title: [Radiation dose evaluation in a photon-counting digital mammography unit].
abstract: The purpose of our study was to evaluate radiation dose and beam quality in photon-counting digital mammography (PCDM) and compare them with those in a full-field digital mammography (FFDM) unit. Dose variation in the X-ray tube axis direction, aluminum half-value layer, average glandular and skin doses, and contrast-to-noise ratio (CNR) were evaluated for the PCDM and FFDM units. In PCDM, the dose variation in the X-ray tube axis direction was greater than that in FFDM. At a tube voltage of 28 kV, the first half-value layers were 0.407 mmAl for PCDM, 0.357 mmAl for FFDM with a molybdenum target and molybdenum filter (Mo/Mo), and 0.579 mmAl for FFDM with a tungsten target and rhodium filter (W/Rh). The average glandular doses with 45-mm-equivalent breast thickness were 0.723 mGy for the PCDM, 1.55 mGy for the FFDM with Mo/Mo in low-dose mode, and 0.835 mGy for the FFDM with W/Rh in low-dose mode. In PCDM, the skin dose was equivalent to or lower than that in FFDM. The CNR was 2.65±0.04, 2.35±0.04, and 2.52±0.03 for the PCDM, FFDM with Mo/Mo, and that with W/Rh, respectively. The CNR for PCDM was significantly higher than that for FFDM (p<0.001). It is therefore possible to reduce the radiation dose to the patient by using a PCDM unit while maintaining a significantly higher CNR than with the FFDM unit.
authors.affiliation: Department of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa University.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Matsubara
authors.forename: China
authors.initials: C
authors.lastname: Matsumoto
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mochiya
authors.forename: Kanako
authors.initials: K
authors.lastname: Toda
authors.forename: Kimiya
authors.initials: K
authors.lastname: Noto
authors.forename: Kichiro
authors.initials: K
authors.lastname: Koshida
mesh_terms: D008327:Mammography / Q000295:instrumentation*; D019047:Phantoms, Imaging; D017785:Photons; D011786:Quality Control; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation*