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Core Radiography
Terminology
Definition | Term |
---|---|
A skill set within the radiological sciences in which individuals operate radiation-producing equipment in order to image selected anatomical sites for diagnostic purposes in a variety of medical settings. | Limited Radiography |
Formal educational programs, which are usually short-term and specific, designed to promote knowledge, skills and professional attitudes. | Continuing Education |
The world's largest and oldest membership association for medical imaging technologists and radiation therapists-provides members with educational opportunities, promotes radiologic technology as a career, and monitors state and federal legislation that a | American Society of Radiologic Technologists (ASRT) |
A person who is credentialed and/or has sufficient education as defined by state or national credentialing boards to operate radiation-producing equipment in order to obtain diagnostic images of a selected anatomical site. | Limited X-Ray Machine Operators |
The largest certifying body in the radiological profession; promotes high standards of patient care by recognizing qualified individuals in medical imaging, interventional procedures, and radiation therapy. | American Registry of Radiologic Technologists (ARRT) |
The profession's largest programmatic accrediting agency; reviews a program's admission policy, curriculum, academic practices, and faculty qualifications. | Joint Review Committee on Education in Radiologic Technology (JRCERT) |
An individual graduated form a nationally accredited education program in the radiologic sciences; registered with the ARRT or an equivalent national organization or holds a full-state license. | Radiologic Technologist |
An individual other than a radiologic technologist who performs diagnostic x-ray procedures on selected anatomical sites. | Limited Radiographer |
A law enacted in 1981 in response to growing concern and awareness about potential long-term effects from radiation exposure; gave Congress the power to limit unnecessary or excessive radiation exposure for consumers and patients. | Consumer-Patient Radiation Health and Safety Act |
The education, knowledge, skills and procedures required as defined by the ARRT in order to practice limited radiography; an examination created by the ARRT to ensure competency in the aforementioned areas that candidates may take and pass in order to obt | Limited Scope of Practice in Radiography |
A one-time process of initially recognizing individuals who have successfully met education preparation standards, passed a certification examination, and complied with a defined standard of ethics within a profession. | Certification |
A procedure required to maintain an active status of the certification. | Registration |
Used in referring to state laws; the process by which a person seeks to practice their profession under the jurisdiction of a certain state. | Licensing |
One of the ARRT Examinations available to states to administer for the purpose of licensing radiology technicians to perform bone densitometry examinations. | Bone Densitometry Equipment Operators |
A patient without symptoms of a disease or illness. | Asymptomatic Patients |
A patient exhibiting signs of a disease or illness. | Symptomatic Patients |
Needs that must be met for physiological and psychological survival and growth; Physiological needs are related to survival (food, water, air, shelter); whereas psychological needs relate to requirements for love, belonging, and self-esteem. | Hierarchy of Human Needs |
The ability to share in or experience another's emotions; such as fear, pain or anger. | Empathy |
Acknowledgement of another person's emotions or concern for another person. | Sympathy |
The responsibility and attention toward health, well-being, and safety of clients; demonstrated when medical professionals listen, provide information, help, communicate, show respect, touch and protect. | caring |
A person who speaks on behalf of the patient; puts the patient's best interest first; asserts the patient's rights; and works to provide the patient with information, support, and services needed | Patient Advocate |
The difference between cultures; including language, religion, beliefs, traditions, social forms and ways of life. | Cultural Diversity |
A process by which information is exchanged through individuals through a common system of symbols, signs, or behavior. | Communication |
Order in which authority and power in an organization is wielded and delegated from top management to every employee at every level of the organization. | Chain of Command |
A document that indicates the duties, ideals, values and goals of a radiologic technologist. | Code of Ethics |
Learning related to a search for truth and a general understanding of values and reality. | Philosophy |
The philosophical study of human behavior or conduct involving the study of various cultures , religions, groups and individuals. | Ethics |
Involves the knowledge and application of modern medical technologies. | Biomedical Ethics |
