Chapter 20 - Breast Imaging (BEANS NOTES) Flashcards
2 purposes of breast imaging?
- Screen asymptomatic women for early breast CA
2. Evaluate breast abnormalities in symptomatic pxs or pxs with indeterminate screening mammo
National cancer institute (NCI) advises women at average risk for breast CA who are age ___ and over should undergo screening mammo every __ to __ years.
40, 1 to 2 years
American Cancer Society Guidelines for breast CA screening:
> Age 20-39, clinical examination every 3 years, mammo not recommended
Age 40 and over, clinical examination annually, mammo annually
Factors known to increase a woman’s risk of breast CA:
- Personal history of breast Ca
- Laboratory evidence that women is a carrier of the BRCA1 or BRCA2 genetic mutation
- Having a mother, sister or daughter with breast CA
- Atypical or precancerous lesions diagnosed on a previous beast biopsy
- Nulliparity or having a first child at age 30 or older
Goal of screening asymptomatic women?
To find breast CA in its earliest stages
Minimum size of breast CA that can be felt on PE?
1.5 to 2 cm.
Other imaging technologies use in breast CA detection and diagnosis?
> UTZ > MRI > PET > Tomosynthesis > CT
The gold standard and single best test for early detection of breast CA?
Mammography
A __________ resulting from percutaneous FNAB can look similar to a small CA.
Hematoma (Best to perform a ff.up mammogram after 4-6 weeks later)
Women under age _____ should not undergo mammography.
20
Optimal mammography
High contrast and high spatial resolution.
Anode material utilized to generate the xrays in most dedicated mammography?
Molybdenum
Some units also have __________ that can be used to increase the contrast in denser breasts while keeping radiation dose and time of exposure low.
Rhodium anodes
Uses an electronic system for image capture and display. It has a higher contrast resolution and equal or better dynamic range than film screen mammo. Spatial resolution is lower.
Full-field digital mammo (FFDM)
Advantages of FFDM:
> higher speed of image acquisition > ability to perform image processing > integration of computer aided detection and diagnosis software programs > electronic storage > possibility of teleradiography
The standard views for screening mammography are:
MLO and CC views.
What view depicts the greatest amount of breast tissue and it is the most useful view in mammography?
MLO view
Classic signs of malignancy?
Spiculated masses or pleomorphic clusters of microcalcifications
Localizing lesion seen in one view. Demonstrate milk of calcium due to gravity dependency.
90 degree lateral (ML or LM)
Determine whether lesion is real or is a summation shadow.
Spot compression
Better definition of margins of masses and morphology of calcifications.
Spot compression with magnification (M)
Show lesions in outer aspect of breast and axillary tail not seen on CC view.
Exaggerated craniocaudal (XCCL)
Show lesions deep in posteromedial breast not seen on CC view.
Cleavage view (CV)
Verify skin lesions. Show palpable lesions obscured by dense tissue.
Tangential (TAN)
Verify true lesions. Determine location of lesion seen in one view by seeing how location changes.
Rolled views (RM or RL)
Improved visualization of superomedial tissue. Improved tissue visualization and comfort for women with pectus excavatum, recent sternotomy, prominent pacemaker.
Lateromedial oblique (LMO)
Improve visualization of native breast tissue in women with implants.
Implant displacement (ID)
Mammographic features of mass
> convex borders > denser towards the center > distort the normal breast architecture > seen in multiple projections > can still be visualized when focal compression is applied.
Artifacts that resemble masses on mammography can be produced by overlapping breast tissue.
Summation artifacts
The following must be assessed once the radiologist concluded the presence of mass.
Margins, density, location and size
Most important characteristics to be assessed?
Margins
Classically appears as spiculated mass on mammo
Breast CA (majority are infiltrating ductal CA)
_________ from previous surgical biopsy can appear spiculated
Fat necrosis
Scars from previous breast surgery should be carefully marked with __________
Radiopaque wires
These are spontaneous lesion that are benign and consist histologically of central sclerosis and varying degrees of epithelial proliferation, represented by strands of fibrous connective tissue. Can also present as a spiculated lesion.
Radial scar or complex sclerosing lesion
Most commonly seen in subareolar location in lactating women. Clinical findings of pain, swelling and erythema.
Breast abscesses
Seen in women on anticoagulation therapy or in those with blood dyscrasias. Can also be secondary to trauma, needle aspiration or surgery.
Spontaneous hematomas
Most common well-circumscribed masses seen in women between the ages of 35 and 50 years. On utz, they are round or oval, smooth walled and anechoic.
Cysts
Another manifestation of fibrocystic change that can be seen mammographically. Appears as well-defined mass on the films. Sometimes may present with ill-defined borders.
Fibrosis
Most common well-defined solid masses. Hypoechoic masses on utz. Peak age is 20-30 years
Fibroadenomas
Primary breast malignancies when a well-defined density is visualized on mammography.
- Infiltrating ductal CA
- Papillary CA
- Mucinous CA
- Medullary CA
Most common primary CA to produce breast metastasis.
Melanoma
Benign breast lesions that are purely fat density includes the ff:
Oil cysts (from fat necrosis), lipomas and sometimes galactoceles
Cyst that generally result from trauma.
Round lucent lesions surrounded by a thin capsule, often multiple and can demonstrate rim calcifications
Oil cyst
Similar to oil cyst, also lucent with surrounding capsule.
Surrounding breast architecture may be distorted because of the mass effect
Lipomas
Occur in lactating or recently lactating women and are probably the result of an obstructed duct.
Galactocoeles
Benign masses that are mixed fat and water densities.
Rare benign tumors and intramammary lymph nodes.
