Any abnormality seen on the mammography is usually followed with a stereotactic breast biopsy - wherein a small sample of tissue is removed from the abnormal part of breast using a needle and the sample is later analyzed in the laboratory. A special computer is used to guide the needle to the spot of abnormality. Mammography and ultrasound help the radiologist trace the accurate spot to place the needle. This procedure is carried out on an outpatient basis and there is hardly any scar left behind following the procedure. An x-ray is taken to ensure that the right portion of the breast is centered to the window in the pad.
Breast density compares the amount of fat in the breast to the amount of tissue present. It is a measure used to describe mammogram images and is not a measure of how the breast feels (breast size and firmness). Breast tissue is made up of milk gland, milk ducts and supportive tissues (dense breast tissue) and fatty tissue (non- dense breast tissue).
Higher breast density indicates that the breast and connective tissue are denser when compared to the fat present in the breast. Lower breast density indicates more fat when compared to breast and connective tissue.
BIRADS or BI-RADS means Breast Imaging Reporting and Data System - a standard established by the American College of Radiology. This helps place findings from mammogram screenings into well-defined categories:
BI-RADS type 1: fatty; breast is almost entirely fat. Glandular tissue is less than 25%.
BI-RADS type 2: scattered fibroglandular; breast has scattered areas of fibroglandular density.
BI-RADS type 3: heterogeneously dense; breast tissue is heterogeneously dense.
BI-RADS type 4: dense; breast tissue is extremely dense. The breast contains greater than 75% glandular and fibrous tissue.
Dense breasts may be common and may not always pose a health issue. However women with high breast density are more prone to breast cancer when compared to women with low breast density. It is unclear as to why dense breasts may be more cancer prone. In a few cases women with low breast density are prone to develop breast cancer due to aging or menopause. 2/3 of pre-menopausal and 1/4 of post menopausal women (40%) have dense breast tissue.
A mammogram helps in identifying the density of breast. Women with dense breasts have more dense tissue than fatty tissue. Dense breasts look white or grey. Thus for women with dense breasts it may be difficult to identify cancer using a mammogram as both the dense breast tissue and cancer look grey or white in color in the image. Whereas for women with more fatty breasts it is easy to identify cancer as fatty tissues look black cancer look grey or white in color.
The 'success' rate of Mammogram detecting incidence of cancer depends on several factors:
In younger women with denser breasts, mammography is less sensitive than in older women with fatty breasts where mammography can detect at least 90% of malignancies. Smaller tumors especially those without calcifications are more difficult to detect especially in dense breasts. Diagnostic mammography is associated with higher sensitivity but lower specificity as compared to screening mammography.
Factors that affect breast density
Factors increasing breast density
Factors lowering breast density
Women with high breast density
Xeroradiography is an x-ray with enhanced image contrast and resolution on paper instead of film. Xeroradiography aids in visualization of soft tissues and is helpful in cervical spinal examination and mammography. This type of x-ray process needs more radiation exposure.
Bibliography / Reference
Collection of Pages - Last revised Date: March 23, 2019