Tutorial - DEXA Scans Flashcards
Bone resorption/turnover is constant and highest in trabecular bone. TRUE OR FALSE.
True
What is bone made of?
Mineral (CA) and matrix (pro and connective tissue).
What percentage of degradation is needed for an X-ray to show osteoporosis?
30%
What does the 2C, 3C and 4C model assess.
2C = fat + FFM
3C = Water, fat + FFM
4C = Bone, water, fat + FFM
Does the spine have a high proportion of trabecular or cortical bone?
Trabecular
What degree of internal rotation should the hip be rotated to be assessed?
30 degrees
Should you test the dominant side of the wrist for a DEXA scan?
Non-dominant
Beyond age 50 it is typical to experience a ….% loss of bone per year
1-5%
Bone mineral content =
bone mineral density x area
Does the radius have a small proportion of trabecular bone
Yes (33%)
What amount of radiation is produced from a DEXA scan?
1-10 microsieverts
Compared to:
Background 5-8/day
Mammogram 450
Lumbar spine and thoracic spine 1800
Ultrasound 0
Transatlantic flight 50-100
Peak BMD
16-23 years
Effects of estrogen medication
Anti-resorption
Spine BMD increase 4-6% in 3 years
Effects of calcitonin medication
Anti-resorption
Spine BMD increase 1% in 5 years
Effects of Bisphosphonates
Anti-resorption medication (oral or IV)
Spine BMD >5% in 3 years
