What are the two main puposes of mammography
May be performed either for diagnosis of a clinical finding or for screening of women aged 50-70 yrs in UK
How is the mammography machine set up to reduce exposure to the body
The machine is angled so that the x-ray beam diverges on the breast tissue
why is compression applied to the breasts
To spread out the breast tissues, reducing dose and scatter, it also immobilises the breast reducing movement unsharpness (blur) and spread out over lapping tissues, making it easier to differentiate between normal and abnormal structures.
Outline the stages of breast development
what are the two standard projections used in mammography
- Cranio-Caudal (CC)
- Medio-Lateral Oblique (MLO) (45-55 degrees)
Which of the two standard projections is shown here
Cranio-Caudal
Give another projection which might be used in mammography
- Medial-Lateral – 90 degree lateral (sometimes Lat-Med used)
- Compression spot views in any projection
- Magnified spot (x2, x1.5)
- Tangential views
- Eklund technique for implants
Outline the mammography procedure-CC
- Patient stands at medial edge and rests against faceguard (protective cone.)
- Elevate breast to ensure minimal drag from compression and raise or lower C-arm to comfortable position.
- Breast pulled forward to include medial edge and as much lateral edge tissue as possible.
- Nipple in profile but not to the detriment of the posterior breast tissue. One view must have nipple in profile or a second nipple view must be taken.
- Compression applied
- Mirror images required (see next slide)
- Semi-circles on compression plate indicate automatic exposure device position.
Why are images presented back to back
Images must be mirror images as this aids film reading easier to pick up asymmetric densities
Outline the mammography procedure- MLO
- Assembly adjusted to individual physique, slim woman steeper 50-60 degrees, average angle 45-55 degrees Nipple must be in profile otherwise could hide SAR lesion.
- Corner of detector in posterior border of axilla.
- Lift breast towards medial and superior borders, to afford better compression and lessen painful drag on the breast.
- Eliminate skin folds as could easily hide calcification.
- Compress until taut if woman comfortable. Increased pressure beyond this contributes very little to the image. Some women will have more sensitive or dense breast tissue increasing the discomfort of a mammogram.
What symptoms may mean someone is referred to the breast clinic
What is gynaecomastia
- Men can develop increase in glandular tissue forming a breast lump, known as gynaecomastia
- commonly occuring in puberty and old age
- can be caused by used of steroids, illegal drugs, prescribed medication
- can be related to prostate problems, therefore the patient will also undergo a blood test.
- Caution must be taken as <1% of breast cancers occur in men.
What does the breast clinic triple assessment contain?
- Clinical examination
- Breast imaging (mammography +/- US)
- Ultrasound first >40
- Biopsy
- If any significant findings
The aim of the NHSBSP is to reduce mortality from breast cancer by …?
- Inviting women between 50 and 70 years (+ age expansion trial)
- High quality, two view, bilateral mammography
- Three yearly
- Timely recall for assessment
- Identification of small breast cancers
- Prompt referral if cancer diagnosed
Why are women over 70 allowed to self-refer
Increased risk of breast cancer with age
In 2017, how many breast cancers were identified by screening
A total of 18,001 women aged 45 and over had cancers detected by the screening programme in 2017-18, a rate of 8.4 cases per 1,000 women screened.
Possible disadvantages of screening general public
- Increased risk of radiation induced cancers
- Not 100% sensitive: Small cancers can hide in dense tissue/ may not be seen maybe mammographically occult/may be minimal sign only detected in hind sight
- Cancer may occur in women even with regular breast screening
- Increased anxiety for women waiting for results
- High levels of false positives
- Potential over treatment
What happens if a potential abnormality is identified at screening
the patient will be recalled to a static unit for triple assessment. This includes similar processes to the symptomatic patient – Further imaging (+/- US), clinical examination and biopsy.
What are the breast cancer 5 stages
What are the most common breast pathologies
What are the most common imaging abnormalities in breast tissue
- Asymmetry
- Architectural distortion
- Masses
- Calcification
describe calcifications
- Calcification can have typically benign or malignant features
- the number of particles, size of the particles and/or the cluster, shape and distribution are all considered
- many can not be characterised by imaging appearances alone and require core biopsy.
What other imaging modalities may be used to help identify breast pathology
- Tomosynthesis (slices through breast tissue like CT)
- Ultrasound
- MRI
- Contrast enhanced spectral mammography (similar contrast medium to CT, then mammograms taken at difference kVp levels)
- PET – CT? (pick up as an incidental finding)
- Molecular breast imaging- good at showing function but not sizes/characteristics of cancers
How often do women aged between 50 and 70 come for breast screening
every 3 years
