6th International Workshop on Breast Densitometry and Breast ...

P12
6 th <strong>International</strong> <strong>Workshop</strong> on Breast Densitometry
and Breast Cancer Risk Assessment
COMPARISON OF CUMULUS MAMMOGRAPHIC DENSITY READINGS BETWEEN
FUJIFILM COMPUTED RADIOGRAPHY DIGITAL MAMMOGRAPHIC IMAGES IN
RAW AND DISPLAY FORMATS
Caroline Dickens, Valerie McCormack
Section of Environment and Radiation, <strong>International</strong> Agency for Research on Cancer, Lyon 69008,
FRANCE.
Background: The processing of digital mammograms from their raw to processed or display formats in
order to improve tumor detection involves manipulation of the image contrast by means of proprietary
image processing algorithms, which differ between vendors. It has been recommended that raw images
be used for estimation of mammographic density as they maintain image contrast, but in some instances
they are not available. Recent studies have shown a good correlation in percent breast density (PD)
between raw and processed images acquired using the General Electric Senographe FFDM
mammography units. We wished to see if similar comparability exists between PD readings performed
on raw and processed images obtained using the Fujifilm Computed Radiography (CR) imaging system.
ABSTRACTS
Methods: Bilateral raw and processed craniocaudal (CC) Fujifilm CR images were obtained for 100
women. Images were processed using the Fujifilm Image Intelligence algorithm. 400 images (100
women x 2 breasts x 2 formats) were anonymized and randomly sorted into 5 batches of 80 prior to
reading. PD was estimated by a trained observer (VM) using an interactive-threshold method (Cumulus3).
Comparisons of PD and absolute dense area between the raw and processed images were conducted using
Spearman’s rank correlation coefficient (r), t-tests for mean differences and kappa statistics for the
agreement of categories. Differences according to level of density were also examined.
Results: Minimum-maximum ranges (0-55% for raw and 0-58% for processed images) were similar in
the two image output formats, but processed images had a larger standard deviation (14.8 vs 12.8). Mean
PD was 22.8% (95% confidence interval (CI): 21.0, 24.6) for raw images and 25.9 (23.8, 27.9) for
processed images. Processed images had a mean PD 3.1 (2.0, 4.1) absolute percentage points higher than
in the corresponding raw image. For raw images with PD in the range