Generally located in the UOQ in the posterior 3/4 of the breast parenchyma
Hamartomas
Intramammary nodes are almost always located in the _________
UOQ of the breast
Skin lesions are usually recognized by ________ around the edges or in the interstices. These can produce a dark halo around one edge.
Air trapping (will not be evident with flat, pigmented skin lesions or sebaceous cysts)
View to demonstrate that the lesion is located in the skin.
Tangential view
Size upper limit of _________ for masses that are to undergo follow-up.
1 to 1.5 cm (6month ff.up of the affected breast followed by bilateral mammogram 6 months later then annual mammo for at least 3 years to document stability)
Calcification pattern in primary breast cancer in mammography.
Clustered, pleomorphic microcalcifications.
Dystrophic
Large calcifications with lucent centers that are benign
Eggshell calcifications in oil cyts
Calcifications in the wall of tortuous vessel
Arterial calcifications
Magnification of a 90degrees lateral mammo showing diffuse linear calcifications and in CC view of the same area shows smudged, rounded calcifications. Appears as a line of meniscus when views from the side in lateral projection.
Milk of calcium in breast cysts
Long and thick calcifications in ectatic ducts that radiate toward the nipple
Secretory calcifications
Indeterminate calcifications are most often associated with ________
Fibrocystic change (fibrosis adenosis, sclerosing adenosis, epithelial hyperplasia, cysts, apocrine metaplasia and atypical hyperplasia)
Biopsy of indeterminate calcification will yield a diagnosis of _______
LCIS (lobular carcinoma in situ)
Malignant calcifications are generally less than ______
<0.5mm
Causes of increased density of breast tissue
Hormone therapy, inflammatory CA, radiation therapy, diffuse mastitis, obstruction to the lymphatic or venous drainage
Bilateral increased density is usually the result of estrogen replacement therapy in postmenopausal women.
Hormone therapy
Unilateral increase in breast density with associated skin thickening
Inflammatory CA
Unilateral increase in parenchymal density with skin thickening can also be seen in patients who have undergone radiation therapy to the breast.
Radiation therapy
Generalized skin thickening and increase in breast density
Diffuse mastitis
From metastatic disease, surgical removal, or thrombosis can produce a unilateral increase in breast density with skin thickening due to edema.
Obstruction to the lymphatic or venous drainage
Axillary lymph nodes are frequently visualized on the ______ mammogram. Normally, they are ________ in size and have lucent centers or notches resulting from fat in the hilum.
MLO, <2cm
Benign or normal lymph nodes are ______ with a ________ on UTZ.
Hyperechoic, thin hypoechoic cortical rim
Screening mammography in the women with implants requires the use of at least 2 extra views of each breast.
Standard MLO and CC plus implant displacement views (2)
First examination performed in pxs noticing a change in implant contour or size and if women is older than 30 years
Mammography (not useful in the detection of intracapsular silicone implant ruptures)
Most accurate in identifying silicone implant rupture and in localizing free silicone.
MR (IR most effective sequence)
Indicates intracapsular rupture occurs when the collapsed implant shell floats within the silicone gel contained in the fibrous capsule.
Linguine sign
Indicates small amounts of silicone collected in a radial fold. Overtime, microscopic silicone can leak through the intact implant shell and collect at the implant shell surface giving a subcapsular line sign.
Noose, teardrop or keyhole signs
Most common indication for breast imaging in men.
Palpable asymmetric thickening or mass (gynecomastia is usually the cause)
Generally appears as a triangular or flame shaped area of subareolar glandular tissue that points toward the nipple
Gynecomastia
Male breast in mammo
Mound of subcutaneous fat without glandular tissue
Common clinical applications of breast MR
Screening of pxs at high risk for developing breast CA, preop staging of newly diagnosed breast CA, detection of mammographically occult malignancy in pxs with axillary nodal mets, evaluation of response to neoadjuvant chemotherapy.
Breast MR technique
1.5 Tesla or higher, px in prone position with breast hanging into a dedicated receiver breast coil, should be done between days 6 and 17 of the menstrual cycle.
Predictors of benignity in MR
Smooth margins, non-enhancing internal septations, minimal or no enhancement, and diffuse patchy enhancement
Features suggestive of malignancy in MR
Spiculated or irregular borders, peripheral or rim enhancement, segmental or regional enhancement, and ductal enhancement
Most invasive CA demonstrate rapid initial enhancement with a _____ or _____ on delayed imaging.
Plateau, washout
May demonstrate slow initial enhancement
DICS, invasive lobular CA, tubular CA, mucinous CA
BI-RADS
Breast Imaging Reporting And Data System (for mammo, breast UTZ and MR)
BI-RADS Category 0
Need additional imaging evaluation and/or prior mammogram for comparison
BI-RADS Category 1
Negative
BI-RADS Category 2
Benign finding (lipoma,oil cyst, galactocoele, intramammary LN, hamartoma, fibroadenoma, cyst etc.)
BI-RADS Category 3
Probably benign-initial short interval ff.up suggested
BI-RADS Category 4
Suspicious abnormality-biopsy should be considered
BI-RADS Category 5
Highly suggestive of malignancy-appropriate action should be taken
BI-RADS Category 6
Known biopsy proven malignancy-appropriate action should be taken
Interventional procedures for the breast
Percutaneous biopsy, image directed core biopsy and aspiration
The tip of the needle for a wire localization should be ______ beyond the lesion.
1 to 2 cm
Most useful in guiding a localization when the abnormality is seen well in one projection but is obscured by dense tissue in the second
Ultrasound
Can be used to investigate the cause of a spontaneous nipple diacharge. Most frequently lesions are papillomas.
Ductography
