title: Angiographic C-arm CT- versus MDCT-guided stereotactic punctures of liver lesions: nonrigid phantom study.
abstract: OBJECTIVE
  Angiographic C-arm CT may allow performing percutaneous stereotactic tumor ablations in the interventional radiology suite. Our purpose was to evaluate the accuracy of using C-arm CT for single and multimodality image fusions and to compare the targeting accuracy of liver lesions with the reference standard of MDCT.
  
  
  METHODS
  C-arm CT and MDCT scans were obtained of a nonrigid rapid prototyping liver phantom containing five 1-mm targets that were placed under skin-simulating deformable plastic foam. Target registration errors of image fusion were evaluated for single-modality and multimodality image fusions. A navigation system and stereotactic aiming device were used to evaluate target positioning errors on postinterventional scans with the needles in place fused with the C-arm CT or MDCT planning images.
  
  
  RESULTS
  Target registration error of the image fusion showed no significant difference (p > 0.05) between both modalities. In five series with a total of 25 punctures for each modality, the lateral target positioning error (i.e., the lateral distance between the needle tip and the planned trajectory) was similar for C-arm CT (mean [± SD], 1.6 ± 0.6 mm) and MDCT (1.82 ± .97 mm) (p = 0.33).
  
  
  CONCLUSIONS
  In a nonrigid liver phantom, angiographic C-arm CT may provide similar image fusion accuracy for comparison of intra- and postprocedure control images with the planning images and enables stereotactic targeting accuracy similar to that of MDCT.
authors.affiliation: 1 Section of Microinvasive Therapy, Department of Radiology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.
authors.forename: Gerlig
authors.initials: G
authors.lastname: Widmann
authors.forename: Daphné
authors.initials: D
authors.lastname: Wallach
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Toporek
authors.forename: Peter
authors.initials: P
authors.lastname: Schullian
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Reto
authors.initials: R
authors.lastname: Bale
mesh_terms: D000792:Angiography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008099:Liver / Q000098:blood supply*; D008113:Liver Neoplasms / Q000628:therapy; D019047:Phantoms, Imaging; D011677:Punctures; D015641:Radiography, Interventional; D013238:Stereotaxic Techniques; D014057:Tomography, X-Ray Computed / Q000379:methods*