title: Dose Reduction in Tomosynthesis of the Wrist.
abstract: OBJECTIVE
  The purpose of this study was to quantitatively and qualitatively determine the impact of radiation dose reduction on the image noise and quality of tomosynthesis studies of the wrist.
  
  
  METHODS
  Imaging of six cadaver wrists was performed with tomosynthesis in anteroposterior position at a tube voltage of 60 kV and tube current of 80 mA and subsequently at 60 or 50 kV with different tube currents of 80, 40, or 32 mA. Dose-area products (DAP) were obtained from the electronically logged protocol. Image noise was measured with an ROI. Two independent and blinded readers evaluated all images. Interreader agreement was measured with a Cohen kappa. Readers assessed overall quality and delineation of soft tissue, cortical bone, and trabecular bone on a 4-point Likert scale.
  
  
  RESULTS
  The highest DAP (3.892 ± 0.432 Gy · cm2) was recorded for images obtained with 60 kV and 80 mA; the lowest (0.857 ± 0.178 Gy · cm2) was recorded for images obtained with 50 kV and 32 mA. Noise was highest when a combination of 50 kV and 32 mA (389 ± 26.6) was used and lowest when a combination of 60 kV and 80 mA (218 ± 12.3) was used. The amount of noise on images acquired using 60 kV and 80 mA was statistically significantly different from the amount measured on all other images (p < 0.0001). Interreader agreement was excellent (κ = 0.93). Delineation of anatomy and overall quality were scored best on images obtained with 60 kV and 80 mA and worst on images obtained with 50 kV and 32 mA. The difference in delineation and quality on images obtained using 50 kV and 40 mA was not statistically significantly different compared with images obtained using 60 kV and 80 mA.
  
  
  CONCLUSIONS
  Significant dose reduction for tomosynthesis of the wrist is possible while image quality and delineation of anatomic structures remain preserved.
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Anton S
authors.initials: AS
authors.lastname: Becker
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Katharina
authors.initials: K
authors.lastname: Martini
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Kai
authors.initials: K
authors.lastname: Higashigaito
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Roman
authors.initials: R
authors.lastname: Guggenberger
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Gustav
authors.initials: G
authors.lastname: Andreisek
authors.affiliation: 1 Department of Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenfelder
mesh_terms: D000368:Aged; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014953:Wrist / Q000000981:diagnostic imaging*; D014955:Wrist Joint / Q000000981:diagnostic imaging*
keywords: radiography; radiometry; tomosynthesis; wrist joint; x-ray