Hi Res (Breast) Flashcards
What muscles do the breast muscles lie over?
-pectoral
What are the breasts attached by?
-fascia (CT)
What are the breasts made of?
- milk producing mammary glands
- adipose tissue (fat)
Which ligament supports the breasts?
-suspensory ligament of cooper
What are the breast lobes separated by?
-septa (walls) of CT
What are the CT lobules embedded?
-in the pouches of milk secreting cells (alveoli)
How are the alveoli arranged?
-grapelike clusters around the tiny ductule
Where is the myoepithelial cell and what does it do?
- outside of the alveolus
- squeezes milk into the secretory duct
Lactiferous
-milk carrying
Where do the main lactiferous ducts converge toward?
-the nipple (enlarge into sm lactiferous sinuses before the nipple)
What forms the 15 to 20 lactiferous ducts of each lobe?
-ductules
What is the main function of the breasts?
-lactation
Lactiferous Sinuses
- positioned to be squeezed by the sucking motion of a baby
- pumping chambers that move milk out of breast
Border of Nipples
-areola
What does the areola contain?
- numerous sebaceous glands (Montgomery’s tubercles)
- sm nodules under the skin
Sebum
- produced by these areolar glands
- helps reduce irritating dryness of areolar skin while nursing
What do the areola secrete to enhance the mother infant bond?
-pheromones
What controls breast development of breasts during puberty?
-estrogen and progesterone (ovarian hormones)
What does estrogen stimulate?
-growth of ducts of mammary glands
What does progesterone stimulate?
-development of secreting cells (alveoli)
What is breast size determined by?
-fat around glandular tissue more than the tissue itself
Is breast size related to the amount of milk produced?
No.
What cuts off a major source of estrogen after delivery?
-shedding of placenta
What stimulates the anterior pituitary to secrete prolactin?
-rapid drop in blood concentration of estrogen after the placenta is shed
What stimulates the anterior pituitary to secrete prolactin and the posterior pituitary to secrete oxytocin?
-sucking movement of nursing baby
What stimulates lactation?
- prolactin
- stimulates alveoli of mammary glands to secrete milk
When does milk secretion start?
-3 or 4 days after delivery
What is the thin, yellow milk secretion (3-4 days after delivery) called?
-colostrum
What does oxytocin stimulate?
-myoepithelial cells int he alveoli to eject milk
Arterial Supply
- thoracic branches of the axillary arteries
- internal mammary and intercostal arteries
Venous Drainage
- anastomotic circle around the base of nipple
- branches carry venous blood to the circumference
- end in axillary and mammary veins
Lymph Drainage
- superficial axillary vessels and nodes
- internal mammary
- nodes if the superficial route is obstructed
How do cancer cells from malignant breast tumors often spread to other areas of the body?
-through lymphatics
Nerve Supply
- branches from T4, 5 and 6 (sympathetic fibres)
- numerous somatic sensory nerve endings (especially around nipple)
Involutional Breast Change
- normal
- occurs when women age (25 to 45)
- number of lobules in breast decreases
- CT is replaced with fibrotic collagen
- results in breast sagging
Polythelia
- accessory nipple
- most common congenital breast anomaly
Polymastia
- accessory breast
- in axilla
Amastia
-failure of breast tissue to develop
Athelia
-absence of nipple
Amazia
-absence of functional breast tissue beneath areola (nipple)
Poland Syndrome
-underdevelopment/absence of breast, nipple and chest muscles
Inverted Nipple
- congenital anomaly
- if not congenital, it is due to cancer
Micromastia
- anomaly
- abnormal smallness of the breast
Macromastia
- anomaly
- excessive size of the breast
Skin
- highly reflective band along surface of the breast
- 2 to 3mm thick
- bright, linear
- @ top of image
Subcutaneous Fat
- lies beneath the skin and breast parenchyma (mammary zone)
- quantity of fat varies
- homogenous
Cooper’s Lig.
- tent like
- arise from breast parenchyma
- echogenic
- extend radial from deep fascial planes to the skin
Parenchyma
- beneath subcutaneous fat
- mixed echogenicity
4 Patterns:
- fibrous
- premenstrual
- postmenstrual
- pregnant
Retromammary Fat
- posterior to parenchyma
- forms a layer between the deep fascia plane and pectoralis muscle
Pectoralis Muscle
- anterior to ribs
- imaged in direction of fibres
- appear parallel to skin, above the ribs
Ribs
- acoustic shadowing
- hypoechoic
Pleura
- linear echogenic line
- deep to rib
- moves with respiration
Nipple
-dense CT or CT of duct may cause shadowing
Tail of Spence
- aka axillary tail
- portion that extends to axillary regions
Lymph Node
- solid nodule
- oval
- echogenic, fatty hilum
Ducts
- tubular, branching structures
- converge sub areolar
What does breast density refer to?
-amount of fibroglandular tissue to fat tissue
High Breast Density
-greater amount of breast and CT than fat
Low Breast Density
-greater amount of fat compared to breast and CT
SCF
-subcutaneous fat
CL
-coopers lig.
FGT
-fibroglandular tissue
RMF
-retromammary fat
PM
-pectoralis muscle
Sono Appearance of Moral Lactating Breast Tissue
- prominent fluid filled ducts
- echogenic epithelial lining
Equipment and Technique
- high frequency transducer (8 to 15 MHz)
- wide footprint
- low frequency for large breasts, inflammation or axilla
- stand off pad for nipple, superficial/skin lesions
- low PRF colour and spectral doppler for vascular regions
- gain/TGC: 70% gain
- mammary fat should be medium grey from overlying fascia to retromammary space
Patient History
- family history
- age
- previous mammograms
- parity
- masses
- gravida
- scars
- aborta
- skin changes
- medications (hormones)
- nipple discharge
- breast surgeries
Patient Position
- supine
- roll patient to spread breast evenly
- raise ipsilateral arm over patient head
- if patient can only identify lump while standing, then scan standing
