title: Irreversible electroporation ablation of malignant hepatic tumors: subacute and follow-up CT appearance of ablation zones.
abstract: OBJECTIVE
  To describe findings on contrast-enhanced computed tomography (CT) images of malignant hepatic tumors 24-72 hours after percutaneous ablation by irreversible electroporation (IRE) and at midterm follow-up.
  
  
  METHODS
  Retrospective analysis of 52 malignant liver tumors-30 primary hepatic tumors and 22 hepatic metastases-in 34 patients (28 men and 6 women, mean age 64 y) treated by IRE ablation was performed. Ablation zones were evaluated by two examiners in a consensus reading by means of a dual-phase CT scan (consisting of a hepatic arterial and portal venous phase) performed 24-72 hours after IRE ablation and at follow-up.
  
  
  RESULTS
  During the portal venous phase, ablation zones either were homogeneously hypoattenuating (n = 36) or contained heterogeneously isoattenuating or hyperattenuating (n = 16) foci, or both, in a hypoattenuating area. Of 52 lesions, 38 included gas pockets. Peripheral contrast enhancement of the ablation defect was evident in 23 tumors during the arterial phase and in 36 tumors during the portal venous phase. Four tumors showed intralesional abscesses after the intervention. At follow-up (mean, 4.7 mo), the mean volume of the ablation defects was reduced to 29% of their initial value.
  
  
  CONCLUSIONS
  Because normal findings on contrast-enhanced CT images after IRE ablation may be very similar to the typical characteristics of potential complications following ablation, such as liver abscesses, CT scans must be carefully analyzed to distinguish normal results after intervention from complications requiring further treatment.
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.. Electronic address: marco.dollinger@ukr.de.
authors.forename: Marco
authors.initials: M
authors.lastname: Dollinger
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: Ernst-Michael
authors.initials: EM
authors.lastname: Jung
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Beyer
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Niessen
authors.affiliation: Institute of Diagnostic and Interventional Radiology, Westküstenklinikum Heide, Heide, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Scheer
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Müller-Wille
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stroszczynski
authors.affiliation: Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93042 Regensburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Wiggermann
mesh_terms: D055011:Ablation Techniques / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D018274:Electroporation; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media