Page 1 of 220
FINAL EXAM TESTBANK 2026 QUESTIONS
WITH 100% VERIFIED ANSWERS. PDF
1. Absorptiometry (DXA) uses two distinct X-ray energy levels
primarily to:
Answer: Separate bone mineral density from soft tissue.
Rationale: DXA uses two X-ray energies (typically 40 keV and
70–100 keV). Soft tissue attenuates the two energies differently,
allowing calculation of bone mineral content independent of soft
tissue thickness. This dual-energy subtraction technique provides
accurate areal bone mineral density (g/cm²).
2. What is the primary clinical application of A?
Answer: Diagnosis of osteoporosis and assessment of fracture
risk.
Rationale: DXA is the gold standard for measuring bone mineral
density (BMD). T-scores from DXA are used to diagnose
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osteoporosis (T ≤ –2.5), osteopenia (–2.5 < T < –1.0), and
normal bone density (T ≥ –1.0) according to WHO criteria.
3. Which anatomical sites are recommended for standard DA
measurement by the International Society for Clinical
Densitometry (ISCD)?
Answer: Lumbar spine (L1–L4) and proximal femur (total hip
and femoral neck).
Rationale: The ISCD recommends measuring both the spine and
hip for initial diagnosis. Forearm (33% radius) is used when spine
or hip cannot be measured or interpreted (e.g., severe
degenerative changes, hyperparathyroidism, very obese
patients).
4. The T-score compares a patient’s BMD to:
Answer: The mean BMD of a young healthy adult reference
population at peak bone mass (age 20–29 years, same sex and
ethnicity).
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Rationale: T-scores are calculated as (patient BMD – young adult
mean BMD) / young adult standard deviation. A T-score ≤ –2.5
defines osteoporosis.
5. The Z-score compares a patient’s BMD to:
Answer: Age-, sex-, and ethnicity-matched individuals.
Rationale: Z-scores are used in children, premenopausal women,
and men under 50. A Z-score < –2.0 is considered “below the
expected range for age” and may indicate secondary causes of
bone loss.
6. The ISCD recommends using the _____ for diagnostic
classification in postmenopausal women and men age 50 and
older.
Answer: T-score.
Rationale: The WHO diagnostic criteria based on T-scores apply
to these populations. Z-scores are not used for diagnosis in this
group.
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7. Which of the following is a limitation of DXA?
Answer: It measures areal BMD (g/cm²) not volumetric density,
and results can be artifactually elevated by degenerative
changes, aortic calcification, or vertebral fractures.
Rationale: DXA is a two-dimensional projection technique. It
cannot distinguish cortical from trabecular bone and is affected
by artifacts such as osteophytes, sclerosis, or contrast material.
8. The DXA scan acquisition mode (e.g., fast, standard, or
slow) should be selected based on:
Answer: Patient size and thickness.
Rationale: Larger patients require higher energy or longer scan
times to achieve adequate image quality. Using an
inappropriate mode can increase radiation exposure or reduce
accuracy.
9. Which of the following best describes the radiation effective
dose from a typical DXA scan (spine and hip)?
FINAL EXAM TESTBANK 2026 QUESTIONS
WITH 100% VERIFIED ANSWERS. PDF
1. Absorptiometry (DXA) uses two distinct X-ray energy levels
primarily to:
Answer: Separate bone mineral density from soft tissue.
Rationale: DXA uses two X-ray energies (typically 40 keV and
70–100 keV). Soft tissue attenuates the two energies differently,
allowing calculation of bone mineral content independent of soft
tissue thickness. This dual-energy subtraction technique provides
accurate areal bone mineral density (g/cm²).
2. What is the primary clinical application of A?
Answer: Diagnosis of osteoporosis and assessment of fracture
risk.
Rationale: DXA is the gold standard for measuring bone mineral
density (BMD). T-scores from DXA are used to diagnose
,Page 2 of 220
osteoporosis (T ≤ –2.5), osteopenia (–2.5 < T < –1.0), and
normal bone density (T ≥ –1.0) according to WHO criteria.
3. Which anatomical sites are recommended for standard DA
measurement by the International Society for Clinical
Densitometry (ISCD)?
Answer: Lumbar spine (L1–L4) and proximal femur (total hip
and femoral neck).
Rationale: The ISCD recommends measuring both the spine and
hip for initial diagnosis. Forearm (33% radius) is used when spine
or hip cannot be measured or interpreted (e.g., severe
degenerative changes, hyperparathyroidism, very obese
patients).
4. The T-score compares a patient’s BMD to:
Answer: The mean BMD of a young healthy adult reference
population at peak bone mass (age 20–29 years, same sex and
ethnicity).
,Page 3 of 220
Rationale: T-scores are calculated as (patient BMD – young adult
mean BMD) / young adult standard deviation. A T-score ≤ –2.5
defines osteoporosis.
5. The Z-score compares a patient’s BMD to:
Answer: Age-, sex-, and ethnicity-matched individuals.
Rationale: Z-scores are used in children, premenopausal women,
and men under 50. A Z-score < –2.0 is considered “below the
expected range for age” and may indicate secondary causes of
bone loss.
6. The ISCD recommends using the _____ for diagnostic
classification in postmenopausal women and men age 50 and
older.
Answer: T-score.
Rationale: The WHO diagnostic criteria based on T-scores apply
to these populations. Z-scores are not used for diagnosis in this
group.
, Page 4 of 220
7. Which of the following is a limitation of DXA?
Answer: It measures areal BMD (g/cm²) not volumetric density,
and results can be artifactually elevated by degenerative
changes, aortic calcification, or vertebral fractures.
Rationale: DXA is a two-dimensional projection technique. It
cannot distinguish cortical from trabecular bone and is affected
by artifacts such as osteophytes, sclerosis, or contrast material.
8. The DXA scan acquisition mode (e.g., fast, standard, or
slow) should be selected based on:
Answer: Patient size and thickness.
Rationale: Larger patients require higher energy or longer scan
times to achieve adequate image quality. Using an
inappropriate mode can increase radiation exposure or reduce
accuracy.
9. Which of the following best describes the radiation effective
dose from a typical DXA scan (spine and hip)?
