1. Medical School Lecture
Breast Imaging
Medical School Lecture
November 18, 2015
Susan Peddle, MD
Assistant Professor
University of Ottawa
introduction and overview of the WBHC

2. Disclosure
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3. Overall Objectives
Review the background and evidence supporting the use of screening mammography, ultrasound (US) and magnetic resonance imaging (MRI)
Describe Canadian population‐based screening programs, their performance indicators and their costs
Provide an overview of mammographic abnormalities and their work‐up

4. Objectives Screening versus Diagnostic mammography BI-RADS
Review of mammographic abnormalities that warrant further work-up
Diagnostic work-up
Features of benign versus malignant lesions on ultrasound
Breast Intervention
Role of MRI in breast imaging
Current recommendations for breast screening

5. Objective 1
Screening versus Diagnostic mammography

6. Screening MG versus Diagnostic MG
Screening MG: to find cancers smaller than those detected at BSE or CBE
Sensitivity of BSE: Unknown
Sensitivity of CBE: Unknown
Sensitivity of screening MG: %
Diagnostic MG: to further evaluate a screen detected abnormality, symptom or clinical finding
Pain
Palpable lump
Nipple Discharge
Others (skin changes, nipple inversion, shrinking breast, enlarging breast)
BSE = breast self exam
CBE = clinical breast exam as performed by a medical professional

7. subareolar lactiferous ducts
Mammographic Anatomy
lymph node
skin
pectoralis muscle
vessel
glandular tissue
subareolar lactiferous ducts
Every breast has different a composition and relative amounts of fat versus more dense fibroglandular tissue
Our ability to detect abnormalities is dependent on composition
fat
inframammary fold
Cooper’s ligaments

8. Typical Mammography Unit

9. Routine Mammographic Views
MLO CC

10. We have to apply maximal compression, which only lasts momentarily, to obtain the best view and minimize overlap

11. MLO CC Outer quadrant Upper quadrant Inner quadrant Lower quadrant
goal of CC is to maximize visibility of medial breast 
techs document if patient anxious or would not allow compression
Inner
quadrant
Lower
quadrant

12. O’clock Position used for Localization
Right Breast
Left Breast
12:00
12:00
Lat
9:00
3:00
Med
Med
3:00
Lat
9:00
6:00
6:00

13. Technical Limitations
Breast Density
Patient anxiety, discomfort, physical limitations
Post-therapeutic changes
goal of mammo to pull out breast tissue - these things prevent that

14. Breast Density fatty replaced 0-25% scattered 25-50% heterogeneous
discuss how x-rays work
the reason we see things is because two tissues or variable densities are adjacent to each other
the best we have, but far from perfect
all MG reports comment on breast density to set the stage
heterogeneous
50-75%
extremely dense
75-100%

15. Objective 2
BI-RADS

16. BI-RADS Breast Imaging Reporting and Data System
Helps achieve uniformity in breast imaging reports which improves their clinical utility by communicating findings in a standardized way
Help determine clear management

17. BI-RADS 0: Needs further evaluation 1: Normal 2: Benign finding
3: Probably benign
4: Suspicious abnormality
5: Probable cancer
6: Biopsy proven cancer

18. 0: Needs further evaluation - additional mammographic views, +/- US, +/- MRI
1: Normal - Return to screening
2: Benign finding - Return to screening
3: Probably benign - > 98% likelihood of being benign. Short interval follow-up recommended in 6 months.
4: Suspicious abnormality - Biopsy needed
4A % likelihood of being malignant
4B % likelihood of being malignant
5: Probable cancer - Biopsy and surgical consultation needed (> 95% likelihood of being malignant)
6: Biopsy proven cancer

19. Objective 3
Review of mammographic abnormalities that warrant further work-up

20. 4 Main Mammographic Abnormalities
Microcalcifications
Architectural distortion
Mass
Asymmetries

21. Microcalcifications

22. Microcalcifications image
Microcalcifications can be an indicator of cancer, although they are often benign
Detected mammographically
Characterized by morphology (appearance), distribution, and change over time
Analysis helps radiologist determine the likelihood of underlying benign versus malignant pathology
image

23. Terminal Ductal Lobular Unit (TDLU)
Basic functional unit in the breast
Consists of acini that drain the terminal duct
Terminal ducts drain to larger and larger ducts, and eventually to the nipple

