Fig. 4

Depicts successful iCMR Fontan fenestration test occlusion (FFTO) followed by successful Fontan fenestration device closure (FFDC) in the x-ray fluoroscopy cath lab. a Under iCMR, the Fontan fenestration (FF) was crossed using an MR-conditional guidewire. An MR-conditional guidewire is seen across the Fontan fenestration and in the RA appendage. b The gadolinium-filled balloon was deflated to advance across the FF, inflated again in the right/pulmonary venous atrium and then pulled back to perform FFTO. Cath and CMR hemodynamics were repeated with FFTO. c If deemed appropriate, the subject was transferred to the x-ray fluoroscopy lab for FFDC. Solid White Arrow– MR-conditional guidewire;Dashed White Arrow– Gadolinium-filled balloon