Involves the knowledge and application of modern medical technologies. | Bioethics |
In the Health-Related professions, standards of conduct that relate to the duties and obligations of health care practitioners. | Professional Ethics |
Freedom to govern one's self and make one's own decisions according to the one's own moral principles. | Autonomy |
An individual's right to disclosure of all information related to a medical procedure or treatment to assure the person's full understanding for voluntary consent to accept medical care. | Informed Consent |
Ability to function or reason based on age, condition, illness, memory, judgement, or other status. | Mental Capacity |
An exception to the rule of informed consent; refers to a situation in which a person is unconscious or when a life-threatening emergency exists and no one is available to provide legal permission. | Implied Consent |
A patient's legal and ethical right to privacy. | Confidentiality |
In Healthcare; a duty to others to provide or improve conditions that promote physical and emotional well-being. | Beneficence |
In Healthcare; to prevent harm or to cause no harm to another person. | Nonmalificence |
The balancing and fair distribution of medical care, facilities, and resources for society. | Justice |
Laws enacted by legislative bodies, such as the United States Congress or State Legislative bodies. | Statutes |
Statutes written by boards or agencies that have been established by legislative bodies for areas where certain kinds of expertise are required to develop specific regulations. | Administrative Regulations |
System of applied law that usually develops in the absence of codified written laws or laws enacted through legislation (Pertinent Statutes). | Common Law |
The Highest Order of Law; the branch of public law of a nation or state. | Constitutional Law |
Any willful attempt or threat to inflict injury upon the person of another. | Assault |
Any unlawful touching of another that is without justification or excuse. | Battery |
The conscious restraint of the freedom of another person without proper authorization, privilege, or consent of that individual. | False Imprisonment |
The omission to do something that a reasonable person would do or the doing of something that a resonable or prudent person would not do. | Negligence |
The International failure to perform a manifest duty reckless disregard of the consequences as affecting the life or property of another. | Gross Negligence |
Legal term for both negligence, which may be unintentional and gross negligence, which is intentional. | Torts |
The act of bringing harm to another person's reputation through libel (Written Word) or slander (Spoken Word). | Defamation |
A legal order to withhold CPR or ACLS in the event that a patient's heat were to stop or they were to stop breathing in respect to the wishes of the patient. | Do Not Resuscitate (DNR) |
"The thing speaks for itself" a situation where the injured person in no way contributed to his/her injury. | Res Ispa Loquitur |
"Let the Master Answer" a legal doctrine that holds an employer or agency responsible for the wrongful actions of the employee if performed in the course of employment within the scope of the agency. | Respondent Superior |
Enacted in 1990, a law intended to protect persons with disabilities that guarantees the civil rights of persons with disabilities in the United States. | Americans with Disabilities Act (ADA) |
A law written and implemented to provide health insurance reform and administrative simplification. | Health Insurance Portability and Accountability Act (HIPAA) |
The prevention of the spread of infectious conditions and diseases. | Infection Control |
Opportunistic Infections; a group of pathogenic microorganisms that are common in medical settings. | Nosocomial Infections |
An inflammatory process in response to a disease causing organism. | Infection |
An object that has been contaminated with a pathogen and serves to spread disease. | Fomite |
An infected insect or animal that passes disease through a bite (ticks, fleas, lice). | Vector |
Organisms that cause disease that are transmitted through the environment by dust or droplet contamination. | Airborne Pathogens |
The absence of all disease-producing microorgamisms. | Asepsis |
The destruction of microorganisms by using chemical methods. | Disinfection |
Procedures or techniques used to destroy microorganisms before they enter the body. | Surgical Asepsis |
A set of procedural directives and guidelines published by the CDC to prevent parenteral, mucous membrane, and nonintact skin exposures of healthcare workers to bloodborne pathogens. | Universal Precautions |
A set of safeguards designed for patients documented or suspected to be infected with highly transmissible or epidemiologically important pathogens for which additional precautions beyond standard precautions are needed to interrupt transmission in a hosp | Transmission-Based Precautions |
The science of fitting the job to the worker. | Ergonomics |
