title: Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging.
abstract: OBJECTIVE
  To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT.
  
  
  METHODS
  Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm(2) removes the necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems.
  
  
  RESULTS
  The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63%/39% lower for the third generation examination as compared to the first and second generation DSCT.
  
  
  CONCLUSIONS
  Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs.
  
  
  CONCLUSIONS
  • Omitting the z-axis-filter allows a reduction in radiation dose of 50% • A smaller focal spot of 0.2 mm (2) significantly improves spatial resolution • Ultra-high-resolution temporal-bone-CT helps to gain diagnostic information of the middle/inner ear.
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany, Mathias.Meyer@medma.uni-heidelberg.de.
authors.forename: Mathias
authors.initials: M
authors.lastname: Meyer
authors.forename: Holger
authors.initials: H
authors.lastname: Haubenreisser
authors.forename: Rainer
authors.initials: R
authors.lastname: Raupach
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Florian
authors.initials: F
authors.lastname: Lietzmann
authors.forename: Christianne
authors.initials: C
authors.lastname: Leidecker
authors.forename: Thomas
authors.initials: T
authors.lastname: Allmendinger
authors.forename: Thomas
authors.initials: T
authors.lastname: Flohr
authors.forename: Lothar R
authors.initials: LR
authors.lastname: Schad
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: Thomas
authors.initials: T
authors.lastname: Henzler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D011829:Radiation Dosage; D015203:Reproducibility of Results; D013701:Temporal Bone / Q000000981:diagnostic imaging*