Tomosynthesis

• Multiple low dose exposures obtained in an arc and then fused together in 1 mm slices

• 3 images actually used

  • Raw images of the actual exposure

  • The fused raw images in 1 mm slices

  • Traditional Digital Mammogram or Synthesized Mammogram (these are basically post-processing images it seems)

• CAD = Computer Aided Detection - 2 types

  • CADe = D = Detection = Identifies Abnormalities

  • CADx = D = Diagnosis = Classifies Abnormalities

• Compression of breast during mammogram

  • Decreased radiation dose

  • Decreases blur by reducing exposure time and less time for pt motion

  • Reduces scatter = better image contrast

Views

Views

• View describes the direction of the XR beam

• Typical default included views include MLO and CC

• Other possible views include

  • Cleavage view

  • Exaggerated medial and lateral CC views

  • Others

Mediolateral Oblique (MLO)

• Beam travels from superior-medial to inferior-lateral

• Draw line from nipple to border of pectus muscle = posterior muscle line

  • This line needs to be within 1 cm of a line drawn from nipple posteriorly on the CC view

Terminology & Basics

• Multifocal = 2+ lesions in same quadrant or within 5cm of each other

• Multicentric = 2+ lesions in different quadrants or greater than 5 cm of each other

• Asymmetry

  • Regular Asymmetry = density seen only in one view that may or may not be a mass

  • Global Asymmetry = basically more breast tissue on one side relative to the other

    • “More” means at least one quadrants amount of asymmetry

    • If initial visit needs to be called back for another look to establish a baseline

  • Focal Asymmetry = lesion seen in 2 views but not further characterized by compression or mag views

  • Developing asymmetry = new lesion is there that wasn’t seen before basically

Plain Film Mammogram

• Lesions are described by shape, density and margin

• Shape

  • Oval

  • Round

  • Irregular

• Density (relative to background breast parenchyma, not fat)

  • Low

  • Equal

  • High

  • Fat (Classic ddx)

    • Lymph node

    • Hamartoma

    • Galactocele (if lactating)

    • Oil cyst

    • Fat encrosis

    • Lipoma

• Margin

  • Circumscribed

  • Obscured

  • Microlobulated

  • Indistinct

  • Spiculated

Blurring/Ripple Artifact

• Caused by limited # of acquired projections

• Occurs perpendicular to XR tube sweep direction

• Look for falsely thickened appearance of skin

• Coarse calcs and biopsy clips will have elongated slinky appearance

• Fix via post image processing

Motion

• Idk man

• Makes seeing calcs much harder

• Look for linear line of calcs, its really just one that is like dragged out

BR-3

• Things that can get a BR-3 on baseline exam

• Grouped or clustered round calcifications

• Asymmetry with interdispersed fat

• Fibroadenoma appearing lesion

US Descriptors

• Typically bs like echogenicity, shadowing

• Mammo-specific = orientation

• Orientation

  • Parallel (to chest wall) =typically more benign

  • Anti-parallel (to chest wall) = bad

TOMO Artifacts

Workflow

Lesion only seen on MLO?

• Get a true lateral

• You will evaluate whether the lesion is superior or inferior relative to the loction it was seen on the MLO

  • Use the nipple as your landmark on each

• If lesion is inferior on true lateral relative to the MLO then it is located in the lateral aspect of the breast (re-look at lateral on CC to see if you see anything)

  • Lead sinks = L = lateral

• If lesion is seen superior on lateral relative to MLO then the lesion is located in the medial aspect of the breast

  • Muffins rise = M = medial

Mass only seen on CC?

• Basically means you see how deep the mass is but not if it is in the superior or inferior breast

• Get a rolled CC view

• Mass is in superior compartment

  • Mass will move the same way you move the breast

  • Roll breast medially, mass will move medially

  • Roll breast laterally, mass will move laterally

• Mass in inferior compartment

  • Mass will move the opposite way you move the breast

  • Roll breast medially, mass will move laterally

  • Roll breast laterally, mass will move medially

BI-RADS

BI-RADS Classification

• BI-RADS 0 = Incomplete assessment

• BI-RADS 1 = Negative

• BI-RADS 2 = Benign finding

  • To call BI-RADS 2 on a baseline need at least 3 masses with at least 1 in each breast

• BI-RADS 3 = Probably benign

  • Round calcs or lesions on baseline exam

  • 2% chance of malignancy

• BI-RADS 4 = Suspicious (2-95% chance of malignancy)

  • If you made it a BI-RADS 4 lesion, you have to biopsy it, if the biopsy comes back as benign you can leave it alone

• BI-RADS 5 = Highly suspicious mass (>95% chance of malignancy)

  • If you make it BI-RADS 5 something, you have to biopsy it, if the biopsy comes back as benign then you HAVE to have a surgical excision of the lesion

• BI-RADS 6 = path proven

Calcifications

Ductal

• Dash-dot-dash = no good

• Concerning fro DCIS

Amorphous Calcifications

• Basically multiple calcs but can’t actually make out how many, just a bunch

• Hazy and indistinct

• DDx

  • Fibrocystic change = most likely

  • Sclerosing adenosis

  • Columnar cell change

  • DCIS - low grade

Fine Linear Branching

• Very bad

• DDx

  • Atypical vascular or secretory calcs

  • DCIS

Distribution

Architetcural Distrotion

• DDx

  • Malignancy - IDC-NOS, ILC

  • Radial Scar

  • Post-surgical scar

Biopsies

• 3 types

  • US (core)

  • Stereotactic

  • MRI

• 90% of pathology can be diagnosed with a single first biopsy with a good tissue sample

• With all biopsies but most relevant for US guided

  • Want the needle to be parallel to the chest wall (muscle below the breast tissue)

  • Want to biopsy the deeper portion first before the shallower portion

  • In complex masses (contain cystic and solid components), need to biopsy the solid part, not the cystic part

• If biopsing a mass that is adjacent to a breast implant and you cannot safely biopsy it without the high risk of rupturing the implant, then try a stereotactic biopsy because you can do an implant displaced view and then biopsy it

Architectural Distortion