Mammograms work best on fatty breasts because they have fewer areas of density (lighter masses). Breast masses which usually cause concern are lighter than normal dense tissue. Young women, especially those who have not had children, usually have dense and rather firm breast tissue. Mammography equipment can be adjusted to image dense or fatty tissue, but are most accurate on fatty tissue.
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Source:
Dr. Dwight Kaufman. Diagnosis: Mammogram: Normal Fatty National Cancer Institute. February 1994.


