Category: D

A technique used in ultrasound imaging to monitor the behavior of a moving structure such as flowing blood or a beating heart. The frequency of ultrasonic waves reflected from a moving surface is slightly different from that of the incident waves. The detected frequency shift yields information about the moving structure. Fetal heart detectors work…

A change in the observed frequency of a wave that occurs when the source and the observer are moving relative to each other. The variation of the apparent frequency of waves, such as sound waves, with change in distance between the source and the receiver. The frequency seems to increase as the distance decreases and…

Any method of x-ray image formation that uses a computer to store and manipulate data. Radiography using computerized acquisition of data for imaging instead of conventional or analog film and intensifying screen imaging.  

Medical imaging using external sources of radiation.  

The relationship between dose at any depth from a beam of radiation compared with the dose at the entrance from that beam is a measure of the depth dose characteristics. The actual amount of radiation exposure at a specific point below the surface of the body. The depth dose corresponds to the radiation dosage administered…

The element that results from the radioactive decay of a parent element. An example is technetium-99 which is the daughter element created by the decay of an atom of molybdenum-99.  

When a child has not developed the ability to walk within the normal age range. Although each child has his or her own rate of development, babies normally become able to bear some weight on their legs by 7 months. The inability to walk by the age of 18 months is generally considered delayed motor…

An injury in which the ends of the bones that form the shoulder joint are forced from their normal positions. A dislocated shoulder is usually caused by a blow, a fall, or other trauma. An injured shoulder that is visibly out of position, misshapen, swollen, difficult to move, and intensely painful probably has been dislocated…

Replacing a tooth torn from its socket in an injury to the mouth. If the tooth is properly preserved until a dentist can be seen, the tooth can often be saved by being reimplanted into the gum by the dentist. It is recommended that the tooth be kept in milk. If milk is not available,…

The displacement of the bones of the jaw’s temporomandibular joint, which causes soft-tissue damage to the joint capsule and to the ligaments. Muscles connected to the joint may be strained, resulting in painful muscle spasms in the area of the jaw. When the jaw is dislocated, it is often impossible to close the mouth. The…