Comprehensive Mammography Notes

Breast Cancer Statistics and Risk

• Breast cancer is presented as the highest cancer mortality rate for women in the United States in this transcript, which motivates screening programs.
• Lifetime risk: about $12.5\%$ for every person assigned female at birth. This risk is discussed as a baseline unless there are other known factors.
• Hormonal influence: monthly estrogen surges (menstrual cycle) contribute to a higher risk of breast cancer.
• Men and breast cancer: men have a risk < $1\%$; however, men can and do get breast cancer, often at more advanced stages due to delayed presentation.
• Hormone therapy: hormone replacement therapy or other hormonal factors can increase breast cancer risk (the slide/text notes an increased risk but specifics are not filled in).
• Family history: while it increases risk, most people who develop breast cancer do not have a significant family history. A risk assessment is performed at each mammogram to gauge individual risk.
• Screening impact: screening mammography reduces breast-cancer mortality by about $30\% - 40\%$.
• Disparities: In Virginia, black women have the highest rate of mortality from cancer among Black women in the state, indicating gaps in screening and access that need to be addressed.
• Screening guidance and start age: there is variation in guidelines, with the American Cancer Society recommending screening starting at age $40$ and annual; some agencies propose starting at $50$. The speaker personally has had a mammogram every year after age $40$.
• What screening achieves: screening can reduce mortality by early detection; mammography screenings are a key tool in catching cancers earlier when treatment outcomes are better.

Benefits and Practical Aspects of Mammography

• Mammography detects lesions as small as < 2\text{ mm} in some cases (early detection).
• Safety and practicality: mammography is considered safe, allows yearly imaging, and is relatively noninvasive and inexpensive (a few hundred dollars) compared to MRI (which can cost $2{,}000 - 3{,}000$).
• 3D vs 2D context: while not explicitly comparing all figures, there is a discussion of how three-dimensional (3D) mammography (tomosynthesis) and 2D imaging interplay to improve detection and reduce false positives.
• Microcalcifications: 3D imaging can reveal tiny calcifications that are important for early cancer detection.
• Early detection rationale: finding cancer when it is smallest and easiest to treat correlates with better outcomes.

Mammography Equipment and Imaging Principles

• Breast anatomy and image quality concepts:
  • Compression is used to flatten the breast for consistent X-ray attenuation and to improve detail.
  • The aim is to spread tissue apart to reduce tissue superimposition that can mimic lesions.
  • Digital image receptors are standard today; traditional film-screen mammography was largely replaced by digital systems (with a historical note about transitioning up to 2007).
• X-ray tube orientation and rationale:
  • The mammography tube is oriented to optimize penetration of thicker tissue near the chest wall; this influences the geometry of the setup.
• Parameters controlling exposure:
  • kVp (kilovoltage peak): determines the voltage driving the X-ray tube and influences image contrast.
  • mA or mA×s (tube current and exposure time): determines the number of X-ray photons produced.
  • The goal is to adjust kVp and mA to obtain adequate image quality with appropriate contrast and dose.
• Compression device and patient experience:
  • The compression plate/towel (compression device) is the component patients often dislike; sensitivity to compression varies widely among patients. Some patients tolerate it well; others require a gentler, slower approach.
  • Compression aids in consistent attenuation and reduces tissue thickness, improving image clarity while reducing dose and motion.
• Image quality concepts:
  • Object-to-image receptor distance (OID) affects magnification and distortion; reducing OID improves sharpness and resolution.
  • Scatter radiation adds grayness to images; reducing tissue thickness (via compression) reduces scatter and improves image contrast.
  • Achieving uniform density across the image helps in accurately assessing lesions.

Views for Screening Mammography

• Cranial-Caudal view (CC):
  • Beam travels from superior to inferior; visualizes anterior breast tissue, central/medial portions, and posterior medial portions.
  • The nipple should be centered; pectoral muscle may not always appear in the image. If the pectoral muscle is visible, it indicates adequate inclusion of tissue.
  • The breast is positioned between a compression paddle and the imaging plate.
• Mediolateral Oblique view (MLO):
  • The beam is angled to visualize the upper outer quadrant and portions of central/medial tissue; aims to include tissue that CC view may miss.
  • Arm is raised and positioned to allow visualization of the pectoral muscle down to the nipple line.
  • The MLO view is essential to capture tissue behind the nipple line and the retroglandular fat space.
• Rationale for two views:
  • As with other radiographic exams (e.g., ankle), two views are necessary to avoid missing pathology due to orientation.
• Subtle positioning cues:
  • In some images, the nipple may appear retracted due to positioning; this may warrant a repeat view.
• Notes on anatomy seen in views:
  • The pectoral muscle visibility in MLO helps assess the amount of tissue captured; the goal is to include this region for accurate assessment.

