AbstractID: 8521 Title: Exposure Factors Used In A Large Mammographic Screening Program - Twelve Year
Analysis
Exposure Factors Used In A Large Mammographic Screening
Program - Twelve Year Analysis
Since 1990 the Ontario Breast Screening Program (OBSP) has been recording the technique factors used
for imaging the first forty patients of every month at each of their facilities for each of the four standard
mammographic views (LCC, RCC, LMLO, RMLO). As of the end of April 2002, this has resulted in nearly 300,000
records - one per 4-film patient exam. While much can be learned from measurements made on phantoms, these data
provide a picture of how mammography is actually performed on women. For example, information on average
breast compression force and compressed breast thickness can be examined. These data can also be correlated with
OBSP physics testing and evaluation reports in order to obtain approximations of entrance exposure and mean
glandular dose. In this presentation, trends over time and across screening sites using different mammography units
and image receptors will be examined.