title: MR imaging-guided percutaneous cryotherapy of liver tumors: initial experience.
abstract: OBJECTIVE
  To describe the cryoablation of liver tumors by using a percutaneous approach and intraprocedural magnetic resonance (MR) imaging monitoring and to assess the feasibility and safety of the procedure.
  
  
  METHODS
  Fifteen hepatic tumors (mean diameter, 2.9 cm) in 12 patients were treated (18 total cryoablations). Fourteen were metastases and one was a hemangioma; all were proved at biopsy. By using a 0.5-T open MR imaging system, cryoneedles were placed and lesions ablated by using real-time monitoring. Clinical signs and symptoms were assessed and laboratory tests performed. Intraprocedural depictions of iceballs were compared with contrast material-enhanced MR imaging-based estimates of cryonecrosis that were obtained 24 hours after cryoablation.
  
  
  RESULTS
  MR imaging-guided percutaneous cryotherapy resulted in no serious complications and no clinically important changes in serum liver enzymes or creatinine or myoglobin levels. Intraprocedural MR imaging demonstrated iceballs as sharply marginated regions of signal loss that expanded and engulfed tumors. The maximal iceball size was 4.9 x 2.2 x 2.2 cm with the use of one cryoneedle and 6.0 x 5.6 x 4.9 cm with three cryoneedles. Intraprocedural iceball depictions correlated well with postprocedural cryonecrosis estimates.
  
  
  CONCLUSIONS
  MR imaging-guided percutaneous cryotherapy of liver tumors is feasible and safe. MR imaging can be used to estimate cryotherapy effects and guide therapy intraprocedurally.
authors: Departments of Radiology, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115, USA.
authors: S G
authors: SG
authors: Silverman
authors: K
authors: K
authors: Tuncali
authors: D F
authors: DF
authors: Adams
authors: E
authors: E
authors: vanSonnenberg
authors: K H
authors: KH
authors: Zou
authors: D F
authors: DF
authors: Kacher
authors: P R
authors: PR
authors: Morrison
authors: F A
authors: FA
authors: Jolesz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017679:Cryotherapy / Q000009:adverse effects / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D015642:Radiology, Interventional