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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, screenfilm 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)