Medical Imaging Flashcards
What does HR-pQCT stand for?
High resolution peripheral quantitative computed tomography
Body composition by DXA (dual-energy x ray absorptiometry) the new gold standard
A 3 component model measuring
Fat
Lean (bone mineral free and fat free)
Bone mineral
What does BIA stand for?
Bioelectric impedance analysis
What does BIA measure?
Estimates of total body water (TBW) and fat free mass (FFM
How does BIA work?
The proportion of body fat can be calculated as the electrical current flows more easily through tissue that is comprised of mostly water (muscle, organs, blood etc) than it does through fat
How does pQCT work?
Provides a three dimensional assessment of bone density and architecture
Limited to radius and tibia
How does DXA work?
An x-ray machine sends out two rays with different energies. As the rays pass through the patient, some are stopped by the bone mineral or by other tissues in the body such as fat, water or protein. An x-ray detector above the patient can tell how much energy got through, & this info is sent to a computer which analyzes it & forms an image
Body mass index (BMI)
How do you calculate this?
Weight (kg)/height (m squared)
Where do i fit when calculating BMI?
Underweight < 18.5 Normal 18.5 - 24.9 Overweight 25.0 - 29.9 Obesity one 30.0 - 34.9 Obesity two > 34.9
What does WHR stand for?
Waist/ hip ratio
Most common measure of fat distribution is the waist girth to hip girth ration (WHR)
Low WHR= low risk of cardiovascular disease, hypertension, stroke, diabetes
True
What is the high risk abdominal girth measurement?
Males > 100cm
Females > 90cm
Question: if increasing fatness is a health risk, why are women, who generally have a higher % fat value than men, at a lower risk than men for obesity-related illnesses?
Answer: it is not how much, but where
Fat patterning Male pattern=android (apple shaped) Characterised by abdominal fat Female pattern=gynoid (pear shaped) Characterised by hip & gluteal fat
