Overview of Measurement Techniques

Whole Body Gamma Counter (WBC) - 40K
This extremely sensitive device detects gamma rays emitted by the human body. Most of the natural signal coming from the human body is from an isotope of potassium (K).

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Whole Body Counter

Neutron Activation In Vivo Neutron Activation Analysis (IVNAA)
This technique uses neutrons to stimulate production of
gammas from certain elements. The gammas are subsequently measured by the whole body counter.
Dual-Energy X-ray Absorptiometry (DXA)
A precisely controlled x-ray beam scans an entire body for
determination of bone mineral content, body fat, and lean
tissue mass. Localized scanning focuses on spine, hip, and
other bone sites.
DXA Scanning
BIA Fat Assessment Bioelectrical Impedance Analysis (BIA)
The resistance to an applied electric current flowing through the body is related to the volumes of conductive tissues that the current passes through. This measurement can estimate water and fat ratios.

Body composition is estimated using body density (mass/volume). Body mass is combined with a measurement of body volume obtained using an air-displacement plethysmograph called a BodPod®. Estimates of fat and fat-free mass are generated.

BodPod density measurement


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