24. TDLU - site of origin of most cancers

25. Lobular Calcifications - form in acini - Intraductal Calcifications
- form in ducts -
Due to calcified cellular debris or secretions
Almost always benign
Suspicious for malignancy

26. Benign Calcifications
Skin
Coarse or “Popcorn”
Vascular
Rim or “Eggshell”

27. Suspicious Microcalcifications
“Variable in size, density and shape”
Fine Pleomorphic

28. Suspicious Microcalcifications
“Thin, linear or curvilinear irregular”
Fine linear or branching

29. Architectural Distortion

30. Architectural Distortion
Normal architecture is distorted with no definite visible mass
Look for abnormal straight lines or spiculations radiating from a point
Differential diagnosis:
Carcinoma vs scar tissue

31. Right - recurrence with IDC Left - IDC
prior lumpectomy on right
compare to previous very important
scar - increasing in density or changing in any way - further evaluation essential

32. Right - recurrence with IDC Left - IDC

33. Mass

34. Mass A space occupying 3D lesion seen in two different projections
3 important descriptive terms:
Shape
Margin
Density

36. Benign features Suspicious features Round or oval Circumscribed
Low density
Suspicious features
Irregular
Microlobulated, indistinct, spiculated
High density

37. Typically Benign

38. Typically Malignant

39. Asymmetries

40. Asymmetries
Unilateral deposits of fibroglandular tissue with NO mirror-image correlate in the opposite breast
A discrete mass is not seen on the initial MLO and CC views
True pathology versus overlapping normal tissue?

42. Asymmetry ??

43. Rt MLO
Lt MLO

44. Focal Asymmetry

45. Global Asymmetry

46. Objective 4
Diagnostic work-up

47. “Work-up”
Refers to additional testing required to determine the origin of an imaging or clinical abnormality
Comprised of additional mammographic views, US, MRI and/or biopsy

48. Abnormal
Mammogram
? True abnormality
Additional
mammographic views
? Mass
+/- Ultrasound
? Suspicious
+/- Biopsy

49. Additional Mammographic Views
Straight lateral or 90 degree view
Coned compression views
Magnification views
Pinched (Eklund) views
Rolled view
Extended CC view
Cleavage view
Tomosynthesis

50. Magnification Views
Performed for better characterization of microcalcifications
Focal spot = 1.6 times
2 views: CC and straight lateral (90 degree)

51. Lt MLO Magnification View Malignant Calcifications: Tightly clustered.
Vary in size and shape.
Bizarre branching irregular or linear forms
Typically found in DCIS and Invasive Ductal
When suspicious calcifications are the only sign of malignancy one may suspect DCIS but invasive ductal can not be excluded by mammography alone.
LCIS and Invasive Lobular Cancer do not typically calcify.

52. Coned Compression Views
Performed to differentiate normal overlapping parenchyma from a true abnormality

53. Coned Compression
Lesion does not persist on coned compression views in keeping with normal fibroglandular tissue

54. Coned Compression Views
Lesion persists on coned compression views in keeping with a true lesion

55. Ultrasound confirms the presence of a mass suspicious for malignancy

56. Tomosynthesis
- New technique created to produce a 3D picture of the breast using X-rays
- Designed to reduce overlapping tissues in mammography
- Results in high-resolution images at mammographic doses

57. Tomosynthesis 3D 2D Breast Reconstructed planes
If a 2 D image is taken the ovelapping structures, such as a cancer with normal breast tissue, will be difficult to differentiate from each other.
X-ray tube moves in an arc across the breast This may lead to false positives and false negatives.
With tomosnthesis, the exposures are obtained over a 15 degree arc , an exposure taken every 1 degree yielding 15 individual exposures
You need small angle for rapid scan without motion artifact. Objects at different heights in the breast are projected differently at different angles. Projection images are reconstructed to show 1 mm slices of breast tissue. This allows for separation of overlapping structures, and allows for accurate separation of lesions, permitting differentiation of true lesions from underlying tissue.
Reconstructed planes

58. Stationary breast platform X-ray tube swings during tomo
Breast tomosynthesis is an imaging technology that acquires 2D projection images of a compressed breast at multiple angles during a sweep of the X-ray tube.
ARC ABOVE THE BREAST

