title: Liver tumor laser ablation - increase in the subacute ablation lesion volume detected with post procedural MRI.
abstract: BACKGROUND
  The use of image-guided thermoablative methods in liver tumor treatment has expanded rapidly due to encouraging results and advanced imaging. However, little is known about the treatment-induced tissue response and effects on imaging findings during the subacute post procedural period.
  
  
  OBJECTIVE
  To study the development of subacute ablation zone volume with magnetic resonance imaging (MRI) after laser-mediated liver tumor thermal therapy.
  
  
  METHODS
  In all, 16 laser ablations were performed on 16 liver tumors resulting in 16 ablation zones in 11 consecutive patients. A low-field 0.23 T C-arm MRI scanner was used for imaging and procedural guidance. Repeated dynamic contrast-enhanced T1, contrast-enhanced T1 FSE, and T2 FSE studies of liver were performed at 0 and 72 h after the procedure. Ablation zone volumes were registered from the acquired image data.
  
  
  RESULTS
  MRI scans showed a significant increase of ablation volume in all imaging sequences obtained at 72 h after the initial therapy.
  
  
  CONCLUSIONS
  After laser ablation, there is a progressive perfusion decrease in the ablation site leading to an increase in the ablation volume. Post procedural baseline MRI at 72 h from the treatment provides more precise information about the ablation result than can be obtained with immediate post procedural MRI.
authors.affiliation: Department of Radiology, Oulu University Hospital, Oulu, Finland. roberto.blanco@oulu.fi
authors.forename: Roberto Blanco
authors.initials: RB
authors.lastname: Sequeiros
authors.forename: Juho
authors.initials: J
authors.lastname: Kariniemi
authors.forename: Risto
authors.initials: R
authors.lastname: Ojala
authors.forename: Li
authors.initials: L
authors.lastname: Chengli
authors.forename: Marianne
authors.initials: M
authors.lastname: Haapea
authors.forename: Andreas Blanco
authors.initials: AB
authors.lastname: Sequeiros
authors.forename: Osmo
authors.initials: O
authors.lastname: Tervonen
mesh_terms: D003287:Contrast Media; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D053685:Laser Therapy / Q000379:methods*; D008113:Liver Neoplasms / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012984:Software
chemical_list: D003287:Contrast Media