SON 2147 Sonogrpahy of the Breast Part II Module Four Mammography Holdorf PhD, MPA, RDMS (Ob/Gyn, Ab, BR), RVT, LRT(AS)

Module Four - Mammography

American Cancer Society Guidelines Breast Self-Examinations (BSE) Performed monthly by women of all ages Clinical Breast Examination (CBE) Performed by a physician Every 3 years for women 20 to 40 Every year for women over 40 Mammography Baseline study of women 35-40 After age 40, mammogram very year

Breast Exam Guidelines One of the best weapons against breast cancer is early detection. There are many ways to examine the breast for the presence of disease. The American Cancer Society offers guidelines for routine examinations of the breast.

Breast Self-Examination The Breast Self-Examination (BSE) includes visual inspection and palpation of the breasts in both an upright and supine position. A fibrous ridge is a prominent area of glandular tissue easily palpated. This is often mistaken for a mass.

Clinical Breast Examination The Clinical Breast Examination (CBE) is performed by the patient’s physician. Most breast cancers are found by either BSE or CBE.

Mammography Mammography is currently the most important breast imaging method. As a screening tool, it has proven to be highly effective in the diagnosis of breast cancer. On average, mammography will detect 80 to 90% of breast cancers in women with symptoms. A mammogram is made by directing radiation through the breast tissue onto a film or digital detector. The breast tissues absorb and scatter the x-rays at varying degrees. Radiologists who interpret mammograms look for patterns made up of dark gray, light gray, and white to detect breast disease. Mammography does not detect all breast cancers, but it detects more small breast cancers than any other method.

To obtain high quality mammograms at the lowest radiation dose possible, the mammography equipment must be properly inspected and maintained. Breast imaging standards of the Mammography Quality Standards Act of 1992 (MQSA) and the American College of Radiology (ACR) help ensure that mammography is safe and diagnostic. COMPRESSION Compression is important for high quality mammographic imaging. If applied properly, compression should be slightly uncomfortable. Compression Helps: 1. Thin the breast for even x-ray exposure 2. Reduce radiation scattering by decreasing breast thickness 3. Reduce motion 4. Prevent tissue overlap.

Mammographic Views Two projections of views of each breast should be obtained for the Screening Mammogram. Additional Views may be added when abnormalities are found or an area needs further investigation. (Screening Mammogram then becomes a Diagnostic Mammogram).

Medio-Lateral Oblique (MLO) The Medio-Lateral Oblique view is the most valuable mammographic view. It allows imaging from high in the axilla, down to the inframammary fold, and back to the chest wall. The nipple should be imaged in profile in order to not be mistaken for a mass. The pectoralis muscle should be included in the view. Angulation of the mammography unit for the MLO view will vary between 30 and 60 degrees depending on the patient. The breast tissue is compressed from medial to lateral.

The MLO view estimates the location of a mass either superior or inferior to the nipple with slight variation due to the obliquity (angle).

Cranio-Caudal (CC) The Cranio-Caudal (CC) view is the next most valuable view. The mammography unit is adjusted to place the x-ray beam perpendicular to the floor. The nipple should also be seen in profile. The breast tissue is compressed from superior to inferior. Remember, marker placement will be towards the axilla. The CC view describes the location of a mass either medial or lateral to the nipple.

The LATERAL view is a true lateral view with the x-ray beam parallel to the floor. It can be performed as a mediolateral (ML) or lateromedial (LM) projection. This view most accurately demonstrates pathology location in the superior of inferior quadrants.

The LATERAL view

SPOT COMPRESSION Spot compression views with or without MAGNIFICATION are used to image small regions of the breast with greater compression. This may alleviate tissue overlap and obtain a close-up view to evaluate the margins and shape of a mass. A smaller compression paddle is used for the spot compression view. This allows maximum compression for high quality imaging in a specific area.

Spot Compression

The CLEAVAGE view (CV) The cleavage view (CV) is a view of the medial – on inner- portions of BOTH breasts. It is valuable when there is a lesion suspected in the most medial portion of the breast.

The CLEAVAGE view (CV)

Other mammographic views Axillary tail view – similar to the MLO, more focused on the Tail of Spence. Rolled views- attempts to displace the breast tissue to confirm a lesion Special implant views include the IMPLANT DISPLACED (ID) or EKLUND views.

Mammographic Examination The routine screening mammogram should be well understood and used as a road map for determining the location and appearance of abnormal structures.

Right/left breast – MLO views

Right Breast – CC view Fibroglandular tissue (White Areas)

Correlating Location Understanding the location of an abnormality detected on mammography is extremely important. It serves as a road map for identifying the lesion on all other imaging means including biopsy. Here are the RULES: ML view – above the nipple is the superior region of the breast. Below the nipple is inferior. You have no knowledge of medial or lateral. CC view – from nipple to marker is lateral. From nipple away from marker is medial. You have no knowledge of superior and inferior. (Marker is always in the Axilla). Put the 2 views together, and use the quadrant method or clock method to determine location.

If you only have information from the ML or MLO view and a breast lesion is identified above the nipple, the area of interest becomes the superior half of the breast. If you only have information from the CC view and a breast lesion is identified toward the marker, the area of interest becomes the lateral half of the breast.

