title: Magnetic Resonance-Monitored Coaxial Electrochemical Ablation--Preliminary Evaluation of Technical Feasibility.
abstract: OBJECTIVE
  To evaluate the technical feasibility of a coaxial electrode configuration to rapidly create a mechanically defined electrochemical ablation zone monitored by magnetic resonance (MR) imaging in real time.
  
  
  METHODS
  A direct current generator supplied the nitinol cathode cage and central platinum anode for coaxial electrochemical ablation. Safety and efficacy were evaluated by measuring local pH, temperature, and current scatter in saline solutions. Ablation zone diameters of 3-6 cm (n = 72) were created on ex vivo bovine liver and verified by gross pathology. Feasibility of MR monitoring was evaluated using 8 swine livers to create ablations of 3 cm (n = 12), 4 cm (n = 4), and 5 cm (n = 4) verified by histology.
  
  
  RESULTS
  Local pH was 3.2 at the anode and 13.8 at the cathode. Current scatter was negligible. Ablation progress increased relative to local ion concentration, and MR signal changes corresponded to histologic findings. In the ex vivo model, the times to achieve complete ablation were 15 minutes, 20 minutes, 35 minutes, and 40 minutes for diameters of 3 cm, 4 cm, 5 cm, and 6 cm, respectively. Ablation times for the in situ model were 15 minutes, 35 minutes, and 50 minutes for 3 cm, 4 cm, and 5 cm, respectively.
  
  
  CONCLUSIONS
  The coaxial configuration mechanically defined the electrochemical ablation zone with times similar to comparably sized thermal ablations. MR compatibility allowed for real-time monitoring of ablation progress.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104. Electronic address: ge.benjamin@gmail.com.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Ge
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Charles N
authors.initials: CN
authors.lastname: Weber
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wildenberg
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Nadolski
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Terence P
authors.initials: TP
authors.lastname: Gade
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Hunt
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Soulen
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Penn Image Guided Interventions Laboratory, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104; Department of Radiology, Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
authors.forename: Maxim
authors.initials: M
authors.lastname: Itkin
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000818:Animals; D018274:Electroporation / Q000379:methods*; D005240:Feasibility Studies; D008099:Liver / Q000473:pathology* / Q000601:surgery*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D010865:Pilot Projects; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013552:Swine