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Found. of radiology
foundations of radiology
Term | Definition |
---|---|
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. |
Denstiy | 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 | Flexible arm that is attached to the x-ray tubehead |
Genetic effects | Effects of radiation that are passed on to 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. |
Kilovoltage | 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 | 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 onto 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. |
Automatic processor | Machine that automates all film processing steps. |
Beam alignment device | Assists in the positioning of the position indicator device (PID). |
Bitewing | Image view that shows the crowns of both arches on one film. |
Calcium tungstate | Common type of phosphor. |
Cassette | Contains extraoral films during exposure. |
Cephalometric film | Shows the bony and soft tissue areas of the facial profile. |
Charge-coupled device (CCD) | A solid-state image sensor used in intraoral digital imaging. |
Digital image | Electronic signals captured by sensors and displayed on computer monitors. |
Digitize | Scanning of traditional film-based radiographs into a digital image. |
Duplicating film | Film designed for use in film duplicating machines. |
Emulsion | A coating on the x-ray film that contains energy sensitive crystals. |
Extraoral film | Film designed for use in cassettes. |
Film speed | The sensitivity of the emulsion on the film to radiation. |
Intensifying screen | The part inside an extraoral cassette that converts x-ray energy into visible light, which in turn exposes screen film. |
Intraoral film | Film designed for placement in the patient’s mouth. |
Label side | Colored side of the film that faces the tongue. |
Latent image | The invisible image on the x-ray film after exposure but before processing. |
Occlusal | Radiographic view that shows large areas of the maxilla or mandible. |
Panoramic film | Used in cassettes to provide a wide view of both the upper and lower jaws. |
Periapical | Radiographic view that shows the crown, root tip, and surrounding structures. |
Phosphor storage plate (PSP) | Reusable film-sized plates coated with phosphor as the image receptor. |
Positioning instruments | Intraoral devices used to position and hold the film, sensor, or PSP |
Processing | A series of steps that change exposed film into a radiograph. Steps include developing, rinsing, fixing, washing, and drying. |
Teledentistry | Process of using electronic transfer of images and other information for consultation and/or insurance purposes in dentistry. |
Tube side | Solid white side of the film packet that faces the x-ray tube. |