Abstract: A technique for determining percent body fat using neutron inelastic scattering is disclosed. It relies on a correlation between a carbon-oxygen ratio in the body and the percent body fat with corrections made for a level of patient hydration in the lean tissue. The animal body is irradiated with neutrons having sufficient energy to inelastically scatter off carbon and oxygen. The resulting gamma rays are detected and counted, and the level of hydration is measured. The ratio of the detected gamma rays and hydration are then related to a proportion of fat in the animal body. This technique provides accuracy approaching that achieved with hydrodensitometry with only small radiation doses between 5 and 20 millirem, but without any requirements for immersion.

Abstract: A technique for determining percent body fat using neutron inelastic scattering is disclosed. It relies on a correlation between a carbon-oxygen ratio in the body and the percent body fat with corrections made for a level of patient hydration in the lean tissue. The animal body is irradiated with neutrons having sufficient energy to inelastically scatter off carbon and oxygen. The resulting gamma rays are detected and counted, and the level of hydration is measured. The ratio of the detected gamma rays and hydration are then related to a proportion of fat in the animal body. This technique provides accuracy approaching that achieved with hydrodensitometry with only small radiation doses between 5 and 20 millirem, but without any requirements for immersion.

Abstract: A body composition measurement device and method, particularly for soft tissue, are useful to determine levels of hydration or percent body fat, for example. It relies on the X-ray absorption analysis for a single energy or two or more energies. If only a single energy is used, then the length of the x-ray path through the soft tissue of the patient is measured. In one embodiment, body composition measurement device comprises measurement calipers, with the x-ray source and detector located on each caliper arm. The calipers determine the path length. As such, a controller either in the calipers or external to it can combine the information from the calipers and the detector to provide an indication of the body's soft tissue composition along the path.

Abstract: A method for in vivo NMR imaging of the blood vessels and organs of a patient characterized by using a dark dye-like imaging substance consisting essentially of a stable, high-purity concentration of D.sub.2 O in a solution with water.