title: Accuracy of combined PET/CT in image-guided interventions of liver lesions: an ex-vivo study.
abstract: OBJECTIVE
  Positioning of interventional devices in liver lesions is a challenging task if only CT is available. We investigated the potential benefit of combined PET/CT images for localization of interventional devices in interventional liver studies.
  
  
  METHODS
  Thirty lesions each of hyperdense, isodense and hypodense attenuation compared to normal liver parenchyma were injected into 15 ex-vivo pig livers. All lesions were composed of the same amounts of gelatine containing 0.5 MBq of (18)F-FDG. Following lesion insertion, an interventional needle was placed in each lesion under CT-guidance solely. After that, a PET/CT study was performed. The localization of the needle within the lesion was assessed for CT alone and PET/CT and the root mean square (RMS) was calculated. Results were compared with macroscopic measurements after lesion dissection serving as the standard of reference.
  
  
  RESULTS
  In hypo- and isodense lesions PET/CT proved more accurate in defining the position of the interventional device when compared with CT alone. The mean RMS for CT and PET/CT differed significantly in isodense and hypodense lesions. No significant difference was found for hyperdense lesions.
  
  
  CONCLUSIONS
  Combined FDG-PET/CT imaging provides more accurate information than CT alone concerning the needle position in FDG-PET positive liver lesions. Therefore combined PET/CT might be potentially beneficial not only for localization of an interventional device, but may also be beneficial for guidance in interventional liver procedures.
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Essen, Hufelandstrasse 55, 45122 Essen, Germany. patrick.veit@uni-essen.de
authors: Patrick
authors: P
authors: Veit
authors: Christiane
authors: C
authors: Kuehle
authors: Thomas
authors: T
authors: Beyer
authors: Hilmar
authors: H
authors: Kuehl
authors: Andreas
authors: A
authors: Bockisch
authors: Gerald
authors: G
authors: Antoch