7. Mammography
• Mammography is a radiographic examination
that is designed for detecting breast
pathology ( particularly breast cancer ).
Breast cancer screening with mammography
assists in detecting cancer at an earlier, and is
an important clinical procedure because
approximately one in eight women will develop
breast cancer over their lifetime.
12. Mammography X-Ray Tube
Target materials consist of three main types.
• Molybdenum
• Specialized Tungsten
• Rhodium
• Molybdenum
– the best material to be used in mammography,
– allows production of low energy spectrums of radiation
– low kVp (26-40kVp)
• Tungsten and Rhodium are used for higher beam needs, in
dense breast tissues.
13. Filtration
• Materials that are placed in the path of the X-ray
beam in order to absorb those X-rays with
energies above and below the desired spectrum.
• Tube filtration types:
• Molybdenum (Mo) (best used for lower kVp)
• Rhodium (Rh)
• Yttrium
• Aluminum (used for above 30 kVp)
14. Collimation
Collimator – used to shape radiation field :
• Recall, smaller radiation field means less
scatter, collimate when you can!
• Smaller exposed area, better for patient
dose
18. Cont.…
• Better spatial resolution. The breast is brought
closer to the imaging receptor so that
magnification and focal spot blurring is reduced.
• Reduced movement blur, even at the relatively
long exposure times.
• Less scattered radiation in the image. The beam
path length through the breast is shorter, so there
is less material to do the scattering.
19. Cont.
• The reduced path length makes practicable
the
use of lower energy (less penetrating) X-ray
spectra. This gives greater subject contrast.
• Small areas of pathology buried in glandular
tissue can be better visualized, as malignant
tissues tend to be firmer.
20. Breast support plate
• It’s the plate that hold the breast :
• Two parts:
• Upper part made from carbon fiber(free
absorption)
• Lower part made from lead (safe the
patient abdomen from radiation hazard )
23. Advances
1. Digital mammography:
• also called full-field digital mammography
(FFDM), is a mammography system in which
• the x-ray film is replaced by solid-state
detectors that convert x-rays into electrical
signals.
24. Advances
2. computed aided detection:
• that can be obtained from either a conventional
film mammogram or a digitally acquired
mammogram.
3. breast tomosynthesis:
• also called three-dimensional (3-D) breast imaging,
is a mammography system where the x-ray tube
moves in an arc over the breast during the exposure.
25. 1. THE ESSENTIAL PHYSICS OF MEDICAL IMAGING,
THIRD EDITION.
2. CHESNES’ EQUIPMENT FOR STUDENT
RADIOGRAPHERS FOURTH EDITION.
References :
Breast cancer screening with mammography assists in detecting cancer at an earlier, and is an important clinical procedure because approximately one in eight women will develop breast cancer over their lifetime.
Breast cancer screening programs depend on x-ray mammography because it is low-cost, low-radiation dose procedure that has the sensitivity to detect early-stage breast cancer.
Mammography requires x-ray detectors with high spatial resolution that function best at higher doses.
Enhancing contrast sensitivity, reducing dose, and providing the spatial resolution necessary to depict microcalcifications impose extreme requirements on mammographic equipment and detectors.
Mammographic techniques present two technical challenges which conventional, general purpose, x-ray equipment is unable to meet. First, the anatomical site and shape of the breasts makes their isolation more difficult than most other parts of the body. Second, the breast is composed of tissues which are markedly more radiolucent than most other structures within the body and which, in their composition, contrast with each other to a very limited extent.
Therefore, dedicated x-ray equipment, specialized x-ray tubes, breast compression devices, antiscatter grids, x-ray detectors ( screen-film or digital ), and phototimer detector systems are essential for mammography.
Screening mammograms are x-ray exams of the breasts that are used for women who have no breast symptoms or signs of breast cancer .
The goal of a screening mammogram is to find breast cancer when it’s too small to be felt by a woman or her doctor .
A woman with a breast problem (for instance, a lump or nipple discharge) or an abnormal area found in a screening mammogram typically gets a diagnostic mammogram. Sometimes diagnostic mammograms are done for screening in women without breast problems who were previously treated for breast cancer.
