title: MR-guided percutaneous nephrostomy of the nondilated upper urinary tract in a porcine model.
abstract: OBJECTIVE
  The purpose of this study was to assess the safety and feasibility of MR-guided percutaneous nephrostomy of the nondilated contrast-enhanced upper urinary tract in a porcine model.
  
  
  METHODS
  Six MR-guided percutaneous nephrostomies of the nondilated upper urinary tract were performed in four domestic farm pigs (body weight range, 20-25 kg) using a 0.2-T system. Ten minutes after IV administration of 0.2 mmol/kg of gadodiamide and 0.4 mg/kg of furosemide, a fast T1-weighted sequence was used to guide insertion of an 18-gauge MR-compatible needle into a predetermined calix. After confirmation of needle position using a turbo spin-echo T1-weighted sequence, a 0.035-inch catheter coated with superparamagnetic iron oxide was inserted during MR monitoring. Insertion was followed by tract dilatation and insertion of a 4-French sheath. The final position of the sheath was confirmed by injection of diluted superparamagnetic iron oxide into the collecting system.
  
  
  RESULTS
  Needle insertion was successful for all six procedures, with no complications. Instrumentation time ranged from 4 to 13 min (mean, 6+/-4 min). Sheath placement was successful in five of six kidneys. Placement time ranged from 6 to 28 min (mean, 16+/-9 min).
  
  
  CONCLUSIONS
  MR-guided percutaneous nephrostomy of the nondilated contrast-enhanced upper urinary tract in a porcine model is feasible and safe.
authors.affiliation: Department of Radiology, University Hospitals of Cleveland/Case Western Reserve University, OH 44106, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Merkle
authors.forename: M
authors.initials: M
authors.lastname: Hashim
authors.forename: M
authors.initials: M
authors.lastname: Wendt
authors.forename: J S
authors.initials: JS
authors.lastname: Lewin
mesh_terms: D000818:Animals; D003287:Contrast Media; D003911:Dextrans; D005240:Feasibility Studies; D005260:Female; D052203:Ferrosoferric Oxide; D019786:Gadolinium DTPA; D007275:Injections, Intravenous; D007501:Iron; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D010087:Oxides; D013535:Suspensions; D013552:Swine
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D013535:Suspensions; C064925:gadodiamide; D007501:Iron; C065507:ferumoxides; D019786:Gadolinium DTPA; D052203:Ferrosoferric Oxide