest showed that the coil had unraveled from the collateral arteries to the celiac branch artery. Subsequent catheter examination was performed safely. Intravascular ultrasound (IVUS) showed the unraveled coil floating in the aorta without a thrombus. This is a rare case to assess the appearance of unraveled coil with echocardiography and IVUS.