Correlating location (continued) Mammography routinely uses a variety of views. A screening mammogram is make up of the MLO and CC views (requirement of MQSA). Due to a slight variation in the degree of obliquity of he MLO view (30 to 60 degrees), the location of a lesion on the MLO view can be tricky. This can cause the location of a lesion to be misjudged or give the appearance that a lesion has “moved”. Correlating the location of a lesion on a screening mammogram using the MLO and CC views is as follows:

Here are the rules: MLO view – Above the nipple is the superior region of the breast. Below the nipple is inferior. You have no knowledge of medal and lateral. Since this is not a true lateral view, however, lesions located in the medial portion of the breast will actually be located slightly higher. Lesions in the lateral portion of the breast will actually be located slightly lower. Remember MULD- medial up, lateral down. CC view- From nipple to marker is lateral. From nipple away from marker is medial. You have no knowledge of superior and inferior. (Marker is always in the axilla). Put the 2 views together, and use the Quadrant method or Clock method to determine location.

Let’s practice!

Mammographic Density Mammography creates an image because different tissues absorb different amounts of x-ray energy. There are three basic types of densities identified on mammography: Dark Gray to medium gray Light gray White

Mammographic Densities with Associated Tissue Types Fat Density (low absorption) Dark Gray to Medium Gray (Radiolucent) Fat Water Density (Medium absorption) Light Gray (Radiopaque) Fibroglandular tissue, cysts, tumors (benign and Malignant) Calcium Density (high absorption) While (radiopaque) Calcifications

Breast cyst

Benign fibroadenoma

Invasive carcinoma

Based on density alone, if may not be possible to distinguish normal from abnormal tissue, cysts from solid tumors, and benign from malignant tumors on mammography. Other diagnostic features must be considered for an accurate diagnosis.

Benign and Malignant Mammographic features The benign and malignant categories listed in this module are generalizations used for predictability and this course. Multiple features such as shape, margins, density, and the presence and type of calcifications, together are used to reach a diagnostic conclusion.

Shapes Round Oval – ellipsoid Lobulated – shaped with undulations Irregular- usually with angles and straight lines Spiculated – straight lines which rotate from the center of a tumor.

BENIGN MALIGNANT Round Oval Lobulated Irregular Spiculated The most common shape of breast cancer on mammography is IRREGULAR

Cartoons of Shapes

Round mass on a Mammogram Myofibroblastoma

Irregular mass on a mammogram

Margins Smooth – Also termed circumscribed Macro-Lobulated – gentle large lobulations Micro-Lobulated – Multiple small lobulations ( usually 2 mm) Ill-Defined – obscured or indistinct margins that are poorly defined (usually means tumor invasion into surrounding tissues). Angular – Irregular, jagged margins (highly sensitive for malignancy. Spiculated – straight lines which radiate from the center of a tumor (characteristic most specific for malignancy)

Mammogram with angular margined mass-spot compression

Benign Malignant Smooth Circumscribed Macrolobulated Micorlobulated Ill-defined Angular Spiculated

Mammogram mass with spiculated margins

Chart from Smooth to spiculated

Density The skinny – black is radiolucent / white is radiopaque The density of a lesion or structure seen on mammography provides the least predictive ability of determining benign vs. malignant characteristics. Density terms used in mammography include radiolucent and radiopaque based on the amount of x-ray energy absorbed by the breast tissue.

Fat density structures are radiolucent: Fatty cysts Lipomas- benign Mixed fat and water density structures: Lymph nodes Galactocele- benign Fibroadenolipoma – benign Water density structures are radiopaque Glandular tissue Connective tissue (stroma) Lactiferous Ducts Pectoralis Major muscle Cysts Hematoma Fibroadenoma – benign Phyllodes – benign or malignant Malignant tumors

Calcium Density structures are radiopaque Calcifications (both benign and malignant) Unfortunately, dense fibro-glandular tissue may hide tumors on mammography. Therefore, screening mammography for patients with dense breasts may be difficult

Mass of focal asymmetric density (FAD)

Density Normally, the density of the fibroglandular tissue of the breast will gradually decrease with advancing age. The is due to fatty replacement and involutional (progressional decline) changes following menopause. Less often, fibroglandular tissue density increases and may be noted in women lactating, taking hormone replacement Therapy (HRT) or those that experience weight loss. These changes in the breast can also be appreciated on mammography.

Dense breast of a 32 yof

Fatty breast of 68 yof

Before and after HRT

Mammography before (A) and during (B) lactation

Calcifications Mammography is the only imaging modality that can consistently identify calcifications in the breast. Sonography is not extremely helpful. Calcifications can occur in both benign and malignant breast disease. Statistically, calcifications are more commonly associated with benign processes. Approximately half of all breast cancers, however, contain calcifications. Several types of calcifications exist…

Typical Benign Calcifications Vascular – appear as calcified tubes associated with vessels. Large coarse – also known as Popcorn calcifications, usually larger than 1mm – commonly caused by a degenerating fibroadenoma. Rod-Shaped – calcium deposited within the ducts. Rim or Eggshell – may be seen as a crescent or rim shape or round with a lucent center (eggshell) – either represents calcium deposit in a cyst, milk or calcium cyst, sebaceous cyst, hemorrhagic cyst, or fat necrosis.

Vascular calcifications

Large coarse calcification

Rod shaped calcifications

Eggshell calcification

Suspicious Calcifications Punctate (microcalcifications) – very small (less than 0.5mm) pinpoint calcifications, associated with fibrocystic change, fibroadenoma, Sclerosing Adenosis or malignancy. Flake-Shaped – small, indistinct and fuzzy, tend to be malignant. Linear Branching – fine, interrupted, linear calcifications within the ducts (not solid rods), almost exclusively associated with malignancy.

Calcification patters Diffuse – scattered randomly, associated with benign lesions. Clustered microcalcifications- usually associated with fibroadenoma or malignant lesions. Segmental – suggest the calcifications follow a ductal system, associated malignancy. Regional- calcifications cover a segment or quadrant of the breast, associated wit malignancy.

Interrupted, linear micorcalcifications

Diffuse calcifications

Clustered microcalcifications

FIN