X-ray Imaging

X-ray imaging is a common diagnostic imaging technique. It uses X-rays - which are high-energy electromagnetic radiations that pass through the human body, to produce a negative-type image of internal body structures.

The resulting image is called a radiograph - shadows of the rays on a digital or film medium. Radiation dose and exposure time are monitored to avoid radiation induced  sickness.

X-rays passing through the body are differentially absorbed depending on the tissue density. Dense structures like bones appear white, as the rays cannot pass through them; therefore, they are radiopaque. Soft tissues like muscles, and organs like the liver and stomach are less dense; since they allow more rays to pass through, they appear in shades of gray. Air that has the lowest radiopacity appears black.

X-ray imaging can detect bone fractures, dental problems, tumors, and certain infections.

However, this technique allows only two-dimensional image capture. Further, it poorly differentiates structures with the same densities, these require better imaging techniques like computed tomography or MRI.