A bitewing radiograph is an intraoral device that demonstrates the crowns, necks and coronal thirds of the roots of both upper and lower teeth. The imaged person bites upon a tab or wing projecting from the center of the image-receptor packet.

See also Bisecting Angle Technique.

A cathode is an electrode through which electric current flows out of a polarized electrical device. X-rays are produced by bombarding a target (the cathode), which is usually made of tungsten.

A clinical trial is a controlled study involving human subjects, designed to evaluate prospectively the safety and effectiveness of new drugs or devices or of behavioral interventions.

See also Adverse Reaction and Safety of Contrast Agents.

The (spot) compression of for example breast tissue, allows for greater reduction in thickness of the area of interest and improved separation of breast tissues by the use of a small compression device.
Compression can be also a software or hardware process that shrinks images to lessen the storage space. Compression is generally accomplished by removing the bits that define redundant like data blank spaces, and replacing them with a smaller symbolic code that represents the removed or redundant bits.

Another term for detector, by analogy to broadcast radio receivers. Other terms used for devices of this type include modulators, phase sensitive detector and mixers.