11. Breast Imaging Flashcards
Mammography in breast imaging
considered the gold standard; for screening and microcalcifications
Ultrasonography in breast imaging
- useful in younger women
- solid vs. cystosus mass
- regional lymph nodes
MR in breast imaging
- occult tumor search
- multiplicity
- scar vs. recidive tumor
- chest wall infiltration
Nuclear medicine in breast imaging
- sentinel lymph nodes
- preoperative labeling
CT in breast imaging
- not suitable for primary breast cancer detection!!
- staging for distant metastases and lymph node status
PET-CT in breast imaging
- not suitable for primary breast cancer detection!!
- staging for distant metastases and lymph node status
- disadvantages: low spatial resolution, non-FDG avid breast tumors
Breast tissue composition
- glandular tissue shows strong hormone dependency and changes during lifetime
- type depends on constitution, age and possible additive hormonal therapy
- at younger ages the breast is more glandular and then becomes more fatty
Sensitivity of mammography according to breast type
- fatty breasts shows small cancer more easily (higher sensitivity)
- even large cancers are difficult to detect for glandular breasts (higher risk of undetected tumor)
What are the main mammography views?
- craniocaudal (CC): upper part is the outer quadrants and the lower part is the inner quadrants
- mediolateral oblique (MLO): upper part is the upper quadrants and the lower part is the lower quadrants
Digital breast tomosynthesis
- less superimposition and better sensitivity
- In dense breasts tomosynthesis has higher sensitivity than 2D mammography
Most important signs of malignancy on mammography
- asymmetric density
- microcalcifications
- architectural distortion
relatively high proportion of carcinomas are localized to the upper outer quadrant of the breasts
What are some unique signs of malignancy on mammography?
- tent sign: mall pulls on the posterior contour of the breast
- skin thickening
- peau d’orange sign (skin appear orange)
- retraction of nipple (usually with spiculated mass)
Breast calcificiations on mammography
calcifications can be reliably evaluated only on breast mammography
- macrocalcifications are usually benign lesions
- clustered polymorph microcalcifications are always alarming and should be clarified
- popcorn calcification: fibroadenoma
- eggshell calcification: oil cyst
Strengths of breast mammography
- excellent spatial resolution
- detection of microcalcification
- cheap, available
- fast
- additional views
- suitable for breast with implants
- digital technique
- computer aided detection (CAD)
- stereotaxix biopsy
Weaknesses of breast mammography
- ionizing radiation
- decreased sensitivity in dense breasts
- discomfort due to compression
- superimposition
- skilled mammographers are required
What transducer is used for breast US?
high frequency (8-18 MHz) linear transducer
What are the regional lymph nodes checked on breast US?
- axillary, parasternal, infraclavicular and supraclavicular (poor prognosis)
- great for US-guided biopsy
What are the strengths of breast US?
- good spatial resolution
- no ionizing radiation
- cheap, available
- repeatable
- can be performed during lactation
- great tool in dense breasts
- regional lymph ode visualization
- solid vs. cystic differentiation
- US-guided biopsy
What are the weaknesses of breast US?
- low sensitivity for microcalcifications
- hard to detect early signs
- not ideal for screening
Significance of MRI studies in breast imaging
- important for the staging of cancer and evaluation of response to neoadjuvant therapy
- provides functional information using MR contrast-enhancement dynamics
- washout pattern is considered to strongly suggest malignancy - US shows suspicious sign but MR gives a definitive diagnosis
What are the strengths of breast MR?
- good spatial resolution
- non-ionizing
- sensitive
- 3D
- iv. contrast enhancement kinetics
- differentiation b/w scar and recurrent tumor
- chest wall infiltration
- multiplicity, bilateral lesions
- implant rupture detection
- MR-guided interventions
What are the weaknesses of breast MR?
- false negative for microcalcifications
- not suitable for screening
- expensive, limited availability
- MRI-contraindications
- lower specificity (false positives)
- cannot substitute biopsy
What is the BI-RADS classification?
- scoring system for risk assessment
- based on mammography, US and MR signs
- according to the score, subsequent management of the lesion is decided
BI-RADS 3: FNAB is an option
BI-RADS 4: Core biopsy is mandatory
Which modality to choose for screening breast imaging?
- screening breast imaging is in case of asymptomatic patients
- mammography
- annual screening is recommended as early as age 25 in case of BRCA1/BRCA2 mutation
