title: Magnetic resonance imaging-guided renal artery stent placement in a Swine model: comparison of two tracking techniques.
abstract: BACKGROUND
  Magnetic resonance (MR)-guided interventions have evolved from a pure research application to a preclinical method over the last decade. Among the device-tracking techniques, susceptibility artifact-based tracking relies on the contrast between the surrounding blood and the device, and radiofrequency coil-based tracking relies on the local gradient field amplification in a resonating circuit attached to the interventional device.
  
  
  OBJECTIVE
  To evaluate the feasibility and precision of susceptibility artifact-based and microcoil-based MR guidance methods for renal artery stent placement in a swine model.
  
  
  METHODS
  MR imaging-guided renal artery stent placements were performed in six fully anesthetized pigs using a 1.5T short-bore MR scanner. Susceptibility artifact-based tracking with manual scan-plane adjustments and microcoil tracking with automatic scan-plane adjustments were used for renal artery stent placements in three pigs in each group. With both methods, near real-time steady-state free-precession (SSFP) imaging was used. Differences between the two tracking approaches on stenting time, total procedure time, and stent position were measured.
  
  
  RESULTS
  The microcoil-based approach yielded a shorter mean procedure time (17 vs. 23 min). There was no relevant difference for the mean stenting time (12 vs. 13 min). The mean stent deviation from the aortic wall with the susceptibility approach was larger than with the microcoil approach (10 vs. 4.0 mm).
  
  
  CONCLUSIONS
  For MRI-guided renal artery stent placement, the microcoil-based technique had a shorter procedure time and a higher stent placement precision than the susceptibility artifact-based approach.
authors.affiliation: Radiology, Charité - Campus Benjamin Franklin, Berlin, Germany. bernd.frericks@charite.de
authors.forename: B B
authors.initials: BB
authors.lastname: Frericks
authors.forename: D R
authors.initials: DR
authors.lastname: Elgort
authors.forename: C
authors.initials: C
authors.lastname: Hillenbrand
authors.forename: J L
authors.initials: JL
authors.lastname: Duerk
authors.forename: J S
authors.initials: JS
authors.lastname: Lewin
authors.forename: F K
authors.initials: FK
authors.lastname: Wacker
mesh_terms: D000818:Animals; D016477:Artifacts; D003287:Contrast Media; D007472:Iohexol; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D012077:Renal Artery; D012984:Software; D015607:Stents; D013552:Swine
chemical_list: D003287:Contrast Media; D007472:Iohexol