RAD 254 Chapter 19 Mammography Also known as soft tissue radiography Breast CA is the 2nd leading cause of cancer related death in women (lung CA is first) 1 in every 8 women will get breast CA
Two types of Mammo Screening – for asymptomatic patients Diagnostic – for symptomatic or elevated risk patients Baseline Mammo is the first mammo done and is usually done prior to the age of 40
Risk factors for Breast CA Age – the older the higher risk Family history – mom/sister with breast CA Genetics – presence of BRCA1/2 genes Menstruation – onset prior to age 12 Menopause – after age 55 Late childbirth age or no kids Education – higher ed = higher risk Socioeconomics = higher risk with higher status
Breast anatomy all similar atomic mass density Fibrous Glandular – most radiosensitive breast tissue Adipose – less dense and less dose If a malignancy is present, it usually presents as a distortion of ductal and connective tissue patterns. 80% is ductal and many have microcalcifications
Imaging breast tissues Low kVps – 23-28 kVp Target material is tungsten (W), molybdenum (Mo) or rhodium (Rh) Filter material is dictated by target material Beryllium or borosilicate If tungsten target – then molybdenum or rhodium filter Inherent filtration is approx. 0.1 mm Al equiv. Focal spot sizes 0.3-0.1(large/small)
Other mammo info Heel effect is always used (chest wall at cathode side of tube) Compression always used : increased spatial resolution, lower patient dose and focal spot blur Grids are usually 4:1 or 5:1 FOCUSED AEC’s require reproducible images at low dose kVp’s of +/- 0.1 OD
Mammo Image Receptors Historically there have been many receptors used (direct-exposure, xeroradiography, screen-film and digital receptors) Current are only screen-film and digital receptors in this country Digital’s advantage is post image acquisition Processing; disadvantage is spatial resolution limitations (pixel size of receptor)