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Radiology
Foundations of Radiology
| Term | Definition |
|---|---|
| ALARA concept | ALARA concept Concept of radiation protection that states that all exposures should be kept “as low as reasonably achievable.” |
| Anode | The positive electrode in the x-ray tube |
| Atom | The basic unit of matter |
| Bremsstrahlung radiation | “Braking radiation.” The sudden deceleration of electrons as they interact with highly positively charged nuclei |
| Cathode | The negative electrode in the x-ray tube |
| Central ray | X-rays at the center of the beam |
| Contrast | Differences in degrees of blackness on an image |
| Control panel | The portion of the x-ray unit that contains the master switch, the indicator light, the selector buttons, and the exposure button |
| Density | The overall darkness or blackness of an image |
| Dental radiography | The process of recording images of the teeth and adjacent structures by exposure to x-radiation |
| Digital imaging | A filmless method of capturing an image and displaying it by using an image receptor, an electronic signal, and a computer to process and store the image |
| Distortion | Change in the size of an image caused by incorrect vertical angulation |
| Dose (of radiation) | The amount of energy absorbed by tissues |
| Dosimeter | A device used to detect and measure an accumulated dosage of radiation. |
| Electron | A negatively charged particle in the atom. |
| Energy | The ability to do work |
| Extension arm | Extension arm Flexible arm that is attached to the x-ray tubehead |
| Genetic effects | Effects of radiation that are passed onto future generations through genetic cells |
| Image | Film-based or digitally produced recordings of anatomic structures. |
| Image receptor | A recording medium for an image, normally film, phosphor storage plate (PSP), or a digital sensor |
| Intensity | The total energy of the x-ray beam. |
| Ion | An electrically charged particle. |
| Ionization | Process by which electrons are removed from atoms, causing the harmful effects of radiation in humans. |
| Ionizing radiation | Radiation that produces ionization, resulting in harmful effects |
| Kilovoltage peak (kVp) | Highest voltage of x-ray tube used during an exposure. |
| Latent period | Time between exposure to ionizing radiation and appearance of symptoms |
| Lead apron | Device used to protect the reproductive and blood-forming tissues from scatter radiation. |
| Magnification | The proportional enlargement of an image. |
| Master switch, indicator light, selector buttons, exposure button | Components of control panel. |
| Matter | Anything that occupies space and has form or shape |
| Milliampere (mA) | One one-thousandth (1/1000) of an ampere; a unit of measurement used to describe the intensity of an electrical current. |
| Penumbra | The blurred or indistinct area that surrounds an image. |
| Personal radiation monitoring badge | A device that measures exposure of personnel to ionizing radiation by measuring the intensity of visible light emitted from a crystal in the detector when heated. The intensity of light emitted is dependent upon the radiation exposure |
| Photon | A minute bundle of pure energy that has no weight or mass |
| Primary beam | The most penetrating beam produced at the target of the anode. |
| Primary radiation | Same as primary beam |
| Quality (of x-ray beam | The mean energy or penetrating ability of the x-ray beam. |
| Quantity (of x-ray beam) | The number of x-rays produced in the dental unit; the quantity of x-rays produced is controlled by milliamperage. |
| Radiation | Forms of waves of energy emission through space or material. |
| Radiograph | Image produced on photosensitive film by exposing the film to radiation and then processing it. |
| Radiology | The science or study of radiation as used in medicine. |
| Scatter radiation | A form of secondary radiation that occurs when an x-ray beam has been deflected from its path by interaction with matter |
| Secondary radiation | X-radiation that is created when the primary beam interacts with matter |
| Sensor | A solid-state image receptor that contains a silicon chip with an electric circuit. |
| Sharpness | A measure of how well an image reproduces the fine details or outline of an object. |
| Somatic effects | Effects of radiation that cause illness and are responsible for poor health (such as cancer, leukemia, and cataracts) but are not passed on to offspring |
| Thyroid collar | A flexible lead shield that is placed securely around the neck. |
| Tubehead | The part of the x-ray unit that contains the x-ray tube, the high-voltage and low-voltage transformers, and insulating oil. |
| Tungsten target | A focal spot in the anode. |
| X-radiation | High-energy ionizing electromagnetic radiation. |