title: Mammographic density assessed on paired raw and processed digital images and on paired screen-film and digital images across three mammography systems.
abstract: Inter-women and intra-women comparisons of mammographic density (MD) are needed in research, clinical and screening applications; however, MD measurements are influenced by mammography modality (screen film/digital) and digital image format (raw/processed). We aimed to examine differences in MD assessed on these image types.
  
  
  
  We obtained 1294 pairs of images saved in both raw and processed formats from Hologic and General Electric (GE) direct digital systems and a Fuji computed radiography (CR) system, and 128 screen-film and processed CR-digital pairs from consecutive screening rounds. Four readers performed Cumulus-based MD measurements (n = 3441), with each image pair read by the same reader. Multi-level models of square-root percent MD were fitted, with a random intercept for woman, to estimate processed-raw MD differences.
  
  
  
  Breast area did not differ in processed images compared with that in raw images, but the percent MD was higher, due to a larger dense area (median 28.5 and 25.4 cm2respectively, mean √dense area difference 0.44 cm (95% CI: 0.36, 0.52)). This difference in √dense area was significant for direct digital systems (Hologic 0.50 cm (95% CI: 0.39, 0.61), GE 0.56 cm (95% CI: 0.42, 0.69)) but not for Fuji CR (0.06 cm (95% CI: -0.10, 0.23)). Additionally, within each system, reader-specific differences varied in magnitude and direction (p < 0.001). Conversion equations revealed differences converged to zero with increasing dense area. MD differences between screen-film and processed digital on the subsequent screening round were consistent with expected time-related MD declines.
  
  
  
