@article{oai:kanazawa-u.repo.nii.ac.jp:00016517,
 author = {Koshida, Kichiro and Mizushima, Takashi and Yamamoto, Tomoyuki},
 journal = {金沢大学医学部保健学科紀要 = Memoirs of School of Health Sciences Faculty of Medicine Kanazawa University},
 month = {Dec},
 note = {In order to evaluate the x-ray quality in each material, we obtained the values from one to five half-value layer with aluminum, bakelite, polymethyl methacrylate resin and BR-12 phantom, and investigated the change of x-ray quality (from first to fifth half-value layer) according to the attenuation in their materials. The un-homogeneity factor to first half-value layer in BR-12 phantom was slightly low than that in aluminum, and especially was not as high as that in aluminum for the ratio of fifth half-value layer to first half-value layer. X-ray quality passed through the breast may be higher than that of the breast surface because of the transmission in the breast tissue. So the subject contrast would be decreasing. The thickness of the breast under compression in the clinical practice correspond to about four or five half-value layer. Therefore the x-ray quality must be evaluated by BR-12 phantom, being composed nearly with the breast.},
 pages = {43--48},
 title = {Study of X-ray Quality in Absorption Materials for Mammography},
 volume = {20},
 year = {1996}
}