Lecture 4 - Breast Imaging

What is the sensitivity and specificity of mammogram

Sensitivity: 75-85%

Specificity: 90-97%

What is mammography effective for

• Masses

• Architectural distortion

• Asymmetries

• Suspicious calcifications

What’re the views in mammography

CC: cranial caudal

MLO: medial lateral oblique

Why is multimodality imaging important in mammography

• Pathology may appear different in different modalities

• US can determine if mass is solid/fluid filled

• Dose justification - young patients may be referred to MRI/US

• Breast density

What’re some ways breast pathology can present

• Asymmetric lesion - on one boob but not the other

• Architectural distortion

• Calcifications

• Smooth wall benign lesions

• Invasive irregular wall lesions

• Malignant lesion with lymph node, skin or nipple changes

What’re the 4 quadrants for lesion localisation

5: upper outer

6: upper inner

7: lower outer

8: lower inner

What’re the regions for lesion localisation

Which shape is benign/malignant

Oval: benign

Irregular: malignant

Which margin is benign/malignant

Circumscribed: benign

Spiculated: malignant

Which density is benign/malignant

Low: benign

High: malignant

Which orientation is benign/malignant

Parallel: benign

Non-parallel: malignant

Which echogenicity is benign/malignant

Anechoic: benign

Hypoechoic: malignant

Heterogenous: malignant

Which posterior acoustic feature is benign/malignant

Enhancement: benign

Shadowing: malignant

What’re some common benign masses

• Cyst

• Fibroadenoma

• Intramammary lymph node

• Lipoma

• Hamartoma

What’re the characteristics of a benign fibroadenoma

• Fibrous non-cancerous solid growth

• Painless

• Smooth wall

• Common

Name this pathology

Benign bibroadenonma

What’re the characteristics of a benign breast cyst

• Fluid filled sac

• Painful and affected by menstrual cycle

• Can be aspirated

• Better seen on US - determine nature of cyst

Name this pathology

Breast pathology

What’re the characteristics of micro calcifications

• Benign

• Tec cups

• Pearls

• Vascular markings

What’re the characteristics of malignant microcalcifications

• Clustered

• Irregular shape and size

Benign or malignant

• Likely malignant

• Poorly defined spiculated mass

• Dense

Benign or malignant

• Likely malignant

• Defined spiculated mass

• Dense

What kind of mass is this

Stellate mass (invasive lobular carcinoma with radiating margins)

What kind of mass is this

Invasive ductal carcinoma (NOS)

What extra view can you preform in mammography

Spot view

What is breast density

• Relative amounts of fibroglandular tissue and fatty tissue

• more fibroglandular tissue = more dense

How does far appear in mammograms

Dark

How does fibroglandular tissue appear on mammograms

White

What are the BI-RADS density categories

A: Almost entirely fatty

B: Scattered areas of fibroglandular density

C: Heterogeneously dense

E: Extremely dense

How does breast density affect mammography

• Dense tissue can obscure malignancy

• Dense tissue and cancer appear radiopaque

• Breast density is a risk factor for breast cancer

What is the masking effect

Similar cancer within a dense breast

What’re imaging options for dense breast

• Breast tomosynthesis

• US

• Contrast enhanced mammography

• MRI

Describe tomosynthesis

• Multiple low-dose projections across angular range

• Images reconstructed into thin slices

• Reduces tissue superimposition compared with conventional 2D mammography

• MLO and CC

What’re the advantages of tomosynthesis

• Reduces tissue overlap

• Improves cancer detection and lesion characterisation

• Particularly useful in dense breasts

• Reduces recalls and false positives

• Provides better lesion localisation

What’re the disadvantages of tomosynthesis

• Longer interpretation time

• Larger image storage requirements

• Higher cost/additional training needs

• Higher radiation dose when combined with2D mammography

• Potential motion artefact

What is a needle biopsy

Needle is used to draw sample fluid and small amounts of tissue from a lump

What is a core biopsy

Needle is used to scoop out tissue sample - gives more information

What is a lumpectomy

Surgeon removes lesion only

What is a mastectomy

Whole breast is removed

What is the dose of mammography comparable to

• Flight from Australia to London

• 3 months of natural exposure

Positioning for CC view

• Boob is centred in the middle with the nipple in profile

• Pec muscle seen indicating that the boob has been positioned as far forward

• Medial and lateral portions of breast seen

• Well compressed and well exposed

Positioning for MLO view

• Boob pulled forward and the parenchyma is spread out

• Pec muscle is seen as wedge down to the level of the nipple

• Nipple in profile

• Abdominal wall is includes