Which of the following methods is used for bone density measurement?

Photon Absorptiometry is a method specifically designed for bone density measurement. It operates based on the principle of measuring the absorption of photons as they pass through bone. This technique allows for precise determination of bone mass and density, which is critical in assessing a person's bone health and risk for osteoporosis and fractures.

This method utilizes a source of radiation, typically X-rays, to measure the degree to which these rays are absorbed by the bone in comparison to surrounding tissue. Because mineral content in bones absorbs X-rays at a different rate than soft tissues, this difference can be quantified to provide a clear assessment of bone density.

In contrast, while other options may involve imaging techniques, they are not primarily or specifically intended for measuring bone density. For instance, Conventional Radiography is more focused on providing images for diagnosis of various conditions rather than exclusively measuring bone density. Nuclear Magnetic Resonance, while it provides valuable information about tissue composition, does not specifically target bone density in the manner that photon absorptiometry does. Photoelectric Absorptiometry, while related to measuring density, is not as widely recognized or used in practice for this specific purpose as photon absorptiometry is.