60. Tomosynthesis

61. Objective 5
Ultrasound features of benign versus malignant lesions

62. Ultrasound how US works - sound transmission real time visibility
allows physical examination at time of imaging

63. Benign vs Malignant Features

64. Simple Cyst Always benign Features: Anechoic (black) No wall
“Through transmission”
talk

65. Ultrasound Features of Solid Masses
benign - slow growing, so smooth, pushing borders
Classic benign
Classic malignan t

66. Benign Breast Lesions Well circumscribed - doesn’t invade
Wider than tall - obeys normal tissue planes
Thin echogenic pseudocapsule - compresses adjacent tissue
Gentle macrolobulations
Intensely echogenic - contains fat

67. Malignant Breast Lesions
Angular margins
Spiculations
Microlobulations
Taller than wide
Posterior shadowing
Ductal extension/Branch pattern
Microcalcifications

68. Margins: Angulated

69. Margins: Microlobulated

70. Ductal extension

71. Shadowing

72. Can we make the diagnosis of cancer based on ultrasound features only?

73. Case 1: 83 yo, palpable mass medial left breast
Case 2: 88 yo, palpable mass UOQ left breast

74. Case 1: 83 yo, palpable mass medial left breast
Case 2: 88 yo, palpable mass UOQ left breast
Cancer
Fibroadenoma

75. Invasive ductal carcinoma Involuted calcified fibroadenomas

76. Always start with a MG in women 35 years old and greater!

77. Objective 6
Breast Intervention

78. Breast Intervention
Tissue diagnosis mandatory for diagnosis of breast cancer
In the US, 1 million breast biopsies are performed annually to diagnose 200,000 breast cancers
Avoids unnecessary benign surgical excisions and allows surgeons to plan appropriate surgery in the setting of cancer
Extremely beneficial for patients and for the health care system in general
old school - patient had a lump and it was surgically removed
Not so now as our goal is to do the right surgery once to minimize the need for re-excision and to deal with the axilla ( a very hot topic) the first time
expedites adjuvant treatment - ie chemo or radiation post-operatively
cost of one biopsy is far less than the cost for a surgical excision in the OR

79. Breast Intervention How do we perform breast biopsies?
Ultrasound guided biopsy
Solid and complex solid-cystic masses
Stereotactic biopsy
Suspicious or indeterminate microcalcifications seen on MG
Persisting suspicious asymmetries on MG with no sonographic correlate
MRI guided biopsy
Lesions identified only on MRI with no mammographic or sonographic correlate
preference is US biopsy - fast, relatively cheap, more comfortable for patient and allows real-time visibility

80. Ultrasound Guided Biopsy

82. Fine needle aspiration
FNA
(uncommon)
CNB
VAD
Fine needle aspiration
Core Needle
Biopsy
Vacuum-assisted
Device

84. Core Biopsy

85. Vacuum Assisted Biopsy

86. Stereotactic Guided Biopsy

88. Technique Scout image taken to locate lesion in biopsy window
“Stereo Pair” obtained after moving x-ray tube +15° and −15° relative to 0° position
X, Y and Z (depth) coordinates calculated by computer
Lots of vendors are needles
Key - understand the basic physics of your device

91. Specimen radiograph confirms microcalcifications in the specimen
Final diagnosis: DCIS

92. Persisting focal asymmetry
Pre biopsy
Persisting focal asymmetry
Post biopsy

93. Deploy marker clip at the site of biopsy

94. Preoperative Image Guided Localizations

95. Preoperative Image Guided Localizations
Pre-operative localization is used to ensure complete excision of nonpalpable breast lesions
Localization device is inserted pre- operatively using mammographic or ultrasound guidance
Helps guide the surgeon in the OR, improving clear margin and breast conservation rates

96. MG or Ultrasound Guidance

97. 46 yo - Multifocal Disease UOQ

98. 2 wires inserted to guide surgical excisions

99. Radioactive Seed Localization
Low-dose I125 titanium prostate seed is placed at the target using mammographic or ultrasound guidance
Surgeon uses radioactivity probe to localize, dissect and remove breast lesion
Image courtesy of The Mayo Clinic

100. X-ray of lumpectomy specimen to confirm excision
Post-procedure mammogram confirms accurate seed placement adjacent to clip
X-ray of lumpectomy specimen to confirm excision

101. Objective 7
Role of MRI in breast imaging

102. Role of MRI in Breast Imaging
MRI has a high sensitivity
Main roles include:
High risk screening:
BRCA 1 and 2 mutation carriers
> 25% lifetime risk of developing breast cancer
Radiation to anterior chest wall for treatment of lymphoma
Local staging of breast cancer
Assess response to chemotherapy
Problem solving

