Real time CMR guided pericardiocentesis using a “passive” needle. Real time CMR guides pericardiocentesis performed with commercially available, off-the-shelf needle (white arrow). Panels A and B show typical long-axis imaging planes selected by the operators. This animal has a small (50 ml) effusion. Note the “saturation band” of reduced T1 recovery (and reduced signal) where the two imaging planes intersect.