Breast Imaging Flashcards
What types of imaging are part of the Triple Assessment in the Breast Clinic?
Mammography and US
How is the appearance of a lesion classified on imaging in the Triple Assessment?
1-5
5 being malignant
What is mammography?
- low density X-Rays
- breast is compressed to allow these to easily pass through
- provides contrast between tumour and fat
HOw many projections are used in mammography?
2 projections
- oblique
- craniocaudal (CC) => looking from top to bottom of pt
Describe what white and dark tissue represents on a mammogram
white - fibroglandular tissue
dark - adipose tissue
Where is most fibroglandular tissue (white on mammogram) found in the breast?
Mostly in lateral part of breast
Describe the sensitivity of mammography in a very fatty breast vs in a very dense breast
Fatty breast = HIGH
Dense breast = LOW (poor contrast)
Breast density increases with age. TRUE/FALSE?
FALSE
- breast density decreases with age
- this is not related to the menopause
What factors can change the rate at which breast density decreases?
- weight
- HRT use
- Tamoxifen use
Patients with a higher density breast are at higher risk of breast cancer in their lifetime. TRUE/FALSE?
TRUE
What are the advantages of mammography?
- images the whole breast at once
- high sensitivity for DCIS and invasive cancers
- has shown to decrease population mortality through its use in screening
- high reattendance rates to screening
What are the disadvantages of mammography?
- false positives
- overdiagnosis (cancer may be slow growing and not life threatening)
- ionising radiation
- uncomfortable for some women
Calcification may be identified on mammography at screening. What conditions can cause this?
- Duct ectasia
- DCIS
Tomosynthesis is a feature of mammography. What does it do?
Allows slices of breast to be imaged (like CT)
=> increases sensitivity
How can lesions be enhanced on mammography?
- Contrast
- Given IV
- Usually iodinated
- 2 images taken - 1 before and after contrast for comparison
What is US used for in the breast clinic?
- Confirm lumps seen on mammography
- If patient is symptomatic (e.g. palpable lump)
- image guided biopsy
- inflammation
- breast problems in pregnancy (mammogram not helpful here as breast is too dense)
What are the advantages and disadvantages of using US in the Breast Clinic?
Adv:
- not uncomfortable
- detects invasive cancer well
- can distinguish cyst from solid lump
Disadv:
- doesnt pick up DCIS as well as mammography
Contrast enhanced US is often used in the Breast Clinic. TRUE/FALSE?
FALSE not used very often
What is the purpose of elastography?
- measures stiffness of tissue
- cancers and their surrounding tissue are more likely to be stiff
- benign lesions (e.g. fibroadenoma) = very soft
What are the different probes used for elastography?
Strain Elastography (probe should be moved to assess lesion)
Shear Wave (probe remains still when assessing lesion)
Why are cancers usually stiff in comparison to benign pathology?
collagen in stroma becomes:
- disorganised
- poorly aligned
- lots of cross linking occurs
The interaction between the tumour and surrounding stroma is important in predicting spread and patient outcome. TRUE/FALSE?
TRUE
Tumours with what characteristics are usually stiffer than others?
- Node positive tumours
- Large tumours
- Tumours of high grade
- Lobular cancers
What are the advantages and disadvantages of MRI in braest cancer?
ADV:
- Most sensitive and accurate for sizing of lesion
DISADV:
- Shows tiny foci of cancers away from main lesion that prompt patients to have a mastectomy instead of wide local excision
Having a mastectomy as opposed to breast conservation and radiotherapy does NOT reduce the risk of recurrence. TRUE/FALSE?
TRUE
- Conservation and Radio is just as good if not better than mastectomy
What can MRI be used to investigate?
- Lobular cancer
- Cancer not picked up on mammography
- Pagets disease of the nipple (investigate underlying DCIS)
- Shrinking of cancer following neoadjuvant chemotherapy
- Imaging of positive axillary lymph nodes following normal mammogram/US
- Shows implant integrity (intra/extracapsular rupture)
Describe how a contrast activity/time graph shows a lesion is malignant rather than benign?
- Graph shows tumour rapidly filling with contrast and then “washing out” after a couple of mins
- benign or normal tissue has a slower increase in tking up contrast
What types of biopsy may be used in the Breast clinic?
- Core biopsy
- Vacuum biopsy
- FNA (not widely used now)
Why must a core biopsy be as large as a 14G needle?
breast tissue is friable
=> this size of needle allows a large enough intact sample
Core biopsy can be mammogram or US assisted. TRUE/FALSE?
TRUE
Describe how a Mammogram Assisted Core Biopsy takes place?
2 views used on mammogram to plan injection site
X marks the spot
XRay the biopsy sample afterwards to check the right bit has been taken
How large is a vacuum biopsy needle and what does this mean can be offered clinically?
11G needle
=> can offer to remove some lumps with this needle
=> e.g. papilloma as this can progress to cancer
What is the commonest breast cancer lump by age?
<30 fibroadenoma
30-50 simple cyst
>50 breast cancer
Why are cysts uncommon after the age of 50
women are post-menopausal => not going through the horomonal changes that would create a cyst
Describe the appearance of a cyst on US and how this would be treated
black - fluid
Tx = fluid drainage and reassurance
Describe the appearance of cancer on mammography?
- spiculated
- irregular margin
- lesion is taller than it is wide (benign lesions are the opposite as they are compressable by the US probe)
How is US used to assess axillary lymph nodes?
Used to measure cortical thickness and shape
- If over 3mm then biopsy
How should staging be carried out for breast cancer and where do metastases normally appear?
- local staging if disease appears to be operable
- CT chest, abdo, pelvis if worried about systemic spread
- Normal spread pattern: bone, lung, pleura, liver, brain
What breast conditions cause nipple discharge?
benign - duct ectasia
malignant - DCIS
What are the main causes of abscesses and inflammation in the breast? Which group of women are most at risk?
breastfeeding duct ectasia (older women)
women who smoke are most at risk due to poor healing
How is a breast abscess treated?
US guided drainage
antibiotics
What takes place during breast screening?
- Mammography alone
- for women aged 50-70 (extended trial elsewhere in UK)
- screened every 3 years
- Annual screening offered from age 40 if Moderate Family risk
- Annual MRI offered if HIGH risk (e.g. BRCA)