Breast Tissue Types and Age-Related Changes

• Glandular tissue vs fatty tissue:
  • Glandular tissue is the functional tissue for milk production; in younger and premenopausal women, glandular tissue is more prominent.
  • With age and in postmenopausal women, glandular tissue often atrophies and is replaced by fatty tissue.
• Variation among individuals:
  • Women vary widely in tissue composition; breast tissue can be very dense or largely fatty.
• Clinical implications:
  • Dense glandular tissue can obscure lesions on imaging; this is one reason for adjunctive imaging (e.g., 3D mammography, ultrasound, MRI) in certain cases.
• Gender/biological variations:
  • Hormonal influences can lead to glandular development in men (rare) under certain circumstances; medications and hormones can cause men to develop glandular tissue and potentially require imaging.
• Transgender considerations:
  • The speaker references research on mammography experiences among transgender individuals and the broader context of breast imaging in diverse populations.

3D Tomosynthesis vs 2D Mammography

• 3D imaging basics:
  • The machine rotates the X-ray tube by about $\pm 15^\circ$ on either side, acquiring multiple slice-like images that are reconstructed into a 3D volume.
  • A synthetic 2D image can be generated from the 3D dataset to reduce radiation dose while maintaining diagnostic utility.
• Benefits of 3D imaging:
  • Reduces tissue overlap, enabling better visualization of calcifications, vascular structures, and subtle lesions (e.g., a stellate lesion with spiky extensions).
  • Reduces false positives, which lowers patient anxiety and reduces unnecessary biopsies.
  • Saves some cases where a previously seen lesion on 2D may be resolved or clarified in 3D.
• Trade-offs and dose considerations:
  • A 3D mammogram alone has a dose roughly comparable to a 2D study, but combining 3D with a 2D image increases dose; advances include synthetic 2D generation to minimize dose when appropriate.
• Practical examples from the transcript:
  • A case where a lesion seen on a 2D image but not clearly seen the following year became visible with 3D imaging, highlighting the value of DBT when subtle findings are present.
• Spot compression and targeted imaging:
  • 3D imaging can be supplemented by spot compression to isolate a region of interest, though it can be uncomfortable for patients; a smaller compression paddle is used here.

Lesions, Calcifications, and Diagnostic Clues on Mammography

• Calcifications:
  • Tiny calcifications can indicate early cancer; their pattern and distribution (e.g., casting-type, dots, linear clusters) influence the level of concern and the need for biopsy.
• Stellate lesions:
  • Lesions with “fingers” extending into surrounding tissue suggest a more suspicious pattern, especially when seen with high tissue distortion on imaging.
• Other findings:
  • Lymph nodes in the axilla may appear enlarged or abnormal and can warrant biopsy if cancer is suspected.
  • Vascular calcifications may resemble tubular patterns; interpretation requires correlation with clinical context.
• Benign entities:
  • Oil cysts (lucid center, smooth outline) are typically benign.
  • Hamartoma (breast within a breast) is benign but can mimic inflammatory processes.
  • Fibroepithelial tumor (phyllodes tumor) is rare; most are benign but some can be malignant.
• Ductal pathology and nipple changes:
  • Intraductal papilloma (inside ducts) can cause nipple discharge and may be benign or malignant.
  • Ductography can reveal ductal abnormalities that explain discharge; a catheter is inserted to image the ductal system with contrast.
• Painful or unusual findings:
  • Nipple retraction or unusual nipple positioning on MLO views can indicate underlying tissue changes and may require additional views.
  • Paget’s disease is a rare skin/Nipple condition with characteristic appearance on imaging and clinical exam.

