Types and Techniques:
• Screening mammography - it is done to detect cancer at an early stages or when it is small. Usually recommended for people of age 40.
• Diagnostic mammography - it is an x-ray examination of breasts for people who complain for presence of lump or nipple discharge. It is done to determine the exact size and location of breast abnormalities. It is more expensive than screening.
• Film screen mammography - in this technique images will be present on large sheets of film in black and white color.
• Digital mammography - in this technique images are recorded directly, viewed, specific areas can be enlarged with the help of computer. It delivers 3/4th of radiation that film- screen do. Digital images can be stored more easily but it is expensive.
Who & When to get a mammogram???
• Generally for women above age 40 every year it is recommended.
• People of age around 30 with strong family history of breast or ovarian cancer.
• Who have undergone radiation treatment in the past.
• It can detect breast cancer at an early stage before spreading.
• It can decrease death from breast cancer in women between age of 40-49.
• In women of age 50-69 mammogram can decrease rate of death by treating the breast cancer immediately after identifying it.
• It is the single most effective method for detection of breast cancer at an early stages.
• The main risk is that they are not perfect.
• Radiation form routine mammography has risks of initiating and promoting breast cancer.
• Premenopausal women undergoing annual screening over ten year period are at a higher risk to get breast cancer because of radiation treatment.
• Breast cancers risks from mammogram are 4-fold higher in women (2%) which are carrier of Ataxia-Telangiectasia (A-T) gene.
• It entails tight and painful compression of breast leading to distant spread of malignant cells by rupturing small blood vessels in premenopausal women.
• For pregnant women it is not safe as high amount of radiation will effect the developing foetus.
• False positive - in this mammogram identifies an abnormality that looks like cancer but it turns out to be normal.
• False negative - in this normal tissue hides the breast cancer and is not shown in mammogram.
• Firstly the patient is asked to remove all jewelry and clothing and asked to wear a gown.
• A small x- ray skin markers are placed on the skin.
• Then the patient is positioned, and one breast at a time is rested on a flat surface that contains x-ray plate.
• A device called compressor is pressed firmly against the breast that flattens out the breast tissue. Due to this compression there may be discomfort for some seconds, but this helps in obtaining mammogram and images with good resolution. Without using compressor images will be blurred.
• Do not use deodorants, powders, antiperspirants. Usage of these cause images foggy, and stimulate the appearance of micro calcifications.
• Generally two X- rays are taken during mammogram and a person who takes mammogram is called radiologists.
• Digital mammography save time and confusion for radiologists.
Various skin markers are used for mammogram, include
• Beekley skin marker - in this pellet is used and it indicates nipple
• S-shaped marker - it indicates surgical scar
• Traingular marker - indicates worrisome mass or lump
Views of mammogram:
Images are taken at various angles during mammogram these include:
• Cranio-Caudal view (CC) - it is taken from above
• Mediolateral- Oblique (MLO) - it is taken from side at an angle diagonally compressed to breast
• Lateromedial - taken from outside towards the centre
• Cleavage view - in this both breast are compressed to see tissue nearest at center of chest
• Spot compression - it is taken to get more detail on a small area
Radiologists look for irregular areas of increased density, clusters of sm all calcifications, asymmetries, skin thickening areas. Most of the time radiologists cant say surely whether its cancer or not.
So, radiologists use CAD (Computer Aided detection) and diagnosis software for detection of suspicious areas on mammogram. By using this images of suspicious areas are analyzed, highlighted with markers on the screen.
BI-RADS (Breast Imaging Reporting and Database System)
It is the system for assessment of Mammogram developed by American College of Radiology.
Assessment categories are,
0. Incomplete it needs additional imaging and evaluation and need to gather more information
1. Negative, there is no significant or noticeable abnormality in the report
2. Benign findings like calcifications, fibro adenoma are present but not cancerous
3. Probably benign findings
4. Suspicious abnormality, findings that turn out to be cancer
5. Highly suggestive of malignancy, findings look like cancer
6. Known biopsy, findings prove to be cancer by biopsy