mammmography Flashcards
1
Q
what is mammography?
A
- a modality that uses a low dose x-ray system to image the breasts
2
Q
types of breast imaging
A
- symptomatic
- screening
3
Q
symptomatic breast imaging
A
- 2 view mammogram
- triple assessment
- US better for under 40s
4
Q
breast imaging - screening
A
- 2 view mammogram - double read
- 50-70 years
- information on risks and benefits
5
Q
why is a Low kV technique used?
A
- breast tissue how low subject contrast and so a low kVp range increases subject contrast
- breasts are radiosensitive
- better visualisation of breast tissue of similar composition
6
Q
target materials in mammography
A
- molybdenum and Rhodium
7
Q
why are molybdenum and rhodium used as target materials
A
- can made into filters
- at low kV, emission spectra for these materials contain more low energy x-rays- more suited for breast tissue
- they can produce characteristic radiation
8
Q
what happens when we use the anode heel effect in practice
A
- there is an increased beam intensity and penetration of the chest wall and decreased penetration of the nipple edge
9
Q
how is additional filtration used to improve image quality
A
- absorbs the lowest and the highest x-ray energies, leaving only optimum x-ray energies to visualise the breast tissue ‘monoenergetic beam’
- enhances contrast sensitivity
- commonly used x-ray beam filters are molybdenum (Mo), rhodium (Rh), silver (Ag) and aluminium (Al)
10
Q
What does DBT stand for ?
A
Digital breast tomosynthesis
11
Q
what is DBT
A
- 3D mammography technique
- Reduces superimposition of overlapping breast tissue
- useful for dense breasts
- computerised reconstruction
- simple, efficient procedure
11
Q
what is DBT
A
- 3D mammography technique
- Reduces superimposition of overlapping breast tissue
- useful for dense breasts
- computerised reconstruction
- simple, efficient procedure
12
Q
what is DBT
A
- 3D mammography technique
- Reduces superimposition of overlapping breast tissue
- useful for dense breasts
- computerised reconstruction
- simple, efficient procedure
13
Q
effects of low kVp technique on radiation dose to the breast
A
higher mAs required/ more x-ray photons needed - this increases dose to the breast tissue/patient
14
Q
advantages of Digital Breast Tomosynthesis in the detection of breast disease
A
- good visualisation of dense and glandular breast tissue
- reduces superimposition of tissue of attenuations
- reduces the rate of false positives for lesions within the breast
- less need to biopsy
- relatively low dose investigation
- non-invasive
