title: Substantial dose reduction in modern multi-slice spiral computed tomography (MSCT)-guided craniofacial and skull base surgery.
abstract: OBJECTIVE
  Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs).
  
  
  METHODS
  An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120  kV/100  mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100  kV/35ref. mAs, (LD-II) 80  kV/40 - 41ref. mAs, and (LD-III) 80  kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05).
  
  
  RESULTS
  CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1.62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt für Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols.
  
  
  CONCLUSIONS
  Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery.
authors.affiliation: Department of Radiology, Innsbruck Medical University, Austria. Gerlig.Widmann@i-med.ac.at
authors.forename: G
authors.initials: G
authors.lastname: Widmann
authors.forename: M
authors.initials: M
authors.lastname: Fasser
authors.forename: P
authors.initials: P
authors.lastname: Schullian
authors.forename: A
authors.initials: A
authors.lastname: Zangerl
authors.forename: W
authors.initials: W
authors.lastname: Puelacher
authors.forename: F
authors.initials: F
authors.lastname: Kral
authors.forename: H
authors.initials: H
authors.lastname: Riechelmann
authors.forename: W
authors.initials: W
authors.lastname: Jaschke
authors.forename: R
authors.initials: R
authors.lastname: Bale
mesh_terms: D005624:Frontal Bone / Q000601:surgery*; D006801:Humans; D061330:Multidetector Computed Tomography / Q000379:methods*; D038361:Neuronavigation / Q000379:methods*; D056888:Patient Positioning; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control; D011856:Radiographic Image Enhancement / Q000379:methods; D012680:Sensitivity and Specificity; D019291:Skull Base / Q000601:surgery*; D013701:Temporal Bone / Q000601:surgery*