Closed chest transthoracic perventricular ventricular septal defect closure under real-time MRI. Panel A shows muscular ventricular septal defect (thick, black arrow) highlighted by steady state free precession (SSFP) imaging. In pre-determined optimal imaging planes, "active" needle (red with needle tip appearing as bright red spot) puncture of the right thoraz and subsequently the right ventricular free wall is shown in panel B. Panel C shows ventricular septal defect closure device (thick, white arrow) with left ventricular disk deployed. Panel D shows succesful device implantation (black arrowhead).