A policy prohibiting staff from manually lifting or transporting a patient. | No Manual Lift Policy |
Measures that let us know how a patient is doing on very basic levels for functioning-body temperature, pulse rate, blood pressure and respiration rate. | Vital Signs |
Rhythmic dilation of an artery produced by the flow of blood into the vessel by contraction of the heart. | Pulse |
The exchange of oxygen and carbon dioxide in the lungs. | Respiration |
The force of the flow of blood exerted against the walls of the blood vessels. | Blood Pressure |
A bodily reaction in response to a drug or foreign substance (flushing of the skin, exhibition of hives, nausea, loss of breathing and even death). | Anaphylactic Reactions |
A serious form of shock due to extreme sensitivity to a drug or foreign substance. | Anaphylactic Shock |
A protein that , when introduced to the body, causes the formation of antibodies against it. | Antigen |
A collection of fluid or blood in the sac surrounding the heart that causes compression ad prevents normal heartbeat functions. | Cardiac Tamponade |
A Blue Discoloration. | Cyanosis |
Profuse perspiration. | Diaphoresis |
Convulsion or coma occurring in a pregnant or newly delivered woman; can be predicted by the presence of protein in the urine and rising blood pressure. | Eclampsia |
A passing disturbance of brain function. | Epilepsy |
Temporary loss of consciousness due to loss of blood supply to the brain. | Fainting |
An increase in the amount of air entering the alveolar sacs. | Hyperventilation |
Obstruction of the pulmonary artery or one of its branches by undissolved matter. | Pulmonary Embolus |
(CVA) An interference with blood supplied to the brain. | Stroke |
Temporary loss of consciousness caused by dropping blood pressure. | Syncope |
A clot of blood formed and lodged within a blood vessel. | Thrombus |
A "mini stroke" in which symptoms of a stroke are mild and temporary and is caused by a partial blood vessel occlusion. | Transient Ischemic Attack (TIA) |
A toxic condition produced by the retention of excessive byproducts of protein metabolism in the blood. | Uremia |
A sensation of having objects or the entire room spinning. | Vertigo |
Nose bleed. | Epistaxis |
A branch of science that deals with matter and energy and their relation to each other. | Physics |
The International System of Units which gives the internationally agreed-upon metric and non-metric units for weights and measure. | System Internationale d'Unites (S.I.) |
The amount or quantity of matter. | Mass |
The S.I. base unit of length; defined as the distance light can travel in a vacuum in 1/299,792,485ths of a second. | Meter |
The S.I. unit of exposure dose for x-rays and gamma rays; formerly known as Roentgen (R). | Coulomb Per Kilogram |
The S.I. unit of exposure dose for x-rays and gamma rays; now known as Coulomb per kilogram. | Roentgen (R) |
The S.I. unit of radiation absorbed dose; also expressed as joules per kilogram. | Gray (Gy) |
100 ergs of energy absorbed by 1 gran of absorbing material. | Radiation Absorbed Dose |
The S.I. unit of dose equivalent; also expressed as 1 joule per kilogram. | Sievert (sv) |
The unit of the quantity of absorbed dose equivalent of any type of ionizing radiation that produces the same biologic effect as one rad of radiation. | Radiation Equivalent Man |
a material that has definite and constant composition. | Substance |
A combination of two or more substances. | Mixture |
A chemically distinguishable substance consisting of only one kind of atom. | Element |
The physical principle that energy can neither be created nor destroyed but only converted from one form to another. | Law of Conservation |
The ability to do work; usually divided into kinetic energy-energy in motion and potential energy-energy of position; measured in joules. | Energy |
The expenditure of energy; the application of force over a distance. | Work |
The S.I. base unit of energy | Joule |
electromagnetic waves or particular matter emitted as a value of electronic or atomic transitions | Radiation |
Energy possessed when an object is in motion; expressed in terms of mass and velocity. | Kinetic Energy |
The rate of motion of an object; measured in meters per second. | Velocity |
Stored Energy, also known as energy in position, depends on the object's height above the ground. | Potential Energy |
The tendency of a moving body to remain in motion or a stationary body to remain at rest. | Inertia |
The blurring in an image resulting from voluntary or involuntary patient movement. a major factor in reducing image clarity and increasing distortion. | Momentum |
Separate packets of energy constituting the electromagnetic radiation. | Quantum |
The smallest particle that and element can be reduced to while still maintaining it chemical identity. | Atoms |
A tabular arrangement of the elements according to their atomic number so that elements with similar properties are in the same column. | Periodic Table of Elements |
The number of protons in a nucleus; the atomic number is unique to a specific element. | Atomic Number |
