Magnetic Resonance (MR) Imaging of the cardiac venous system and MR-guided intubation of the coronary sinus in swine: a feasibility-study

Methods 6 pigs were investigated. All experiments were performed using an interventional 1.5 Tesla MRI system. The CVS was visualized using an inversion-recovery navigatorgated whole-heart steady-state free precession sequence after administration of Gd-BOPTA contrast agent (130150 slices, voxel size 1.2 × 1.2 × 1.8 mm3, TR/TE 6.4/3.2, flip angle 85°. Parallel imaging was used with a SENSEfactor of 2. The coronary sinus was then intubated under MR-guidance with a passive MR-compatible guidewire modified by incorporation of iron oxide markers for improved visualization and a non-braded Cobra-catheter. MR-guided interventions were monitored using a steadystate free precession real-time imaging sequence. Parameters of the real-time imaging sequence were TR/TE = 2.5/ 1.25 ms, flip angle 45°, slice thickness 8 mm, matrix 128 × 128 reconstructed to 256 × 256 using zero-filling. Planning of the image planes, especially for the coronary sinus, were performed with the help of the wholeheart acquisition. Time needed was measured for MR-guided intubation of the CVS and compared to the time needed for fluoroscopy guided intubation of the CVS.