MR-guided coil embolisation of renal arteries in an animal model

Purpose: To test the feasibility of MR-guided coil embolization with passive visualization in an animal model. Materials and Methods: All experiments were performed on a 1.5 T interventional MR-scanner (Gyroscan ACS-NT, Philips, Netherlands). A gradient echo sequence was combined with radial k-space acquisition and sliding window reconstruction technique to calculate the raw data with a specially designed back projector, yielding a frame rate of 20 images per second. The images were directly displayed on LCD-screens next to the MR scanner. A multipurpose catheter with dysprosium markers was placed into the renal arteries of two pigs under MR guidance, and a nitinol coil and platinum coil each were deployed. The position of the coils was verified with magnetic resonance angiography and conventional angiography. Results: MR-guided catheterization of renal arteries with subsequent coil embolization was successfully carried out but the configuration of the coils could not be visualized on the MR images. Conclusion: MR-guided coil embolization of renal arteries is feasible. Exact guidance of coil deployment is not attainable with passive visualization.