title: Development of low-dose photon-counting contrast-enhanced tomosynthesis with spectral imaging.
abstract: OBJECTIVE
  To demonstrate the feasibility of low-dose photon-counting tomosynthesis in combination with a contrast agent (contrast material-enhanced tomographic mammography) for the differentiation of breast cancer.
  
  
  METHODS
  All studies were approved by the institutional review board, and all patients provided written informed consent. A phantom model with wells of iodinated contrast material (3 mg of iodine per milliliter) 1, 2, 5, 10, and 15 mm in diameter was assessed. Nine patients with malignant lesions and one with a high-risk lesion (atypical papilloma) were included (all women; mean age, 60.7 years). A multislit photon-counting tomosynthesis system was utilized (spectral imaging) to produce both low- and high-energy tomographic data (below and above the k edge of iodine, respectively) in a single scan, which allowed for dual-energy visualization of iodine. Images were obtained prior to contrast material administration and 120 and 480 seconds after contrast material administration. Four readers independently assessed the images along with conventional mammograms, ultrasonographic images, and magnetic resonance images. Glandular dose was estimated.
  
  
  RESULTS
  Contrast agent was visible in the phantom model with simulated spherical tumor diameters as small as 5 mm. The average glandular dose was measured as 0.42 mGy per complete spectral imaging tomosynthesis scan of one breast. Because there were three time points (prior to contrast medium administration and 120 and 480 seconds after contrast medium administration), this resulted in a total dose of 1.26 mGy for the whole procedure in the breast with the abnormality. Seven of 10 cases were categorized as Breast Imaging Reporting and Data System score of 4 or higher by all four readers when reviewing spectral images in combination with mammograms. One lesion near the chest wall was not captured on the spectral image because of a positioning problem.
  
  
  CONCLUSIONS
  The use of contrast-enhanced tomographic mammography has been demonstrated successfully in patients with promising diagnostic benefit. Further studies are necessary to fully assess diagnostic sensitivity and specificity.
authors.affiliation: Department of Radiology, Charité University of Medicine, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Florian F
authors.initials: FF
authors.lastname: Schmitzberger
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Fallenberg
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Lawaczeck
authors.forename: Magnus
authors.initials: M
authors.lastname: Hemmendorff
authors.forename: Elin
authors.initials: E
authors.lastname: Moa
authors.forename: Mats
authors.initials: M
authors.lastname: Danielsson
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bick
authors.forename: Susanne
authors.initials: S
authors.lastname: Diekmann
authors.forename: Alexander
authors.initials: A
authors.lastname: Pöllinger
authors.forename: Florian J
authors.initials: FJ
authors.lastname: Engelken
authors.forename: Felix
authors.initials: F
authors.lastname: Diekmann
mesh_terms: D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007472:Iohexol / Q000031:analogs & derivatives*; D008279:Magnetic Resonance Imaging; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D019047:Phantoms, Imaging; D017785:Photons; D011829:Radiation Dosage; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D019786:Gadolinium DTPA