Biopsy Techniques and Localization Procedures

• Core biopsy basics:
  • Ultrasound-guided core biopsy uses large bore needles (gauge range $7-16\text{ gauge}$). Tissue is sampled from targeted areas; anesthesia is typically local, though patient comfort varies, and some patients may experience fainting.
  • Multiple samples (e.g., four samples) are often taken from different areas to ensure representative tissue is collected.
  • After biopsy, a metallic clip (approximately titanium) is placed at the biopsy site to mark the area for future reference.
• Rationale for biopsy sequencing:
  • A biopsy is performed to obtain a definitive diagnosis before considering more invasive surgery.
  • If cancer is confirmed, subsequent steps may include localization procedures prior to surgery.
• Needle localization before surgery (wire localization):
  • A wire can be placed through the lesion to guide the surgeon, either under mammography or ultrasound guidance.
  • In some cases, radioactive or electronic seed localization is used.
  • The patient then proceeds to surgery with the wire or seed enabling precise surgical targeting.
  • Specimen radiography is performed after surgical excision to confirm that the targeted lesion was removed.
• Ductal procedures and other guidance:
  • In some cases, ductal imaging and interventions are performed to assess and address nipple discharge or other ductal abnormalities.

Implants and Imaging Challenges

• Implants and visibility:
  • Saline vs silicone implants; saline implants are generally radiolucent and easier to visualize; silicone can be more challenging to see on X-ray.
  • Implants can be placed in front of the pectoral muscle or behind it; implants in front can obscure underlying breast tissue, making imaging more difficult.
• Imaging strategies with implants:
  • When implants are behind the muscle, compression can be used to separate the tissue and obtain clearer images, similar to imaging without implants.
  • Displacement views (compression/shift of the implant) are used to better visualize the breast tissue surrounding the implant.
• Practical notes:
  • In some cases, minimal or no compression is used to prevent implant damage, particularly in views focusing on implant assessment.

Ductography, Ductal Pathology, and Special Imaging

• Ductography (ductography):
  • A catheter is inserted into a duct to evaluate ductal anatomy and pathology relevant to nipple discharge.
  • Contrast dye is injected to visualize the ductal system under imaging, allowing detection of filling defects or ductal abnormalities that could explain discharge.
• Ductal findings:
  • Filling defects and other abnormalities within ducts can be detected via ductography, aiding diagnosis of underlying pathology.

Clinical and Ethical Considerations in Mammography Practice

• Patient-centered care: the “dance” between technologist and patient highlights the need to tailor handling to individual patient comfort and stress response during the exam.
• Gender considerations: there is discussion about male mammographers and patient comfort; most patients prefer female technologists for breast imaging, and there is a note about changing attitudes and practices to improve comfort.
• Service learning and global health:
  • The speaker describes participating in service trips (e.g., Rad Aid International, teaching breast biopsy techniques in India) as an example of professional service and global health engagement.
• Professional anecdotes:
  • Anecdotes about the variability in patient responses to compression and the emotional weight of images (e.g., a cousin with cancer, the emotional difficulty of retrospective finding).
  • The importance of documenting biopsy sites (clips) so that future imaging can correlate to prior biopsy areas and guide treatment.

Practical Takeaways for Exam Preparation

• Remember the core purpose of screening: to detect cancers early when treatment is more effective; the benefit includes a reduction in mortality and the possibility to treat earlier with better outcomes.
• Key imaging concepts:
  • Compression improves exposure, reduces motion, reduces dose, reduces tissue overlap, and improves lesion detection by spreading tissue apart.
  • 3D tomosynthesis reduces overlap and improves detection, with synthetic 2D imaging used to limit dose when appropriate.
  • Views: CC (cranial-caudal) and MLO (mediolateral oblique) views with the imperative to include nipple, pectoral muscle, and retroglandular fat space where possible.
• Biopsy workflows:
  • Ultrasound-guided core biopsy with 7-16 gauge needles; clip placement; specimen radiography to confirm removal; and localization procedures before surgery when cancer is detected.
• Ductal assessment:
  • Ductography for nipple discharge; catheterized ducts with contrast visualize the ductal system to detect filling defects.
• Implants:
  • Imaging strategies differ for implants; displacement views and careful consideration of compression are necessary to optimize imaging without damaging implants.
• Population health and equity:
  • Awareness of disparities in cancer mortality and screening utilization, especially among Black women in Virginia, and the importance of community outreach and screening access.
• Personal and ethical reflection:
  • The discussion includes emotional and ethical dimensions of providing care, handling sensitive patient situations, and maintaining patient trust and comfort in the breast imaging setting.