Magnetic Resonance Imaging of the Cardiac Venous System and Magnetic Resonance-Guided Intubation of the Coronary Sinus in Swine A Feasibility Study

Objectives: To visualize the coronary sinus using magnetic resonance (MR), and to demonstrate the feasibility of MR-guided intubation of the cardiac venous system (CVS) in swine. Materials and Methods: A total of 6 pigs were investigated. All experiments were performed using an interventional 1.5-Tesla MRI system. The CVS was visualized using an inversion-recovery navigator-gated whole-heart steady-state free-precession sequence after administration of gadobenate dimeglumine contrast agent. 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-braided Cobra-catheter. MR-guided interventions were monitored using a steady-state free-precession real-time imaging sequence. Time needed was measured for MR-guided intubation of the CVS and compared with the time needed for fluoroscopy guided intubation of the CVS. Results: Visualization and intubation of the coronary sinus and its site branches was feasible in all cases. Time spent for MR-guided intubation of the CVS was comparable to time spent for fluoroscopy-guided intubation (8.2 +/- 2 minutes vs. 8.3 +/- 1.3 minutes; P = 0.85). Conclusions: MR-visualization and MR-guided intubation of the coronary sinus and its side branches is feasible. The feasibility of MR-guided intubation of the CVS might have relevance for procedures like cardiac resynchronization therapy and percutaneous transcatheter mitral annuloplasty, requiring improved 3-dimensional knowledge about cardiac vein anatomy in the near future.