title: Clinical experience of photon counting breast tomosynthesis: comparison with traditional mammography.
abstract: BACKGROUND
  In two-dimensional mammography, a well-known problem is over- and underlying tissue which can either obstruct a lesion or create a false-positive result. Tomosynthesis, with an ability to layer the tissue in the image, has the potential to resolve these issues.
  
  
  OBJECTIVE
  To compare the diagnostic quality, sensitivity and specificity of a single tomosynthesis mammography image and a traditional two-view set of two-dimensional mammograms and to assess the comfort of the two techniques.
  
  
  METHODS
  One hundred and forty-four women, mainly chosen because of suspicious features on standard mammograms (76 malignant), had a single tomosynthesis image taken of one breast using a novel photon counting system. On average, the dose of the tomosynthesis images was 0.63 times that of the two-view images and the compression force during the procedure was halved. The resulting images were viewed by two radiologists and assessed both individually and comparing the two techniques.
  
  
  RESULTS
  In 56% of the cases the radiologists rated the diagnostic quality of the lesion details higher in the tomosynthesis images than in the conventional images (and in 91% equal or higher), which means there is a statistically significant preference for the tomosynthesis technique. This included the calcifications which were rated as having better quality in 41% of the cases. While sensitivity was slightly higher for traditional mammography the specificity was higher for tomosynthesis. However, neither of these two differences was large enough to be statistically significant.
  
  
  CONCLUSIONS
  The overall accuracy of the two techniques was virtually equal despite the radiologist's very limited experience with tomosynthesis images and vast experience with two-dimensional mammography. As the diagnostic quality of the lesion details in the tomosynthesis images was valued considerably higher this factor should improve with experience. The patients also favored the tomosynthesis examination, rating the comfort of the procedure as much higher than regular mammography which might affect screening attendance.
authors.affiliation: Department of Radiology, Karolinska University Hospital and Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm. gunilla.svane@ki.se
authors.forename: Gunilla
authors.initials: G
authors.lastname: Svane
authors.forename: Edward
authors.initials: E
authors.lastname: Azavedo
authors.forename: Karin
authors.initials: K
authors.lastname: Lindman
authors.forename: Mattias
authors.initials: M
authors.lastname: Urech
authors.forename: Jonas
authors.initials: J
authors.lastname: Nilsson
authors.forename: Niclas
authors.initials: N
authors.lastname: Weber
authors.forename: Lars
authors.initials: L
authors.lastname: Lindqvist
authors.forename: Christer
authors.initials: C
authors.lastname: Ullberg
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D017785:Photons; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity