title: Comparison of the Detection Rate of Simulated Microcalcifications in Full-Field Digital Mammography, Digital Breast Tomosynthesis, and Synthetically Reconstructed 2-Dimensional Images Performed With 2 Different Digital X-ray Mammography Systems.
abstract: The aim of this study was to compare the microcalcification detectability in an anthropomorphic phantom model regarding number, size, and shape in full-field digital mammography (FFDM), synthetically reconstructed 2-dimensional (Synthetic-2D) images, and digital breast tomosynthesis (DBT) performed with 2 different x-ray mammography systems.
  
  
  
  Simulated microcalcifications of different numbers (0 to >39), sizes (diameter, 100-800 μm), and shapes (round vs heterogeneous) were scattered by random distribution on 50 film phantoms each divided in 4 quadrants. The FFDM and DBT x-rays were taken from each of these 50 films with both x-ray mammography systems (SenoClaire; GE Healthcare, Selenia Dimensions, Hologic) using an anthropomorphic scattering body and automatic exposure control. The resulting exposure factors were similar to a clinical setting. The synthetically reconstructed 2D images were generated automatically on both systems. All FFDM, Synthetic-2D, and DBT images were interpreted in randomized order and independently of each other by 6 radiologists using a structured questionnaire.
  
  
  
  The number categories of simulated microcalcifications were correctly evaluated in 55.3% of instances (quadrant by reader) in FFDM, 50.9% in the Synthetic-2D views, and 59.5% in DBT, summarized for 200 quadrants per reader for each Device A and B, respectively. Full-field digital mammography was superior to Synthetic-2D (mean difference, 4%; 95% confidence interval [CI], 2%-7%; P < 0.001), and DBT was superior to both FFDM (mean difference, 4%; 95% CI, 2%-7%; P = 0.002) and Synthetic-2D (mean difference, 9%; 95% CI, 6%-11%; P < 0.001). This trend was consistent in all subgroup analyses. The number of the smallest microcalcifications (100-399 μm) was correctly evaluated in 25.2% of the FFDM, in 14.2% for Synthetic-2D, and in 28.3% of the DBT images. Underestimations of the number of simulated microcalcifications were more common than overestimations. Regarding the size categories of simulated microcalcifications, the rates of correct assessments were in 45.4% of instances in FFDM, 39.9% in the Synthetic-2D views, and 43.6% in DBT, summarized for 200 quadrants per reader and both imaging devices.
  
  
  
  In the presented in vitro environment using an anthropomorphic phantom model, standard full-field digital x-ray mammography was superior to synthetically reconstructed 2-dimensional images in the detection of simulated microcalcifications. In view of these results, it is questionable whether Synthetic-2D images can replace FFDM in clinical examinations at the present time. Further investigations are needed to assess the clinical impact of the in vitro results.
authors.affiliation: From the *Prüfstelle für Strahlenschutz GmbH, Wennigsen; †Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen; ‡Institute of Medical Statistics, Informatics and Epidemiology, University of Cologne, Cologne; §Radiological Institute Düsseldorf, Düsseldorf; ∥Clinical Radiology, University Witten/Herdecke, Witten; and ¶Department of Diagnostical and Interventional Radiology, University Hospital of Cologne, Cologne, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Peters
authors.forename: Martin
authors.initials: M
authors.lastname: Hellmich
authors.forename: Alexander
authors.initials: A
authors.lastname: Stork
authors.forename: Jörn
authors.initials: J
authors.lastname: Kemper
authors.forename: Olga
authors.initials: O
authors.lastname: Grinstein
authors.forename: Michael
authors.initials: M
authors.lastname: Püsken
authors.forename: Leandra
authors.initials: L
authors.lastname: Stahlhut
authors.forename: Sonja
authors.initials: S
authors.lastname: Kinner
authors.forename: David
authors.initials: D
authors.lastname: Maintz
authors.forename: Kathrin Barbara
authors.initials: KB
authors.lastname: Krug
mesh_terms: D001941:Breast Diseases / Q000000981:diagnostic imaging*; D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008327:Mammography / Q000295:instrumentation* / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results