title: Ultrasound imaging in neurosurgery: approaches to minimize surgically induced image artefacts for improved resection control.
abstract: BACKGROUND
  Intraoperative ultrasound imaging is used in brain tumor surgery to identify tumor remnants. The ultrasound images may in some cases be more difficult to interpret in the later stages of the operation than in the beginning of the operation. The aim of this paper is to explain the causes of surgically induced ultrasound artefacts and how they can be recognized and reduced.
  
  
  METHODS
  The theoretical reasons for artefacts are addressed and the impact of surgery is discussed. Different setups for ultrasound acquisition and different acoustic coupling fluids to fill up the resection cavity are evaluated with respect to improved image quality.
  
  
  RESULTS
  The enhancement artefact caused by differences in attenuation of the resection cavity fluid and the surrounding brain is the most dominating surgically induced ultrasound artefact. The influence of the artefact may be reduced by inserting ultrasound probes with small footprint into the resection cavity for a close-up view of the areas with suspected tumor remnants. A novel acoustic coupling fluid developed for use during ultrasound imaging in brain tumor surgery has the potential to reduce surgically induced ultrasound artefacts to a minimum.
  
  
  CONCLUSIONS
  Surgeons should be aware of artefacts in ultrasound images that may occur during brain tumor surgery. Techniques to identify and reduce image artefacts are useful and should be known to users of ultrasound in brain tumor surgery.
authors: Department of Medical Technology, SINTEF, PO Box 4760, Sluppen, 7465, Trondheim, Norway. tormod.selbekk@sintef.no
authors: Tormod
authors: T
authors: Selbekk
authors: Asgeir Store
authors: AS
authors: Jakola
authors: Ole
authors: O
authors: Solheim
authors: Tonni Franke
authors: TF
authors: Johansen
authors: Frank
authors: F
authors: Lindseth
authors: Ingerid
authors: I
authors: Reinertsen
authors: Geirmund
authors: G
authors: Unsgård
mesh_terms: D001921:Brain / Q000473:pathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019635:Neurosurgical Procedures / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome; D014463:Ultrasonography