  MD was slightly higher when measured on processed than on raw direct digital mammograms. Comparisons of MD on these image formats should ideally control for this non-constant and reader-specific difference.
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon, Cedex 09, France. burtona@fellows.iarc.fr.
authors.forename: Anya
authors.identifier: 0000-0001-7397-3442
authors.initials: A
authors.lastname: Burton
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon, Cedex 09, France.
authors.forename: Graham
authors.initials: G
authors.lastname: Byrnes
authors.affiliation: Centre for Genetic Origins of Health and Disease, Curtin University and the University of Western Australia, Perth, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Stone
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Rulla M
authors.initials: RM
authors.lastname: Tamimi
authors.affiliation: Moffitt Cancer Center, Tampa, FL, USA.
authors.forename: John
authors.initials: J
authors.lastname: Heine
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Celine
authors.initials: C
authors.lastname: Vachon
authors.affiliation: Department of Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Vahit
authors.initials: V
authors.lastname: Ozmen
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: Ana
authors.initials: A
authors.lastname: Pereira
authors.affiliation: Centre for Medical Image Computing, University College London, London, UK.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Garmendia
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Scott
authors.affiliation: Centre for Medical Image Computing, University College London, London, UK.
authors.forename: John H
authors.initials: JH
authors.lastname: Hipwell
authors.affiliation: Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Caroline
authors.initials: C
authors.lastname: Dickens
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon, Cedex 09, France.
authors.forename: Joachim
authors.initials: J
authors.lastname: Schüz
authors.affiliation: Marmara University School of Medicine Department of Radiology, Istanbul, Turkey.
authors.forename: Mustafa Erkin
authors.initials: ME
authors.lastname: Aribal
authors.affiliation: Slone Epidemiology Center, Boston University, Boston, MA, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Bertrand
authors.affiliation: Division of Breast Surgery, Department of Surgery, The University of Hong Kong, Hong Kong, People's Republic of China.|Department of Surgery, Hong Kong Sanatorium and Hospital, Hong Kong, People's Republic of China.
authors.forename: Ava
authors.initials: A
authors.lastname: Kwong
authors.affiliation: Cancer Epidemiology Centre, Cancer Council Victoria, Melbourne, Victoria, Australia.|Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Graham G
authors.initials: GG
authors.lastname: Giles
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Hopper
authors.affiliation: Cancer Epidemiology Unit, Instituto de Salud Carlos III and CIBERESP, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pérez Gómez
authors.affiliation: Cancer Epidemiology Unit, Instituto de Salud Carlos III and CIBERESP, Madrid, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Pollán
authors.affiliation: Breast Cancer Research Group, University Malaya Medical Centre, University Malaya, Kuala Lumpur, Malaysia.|Cancer Research Malaysia, Subang Jaya, Malaysia.
authors.forename: Soo-Hwang
authors.initials: SH
authors.lastname: Teo
authors.affiliation: Cancer Research Malaysia, Subang Jaya, Malaysia.
authors.forename: Shivaani
authors.initials: S
authors.lastname: Mariapun
authors.affiliation: Breast Cancer Research Group, University Malaya Medical Centre, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Nur Aishah Mohd
authors.initials: NA
authors.lastname: Taib
authors.affiliation: Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA.|Center for Research on Population Health, Instituto Nacional de Salud Pública, Mexico City, Mexico.
authors.forename: Martín
authors.initials: M
authors.lastname: Lajous
authors.affiliation: Center for Research on Population Health, Instituto Nacional de Salud Pública, Mexico City, Mexico.
authors.forename: Ruy
authors.initials: R
authors.lastname: Lopez-Riduara
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Rice
authors.affiliation: Section of Nutrition and Metabolism, International Agency for Research on Cancer, Lyon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
authors.affiliation: National Cancer Control Center, Haifa, Israel.
authors.forename: Anath Arzee
authors.initials: AA
authors.lastname: Flugelman
authors.affiliation: Cancer Registry of Norway, Oslo, Norway.|Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.|Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Giske
authors.initials: G
authors.lastname: Ursin
authors.affiliation: Norwegian Center for Minority and Migrant Health Research (NAKMI), Oslo, Norway.
authors.forename: Samera
authors.initials: S
authors.lastname: Qureshi
authors.affiliation: Department of Population Sciences, Beckman Research Institute, City of Hope, CA, USA.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Eunjung
authors.initials: E
authors.lastname: Lee
authors.affiliation: Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Sirous
authors.affiliation: Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mehri
authors.initials: M
authors.lastname: Sirous
authors.affiliation: Department of Surgery, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Surgery, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jisun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Cairo University, Cairo, Egypt.
authors.forename: Dorria
authors.initials: D
authors.lastname: Salem
authors.affiliation: Woman Imaging Unit, Radiodiagnosis Department, Kasr El Aini, Cairo University Hospitals, Cairo, Egypt.
authors.forename: Rasha
authors.initials: R
authors.lastname: Kamal
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, Singapore, Singapore.|Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: Mikael
authors.initials: M
authors.lastname: Hartman
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: Hui
authors.initials: H
authors.lastname: Miao
authors.affiliation: NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Kee-Seng
authors.initials: KS
authors.lastname: Chia
authors.affiliation: Gifu University, Gifu, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Nagata
authors.affiliation: Aga Khan University Hospital, Nairobi, Kenya.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Vinayak
authors.affiliation: Aga Khan University Hospital, Nairobi, Kenya.
authors.forename: Rose
authors.initials: R
authors.lastname: Ndumia
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Carla H
authors.initials: CH
authors.lastname: van Gils
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Johanna O P
authors.initials: JO
authors.lastname: Wanders
authors.affiliation: Nofer Institute of Occupational Medicine, Łódz, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Peplonska
authors.affiliation: Nofer Institute of Occupational Medicine, Łódz, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bukowska
authors.affiliation: Department of Imaging, Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Allen
authors.affiliation: Division of Cancer Research, Ninewells Hospital & Medical School, Dundee, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vinnicombe
authors.affiliation: Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK.
authors.forename: Sue
authors.initials: S
authors.lastname: Moss
authors.affiliation: Ontario Breast Screening Program, Cancer Care Ontario, Toronto, Canada.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Chiarelli
authors.affiliation: Princess Margaret Cancer Centre, Toronto, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Linton
authors.affiliation: University of Hawaii Cancer Center, Honolulu, HI, USA.
authors.forename: Gertraud
authors.initials: G
authors.lastname: Maskarinec
authors.affiliation: Medical Biophysics, University of Toronto, Toronto, Canada.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Yaffe
authors.affiliation: Princess Margaret Cancer Centre, Toronto, Canada.
authors.forename: Norman F
authors.initials: NF
authors.lastname: Boyd
authors.affiliation: Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Isabel
authors.initials: I
authors.lastname: Dos-Santos-Silva
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon, Cedex 09, France.
authors.forename: Valerie A
authors.initials: VA
authors.lastname: McCormack
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008327:Mammography / Q000379:methods*; D008875:Middle Aged
keywords: Breast cancer; Breast density; Image processing; Mammographic density assessment; Methods