Imaging the breast Flashcards
When is imaging of the breast indicated?
Symptomatic patients:
¥ Lumps
¥ Unilateral or blood-stained nipple discharge
¥ Skin tethering or dimpling
¥ Signs of inflammation
¥ Axillary lumps
¥ NOT for pain; tenderness; symetrical nodularity!
Screening
What is mammography?
¥ A low dose xray designed specifically to maximise contrast between the breast tissues, whilst minimising radiation dose
What are the BIRADS parenchymal patterns seen on mammography
¥ a: nearly all fat
¥ b: scattered fibroglandular densities (25-50%)
¥ c: heterogeneously dense (51-75% glandular)
¥ d: extremely dense (> 75% glandular)
What are features of malignant calcification?
¥ Distribution - cluster or segmental vs. scattered or diffuse
¥ Cluster shape/size - rhomboid forms
¥ Individual particle shape -linear/branching/Y shaped forms
¥ Pleomorphic nature - size/density
How is a calcification assessed?
¥ Mammography ¥ microfocus magnification - ML, mag cc and lat ¥ tangential views (skin calcifications) ¥ digital manipulation - contrast, zoom ¥ Ultrasound ¥ MRI?? – not if you can biopsy it!
When is USS indicated?
¥ Characterisation of mammographic findings - differentiation of cystic and solid lesions
¥ Palpable lesions, women < 40y
¥ Nipple Discharge
¥ Breast Implants or augmentation
¥ Other - inflammatory conditions (abscesses)
¥ Evaluation of response to chemotherapy
What do cystic lesions look like on USS?
¥ Cysts: fluid collections
¥ Shape, contents, internal echoes
¥ Clustered cysts
¥ Complex cysts
can use US guided aspiration
What do benign solid nodules look like on USS?
¥ Circumscribed ¥ Hypoechoic/hyperechoic ¥ “Wider than Tall” ¥ Homogeneous ¥ Peripheral/no vascularity ¥ Often Multiple
What do malignant solid nodules look like on USS?
¥ Poorly Circumscribed ¥ Hypoechoic ¥ Heterogeneous ¥ “taller than wide” ¥ Spiculate ¥ Oedema/peritumoral fat (blurriness surrounding it)
What is elastography?
this is a new US technique based on tissue compression indicating how ‘stiff’ a tissue is. ¥ MRI based elastography ¥ US based elastography: ¥ sonoelasticity (vibration) ¥ single/multi-step compression ¥ compression devices ¥ freehand method ¥ shear wave elastography
What is a vacuum assisted biopsy?
use device to create vacuum and suck up biopsy with help of USS
Why is MRI breast needed?
• Mammography has limitations:
o sensitivity in dense breasts ( 55%)
o Limited contrast inherent in technique- up to 15% ca’s mammographically occult
o Observer limitations
o High % indeterminate lesions needing biopsy
o Compression, irradiation
• US has limitations: o Operator-dependent o Time-consuming o Reproducibility o Misses calcifications o Unproven in screening - false positives and negatives
• MRI: o Excellent intrinsic tissue contrast o Multiplanar tomographic capacity o No compression o No ionising radiation o Accuracy independent of breast density
When is MRI used in breast ?
Malignant disease: postcontrast scans
¥ i.v gadolinium based contrast
¥ Rapid dynamic imaging of entire breast
Accuracy:
morphological pattern – can see shape temporal pattern - can see how the contrast moves in time
Look for enhancement and neovascularity:
- More enhancement in malignancy
- More neovascularity = correlation with tumour grade and risk of met.s
Contraindications to MRI breast
¥ Absolute – as for any other MR exam
(cardiac pacemakers, ferromagnetic aneurysm clips, cochlear implants, renal impairment etc.)
¥ Relative – pregnancy, lactation
(effect of gadolinium based contrast, increased background breast enhancement)
Indications for breast MRI
Benign disease:
¥ implants (integrity) – gold standard for implants
¥ problem solving (lesion characterisation)
Malignant disease: ¥ diagnosis (occult 1° breast cancer) ¥ staging and treatment planning ¥ residual disease post WLE ¥ response assessment - chemotherapy ¥ recurrent disease – breast, reconstructed breast, axilla
screening – high risk groups (genetic) annually
¥ 30-49 yrs with >30% probability of BRCA
¥ 30-49 yrs with known BRCA
¥ 20-49 yrs with >30% probability of TP53
¥ 20-49 yrs with known TP53 mutation
