Anya Burton, International Agency for Research on Cancer
Graham Byrnes, International Agency for Research on Cancer
Jennifer Stone, Curtin University
Rulla M. Tamimi, Harvard Medical School
John Heine, Moffitt Cancer Center
Celine Vachon, Mayo Clinic
Vahit Ozmen, Istanbul University
Ana Pereira, University of Chile
Maria Luisa Garmendia, University College London
Christopher Scott, Mayo Clinic
John H. Hipwell, University College London
Caroline Dickens, University of the Witwatersrand
Joachim Schüz, International Agency for Research on Cancer
Mustafa Erkin Aribal, Marmara University
Kimberly Bertrand, Boston University
Ava Kwong, The University of Hong Kong
Graham G. Giles, The University of Melbourne
John Hopper, The University of Melbourne
Beatriz Pérez Gómez, Instituto de Salud Carlos III and CIBERESP
Marina Pollán, Instituto de Salud Carlos III and CIBERESP
Soo-Hwang Teo, University Malaya
Shivaani Mariapun, Cancer Research Malaysia
Nur Aishah Mohd Taib, University Malaya
Martín Lajous, Harvard T.H. Chan School of Public Health
Ruy Lopez-Riduara, Instituto Nacional de Salud Pública
Megan Rice, Harvard Medical School
Isabelle Romieu, International Agency for Research on Cancer
Anath Arzee Flugelman, National Cancer Control Center
Giske Ursin, University of Oslo
Samera Qureshi, Norwegian Center for Minority and Migrant Health Research (NAKMI)
Huiyan Ma, Beckman Research Institute
Eunjung Lee, University of Southern California
Reza Sirous, Isfahan University of Medical Sciences
Mehri Sirous, Isfahan University of Medical Sciences
Jong Won Lee, Asan Medical Center
Jisun Kim, Asan Medical Center
Dorria Salem, Cairo University
Rasha Kamal, Cairo University
Mikael Hartman, National University of Singapore
Hui Miao, National University of Singapore
Kee-Seng Chia, National University of Singapore
Chisato Nagata, Gifu University
Sudhir Vinayak, Aga Khan UniversityFollow
Rose Ndumia, Aga Khan UniversityFollow
Carla H. van Gils, University Medical Center Utrecht
Johanna O. P. Wanders, University Medical Center Utrecht
Beata Peplonska, Nofer Institute of Occupational Medicine
Agnieszka Bukowska, Nofer Institute of Occupational Medicine
Steve Allen, Royal Marsden NHS Foundation Trust
Sarah Vinnicombe, Ninewells Hospital & Medical School
Sue Moss, Queen Mary University of London
Anna M. Chiarelli, Cancer Care Ontario
Linda Linton, Princess Margaret Cancer Centre
Gertraud Maskarinec, University of Hawaii Cancer Center
Martin J. Yaffe, University of Toronto
Norman F. Boyd, Princess Margaret Cancer Centre
Isabel dos-Santos-Silva, London School of Hygiene & Tropical Medicine
Valerie A. McCormack, International Agency for Research on Cancer

Document Type



Imaging and Diagnostic Radiology (East Africa)


Background: 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.

Methods: 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.

Results: 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 cm2 respectively, 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.

Conclusions: 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.

Publication (Name of Journal)


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