title: Determination of Tube Output (kVp) and Exposure Mode for Breast Phantom of Various Thicknesses/Glandularity for Digital Mammography.
abstract: BACKGROUND
  Optimisation of average glandular dose (AGD) for two-dimensional (2D) mammography is important, as imaging using ionizing radiation has the probability to induce cancer resulting from stochastic effects. This study aims to observe the effects of kVp, anode/filter material, and exposure mode on the dose and image quality of 2D mammography.
  
  
  METHODS
  This experimental study was conducted using full-field digital mammography. The entrance surface air kerma was determined using thermoluminescent dosimeter (TLD) 100H and ionization chamber (IC) on three types of Computerized Imaging Reference System (CIRS) phantom with 50/50, 30/70, and 20/80 breast glandularity, respectively, in the auto-time mode and auto-filter mode. The Euref protocol was used to calculate the AGD while the image quality was evaluated using contrast-to-noise ratio (CNR), figure of merit (FOM), and image quality figure (IQF).
  
  
  RESULTS
  It is shown that AGD values in the auto-time mode did not decrease significantly with the increasing tube voltage of the silver filter (r = -0.187, P > 0.05) and rhodium filter (r = -0.131, P > 0.05) for all the phantoms. The general linear model showed that AGD for all phantoms had a significant effect between different exposure factors [F (6,12.3) = 4.48 and mode of exposure F (1,86) = 4.17, P < 0.05, respectively] but there is no significant difference between the different anode/filter combination [F (1,4) = 0.571].
  
  
  CONCLUSIONS
  In summary, the 28, 29, and 31 kVp are the optimum kVp for 50%, 30%, and 20% breast glandularity, respectively. Besides the auto-filter mode is suitable for 50%, 30%, and 20% breast glandularity because it is automatic, faster, and may avoid error done by the operator.
authors.affiliation: Diagnostic Imaging and Radiotherapy Programme, Faculty of Health Sciences, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
authors.forename: Kamal
authors.initials: K
authors.lastname: Izdihar
authors.affiliation: Diagnostic Imaging and Radiotherapy Programme, Faculty of Health Sciences, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
authors.forename: Kumari Chelliah
authors.initials: KC
authors.lastname: Kanaga
authors.affiliation: Diagnostic Imaging Department, Hospital Tengku Ampuan Rahimah, Jalan Langat, 41200 Klang, Selangor, Malaysia.
authors.forename: Vijayalakshimi
authors.initials: V
authors.lastname: Krishnapillai
authors.affiliation: The National Cancer Society of Malaysia, Women's Cancer Detection and Breast Clinic, 66 Jalan Raja Muda Abd Aziz, 50300 Kuala Lumpur, Malaysia.
authors.forename: Tamanang
authors.initials: T
authors.lastname: Sulaiman
keywords: CDMAM; digital mammography; radiation dose