Endovascular interventional MRI at 3T

Purpose: To assess the feasibility of MR-guided endovascular interventions at 3 T, using catheters marked with iron particles.

Materials and Methods: Different interventional procedures were performed in 12 pigs as follows: In 4 animals surgically induced stenosis of the femoral arteries were dilated using a balloon catheter filled with Gd-DTPA solution. In 4 pigs nitinol stents were placed in the iliac arteries. In the remaining 4 animals, segmental renal arteries were embolized with 0.5ml butylcyanoacrylate (Histoacryl, B. Braun, Germany), mixed with lipoidol and iron particles. A non-metallic guide wire and non-braided catheters doted with iron-particles were used for the interventions. Catheter manipulations were monitored with a real-time true-FISP sequence (TR/TE 2.5ms/1.25ms, flip angle 40°, matrix 128×128; FOV 320mm; slice thickness 8mm).

Results: During the different interventions the guide wire and catheters were clearly visible on the real time images and could be followed during all manipulations by on-line changing the slice position and imaging plane. In the animals with stenosis in the iliac arteries, the stenosis could successfully be passed with the guide wire and dilated. The stents were deployed in the iliac arteries at the target region. The renal arteries could be probed with a cobra catheter, segmental arteries selectively probed in the coaxial technique and embolized. Complications were not encountered during the procedures or at autopsy.

Conclusion: Endovascular intervention are feasible at 3 T using real-time imaging and MR-compatible, iron marked catheters and guide wires.