2026 ARRT Mammography Study Guide
Practice Questions & Answer
Explanations Breast Imaging • Patient
Positioning • Radiation Safety
Procedures • Clinical Preparation
Review
Section 1: Breast Anatomy & Physiology (Questions 1–20)
1. The breast is located between which two layers of the chest wall?
• A) Pectoralis major and pectoralis minor
• B) Superficial and deep layers of the pectoral fascia
• C) Subcutaneous fat and retromammary fat
• D) Skin and rib cage
Correct Answer: B) Superficial and deep layers of the pectoral fascia
Rationale: The breast lies between the superficial and deep layers of the
pectoral fascia. The deep layer covers the pectoralis major muscle, and the
superficial layer lies just beneath the skin. This anatomy is important for
understanding implant placement and surgical planes.
2. What is the functional unit of the breast responsible for milk production?
• A) Lactiferous sinus
• B) Alveolus
, • C) Lactiferous duct
• D) Nipple
Correct Answer: B) Alveolus
Rationale: The alveolus (plural: alveoli) is the milk-producing glandular
structure within the breast lobule. Milk travels from alveoli → ductules →
lactiferous ducts → lactiferous sinus → nipple.
3. How many lobes are typically found in a mature female breast?
• A) 5–10
• B) 10–15
• C) 15–20
• D) 20–25
Correct Answer: C) 15–20
Rationale: The mature female breast typically contains 15–20 lobes, each
drained by its own lactiferous duct. This lobar architecture is relevant when
evaluating focal breast findings on mammography.
4. Cooper's ligaments are responsible for:
• A) Milk ejection
• B) Supporting the breast structure
• C) Blood supply to the nipple
• D) Lymphatic drainage
Correct Answer: B) Supporting the breast structure
, Rationale: Cooper's ligaments (suspensory ligaments) extend from the deep
pectoral fascia to the skin and provide structural support to the breast. Their
involvement by tumor can cause skin retraction or nipple inversion.
5. The terminal ductal lobular unit (TDLU) is significant because:
• A) It is where most breast cancers originate
• B) It produces oxytocin
• C) It is the site of lymphatic filtration
• D) It stores milk between feedings
Correct Answer: A) It is where most breast cancers originate
Rationale: The TDLU is the functional unit of the breast and the site of origin
for the majority of breast carcinomas, including ductal carcinoma in situ (DCIS)
and invasive ductal carcinoma.
6. Which blood vessels primarily supply the breast?
• A) Internal mammary and lateral thoracic arteries
• B) Subclavian and axillary veins only
• C) Intercostal arteries only
• D) Thoracoacromial and subscapular arteries
Correct Answer: A) Internal mammary and lateral thoracic arteries
Rationale: The breast receives blood supply primarily from the internal
mammary (thoracic) artery and the lateral thoracic artery, with contributions from
intercostal perforating branches.
7. The axillary lymph nodes are important in breast imaging because:
, • A) They produce milk
• B) They are the primary drainage site for breast lymph
• C) They regulate breast hormones
• D) They are always removed during biopsy
Correct Answer: B) They are the primary drainage site for breast lymph
Rationale: Approximately 75% of breast lymph drains to the axillary lymph
nodes. Axillary node status is a critical prognostic factor in breast cancer and is
evaluated with imaging and sometimes sentinel node biopsy.
8. The nipple-areolar complex contains which type of muscle?
• A) Cardiac muscle
• B) Smooth muscle
• C) Skeletal muscle
• D) No muscle tissue
Correct Answer: B) Smooth muscle
Rationale: The nipple contains smooth muscle fibers that contract to eject
milk (the let-down reflex). This is under hormonal control, not voluntary control.
9. Which hormone is primarily responsible for lobular development in the
breast?
• A) Estrogen
• B) Progesterone
• C) Prolactin
• D) Oxytocin
Practice Questions & Answer
Explanations Breast Imaging • Patient
Positioning • Radiation Safety
Procedures • Clinical Preparation
Review
Section 1: Breast Anatomy & Physiology (Questions 1–20)
1. The breast is located between which two layers of the chest wall?
• A) Pectoralis major and pectoralis minor
• B) Superficial and deep layers of the pectoral fascia
• C) Subcutaneous fat and retromammary fat
• D) Skin and rib cage
Correct Answer: B) Superficial and deep layers of the pectoral fascia
Rationale: The breast lies between the superficial and deep layers of the
pectoral fascia. The deep layer covers the pectoralis major muscle, and the
superficial layer lies just beneath the skin. This anatomy is important for
understanding implant placement and surgical planes.
2. What is the functional unit of the breast responsible for milk production?
• A) Lactiferous sinus
• B) Alveolus
, • C) Lactiferous duct
• D) Nipple
Correct Answer: B) Alveolus
Rationale: The alveolus (plural: alveoli) is the milk-producing glandular
structure within the breast lobule. Milk travels from alveoli → ductules →
lactiferous ducts → lactiferous sinus → nipple.
3. How many lobes are typically found in a mature female breast?
• A) 5–10
• B) 10–15
• C) 15–20
• D) 20–25
Correct Answer: C) 15–20
Rationale: The mature female breast typically contains 15–20 lobes, each
drained by its own lactiferous duct. This lobar architecture is relevant when
evaluating focal breast findings on mammography.
4. Cooper's ligaments are responsible for:
• A) Milk ejection
• B) Supporting the breast structure
• C) Blood supply to the nipple
• D) Lymphatic drainage
Correct Answer: B) Supporting the breast structure
, Rationale: Cooper's ligaments (suspensory ligaments) extend from the deep
pectoral fascia to the skin and provide structural support to the breast. Their
involvement by tumor can cause skin retraction or nipple inversion.
5. The terminal ductal lobular unit (TDLU) is significant because:
• A) It is where most breast cancers originate
• B) It produces oxytocin
• C) It is the site of lymphatic filtration
• D) It stores milk between feedings
Correct Answer: A) It is where most breast cancers originate
Rationale: The TDLU is the functional unit of the breast and the site of origin
for the majority of breast carcinomas, including ductal carcinoma in situ (DCIS)
and invasive ductal carcinoma.
6. Which blood vessels primarily supply the breast?
• A) Internal mammary and lateral thoracic arteries
• B) Subclavian and axillary veins only
• C) Intercostal arteries only
• D) Thoracoacromial and subscapular arteries
Correct Answer: A) Internal mammary and lateral thoracic arteries
Rationale: The breast receives blood supply primarily from the internal
mammary (thoracic) artery and the lateral thoracic artery, with contributions from
intercostal perforating branches.
7. The axillary lymph nodes are important in breast imaging because:
, • A) They produce milk
• B) They are the primary drainage site for breast lymph
• C) They regulate breast hormones
• D) They are always removed during biopsy
Correct Answer: B) They are the primary drainage site for breast lymph
Rationale: Approximately 75% of breast lymph drains to the axillary lymph
nodes. Axillary node status is a critical prognostic factor in breast cancer and is
evaluated with imaging and sometimes sentinel node biopsy.
8. The nipple-areolar complex contains which type of muscle?
• A) Cardiac muscle
• B) Smooth muscle
• C) Skeletal muscle
• D) No muscle tissue
Correct Answer: B) Smooth muscle
Rationale: The nipple contains smooth muscle fibers that contract to eject
milk (the let-down reflex). This is under hormonal control, not voluntary control.
9. Which hormone is primarily responsible for lobular development in the
breast?
• A) Estrogen
• B) Progesterone
• C) Prolactin
• D) Oxytocin