103. 43 yo – BRCA1 carrier
June 20, 2012

104. Baseline Screening MRI
Bilateral breast cancer not seen mammographically
BILATERAL BREAST CANCER IN BRCA 1 GENE BASELINE MRI

105. Click View then Header and Footer to change this footer
Local Staging with MRI
MLO CC
Left breast
Clinical:
• Upper outer quadrant
• Palpable abnormality
MG:
• Pleomorphic microcalcifications
(BI-RADS 5)
Stereotactic Biopsy:
Final diagnosis: DCIS high grade
Click View then Header and Footer to change this footer

106. 2 min C+
MRI:
• Non mass enhancement (arrow)
• Additional retroareolar mass
(circle) for which US guided
biopsy was performed
Mastectomy and SLNB were
both performed
Final pathology: Invasive ductal carcinoma and ductal carcinoma in situ (DCIS)
(Total extent 8.0 cm)
2 min C+
2 min MIP

107. Assess response to chemotherapy with MRI
January 2012
July 2012
Post 6 cycles of chemotherapy

108. Objective 8
Current recommendations for breast screening

109. Current Recommendations for Screening
Who should have mammograms?
At what age should screening be initiated?

110. Benefits of Screening Mammography
- Reduction in breast cancer mortality by 40%
- Lower rate of mastectomy, radiation therapy and axillary lymph node dissection
- Less expensive treatment and less time off work

111. Limitations of Screening Mammography...”Harms”
False Negatives
10-20% of breast cancers are only detected at breast self-exam or physical exam
False Positives
Only 5-40% of lesions are detected at screening and recommended for biopsy
Over-diagnosis
11% of cancers found never progress
False positives - number of cases detected on screening which lead to biopsy but turn out to be benign
10% recalls per rad - 2% need biopsy
of those 40 % cancer, 60% benign - so 1.2% “unnecessary biopsies”

112. CAR Guidelines – Screening Mammography
Asymptomatic women years - Annual screening MG
Asymptomatic women years - Every 1-2 years
Women over 74 years - Every 1-2 years, if in good health
in accordance with ACR

113. When to Start Screening?
- CTFOPH recommends screening women and having a discussion about screening with women 40-49
- OBSP screens women 50-74
- Canadian Association of Radiology, American Cancer Society, National Comprehensive Cancer Network, American College Radiology, College Obstetricians and Gynecologists, recommend screening women
Canadian Task Force on Preventative Health - published in 2011
Extremely controversial and flawed - no breast cancer specialists; old, out-of -date machinery and single view mammograms used; epidemiologists
implementation of the CTFOPH guidelines may save money each year on screening costs, the result will be thousands of unnecessary breast cancer deaths

114. Should I Screen after age 74?
- For all ages, the mortality benefit from mammographic screening begins to be seen 5-7 years after the onset of screening
- Mammographic screening can be continued as long as there is reasonable expectation of a life expectancy of at least seven years
- Average life expectancy for an 80 year-old woman is 8.6 years which means that the healthiest quartile can be expected to live considerably longer

115. What is the Chance of Developing Cancer between 40-50 years old?
- 1 in 69 women will be diagnosed with invasive breast cancer in their 40s
- Breast cancer is the leading cause of cancer death in women < 50 years
- There is a very low incidence of breast cancer below age 30
There is no abrupt change at age 50
Annual U.S. breast cancer incidence rates per 100,000 women as a function of age for invasive + in-situ cancers

116. Numbers of Breast Cancers by Age
5% < 40 yrs
18% yrs
23% yrs
26% yrs
28% yrs
18% years
20% for every decade > 40 yrs
77% > 50 years
SEER, 2010,

117. No Role for Screening with Ultrasound
Average risk women - Screen with mammography
High risk patients - Screen with mammography and MRI

118. Objectives Screening versus Diagnostic mammography BI-RADS
Review of mammographic abnormalities that warrant further work-up
Diagnostic work-up
Features of benign versus malignant lesions on ultrasound
Breast Intervention
Role of MRI in breast imaging
Current recommendations for breast screening

119. Thank you
a special thanks to all the technologists at the breast centre for their expertise
I truly feel fortunate to work with such an incredible team