The number of protons and neutrons in a nucleus. | Atomic Mass Number |
Chemical combinations atoms into substances. | Molecules |
A substance composed of like molecules. | Compounds |
A positively charged fundamental particle found in the nucleus of an atom. | Proton |
An uncharged fundamental particle found in the nucleus of an atom. | Neutron |
A negatively charged fundamental particle found in orbitals around an atomic nucleus. | Electron |
The Center of an atom containing neutrons and protons. The portion of a cell containing the DNA. | Nucleus |
Any subatomic particle found in the nucleus of an atom; can be either protons or neutrons. | Nucleons |
An element that has the same chemical identity (Same Atomic Number) but different amount of neutrons in the nucleus resulting in a different atomic mass. | Isotope |
An electrically charged particle. | Ion |
The amount of energy needed to remove an electron from its orbital shell; the closer to the nucleus an electron is, the more binding energy it has. | Binding Energy |
The rule that the number of electrons in the outermost shell of an atom; can never exceed 8 electrons. | Octet Rule |
Devoid of active chemical properties; as the inert gasses. | Inert |
Describes an atom that has exactly eight electrons in the outermost shell. | Chemically Stable |
The number of electrons in the outermost shell of an atom; also known as its chemical combining characteristic | Valence |
Radiation that does not cause the production of charged particles (ions). | Non-ionizing/ionizing |
Ionizing radiation consisting of physical particles such as electrons or neutrons. | Particulate Radiation |
Radiation consisting of an electrical component and an magnetic component; described in terms of energy, wavelength, and frequency. | Electromagnetic Radiation |
High-energy electromagnetic radiation resulting from radioactive decay of the nucleus. | Gamma Radiation |
Separate packets of energy constituting the electromagnetic radiation. | Quanta |
The massless particle that conveys electromagnetic force, x-rays and light. | Photon |
The S.I. unit of frequency; expressed as 1/s. | Hertz |
Product of radioactive decay composed of two protons and two neutrons; a heluim nucleus. | Alpha Particles |
A product of radioactive decay physically identical to an electron. | Beta Particles |
The normal amount of radiation expected from unavoidable natural and artificial sources. | Environmental Radiation |
The normal amount of radiation expected from unavoidable natural and artificial sources. | Background Radiation |
A way to explain to a patient how much radiation the receive from a medical examination compared to the amount of radiation received while spending time in their natural living environment. | Background Equivalent Radiation Time (BERT) |
A positively charged atom as a result of the loss of an electron. | Cation |
A negatively charged atom as a result of the addition of an electron. | Anion |
Any process that prevents x-ray photons from reaching the patient or radiographic film. | Attenuation |
The secondary radiation produced as a result of interaction of the primary radiation beam with atoms of an object. | Scatter Radiation |
When a low energy x-ray photon interacts with an atom and the target atom releases another x-ray photon having the same wavelength and energy as the original, resulting in no energy transfer and no ionization. | Coherent Scattering (Classical or Thompson's) |
An incoming x-ray photon transferring all of its energy to an inner-shell electron, causing the ejection of the newly formed photoelectron from its shell and the transfer of an outer electron to fill the vacancy, emitting a new x-ray photon. | Photoelectric Effect |
When an x-ray photon interacts with an electron in the outer orbital shell ejecting an electron and ionizing the atom while redirecting the original x-ray photon with decreased energy and a longer wavelength. | Compton Effect |
When an extremely high-energy x-ray photon strikes an atomic nucleus, thus ejecting a nuclear fragment. | Photodisintegration |
An extremely high energy x-ray photon that interacts with the nucleus of an atom and disappears leaving two electrons. | Pair Production |
An electron released or ejected from a substance by photoelectric effect. | Photoelectron |
An x-ray photon emitted from the atom when an outer-shell electron fills an inner-shell vacancy. | Characteristic Radiation |
The uppermost point, the position of maximum positive value, of a progressive wave. | Crest |
A type of luminescence or "light up" that occurs when certain phosphors (Calcium Tungstate) absorb radiation. | Fluoresce |
Electrical current that periodically alternates its direction back and forth. | Alternating Current |
The movement of electrical charge. | Electrodynamics |
A material that carries electricity easily. | Conductor |
A material that resists the flow of electricity. | Insulators |
The process of imparting a charge to objects; results from either the deficiency or excess of electrons in an atom. | Electrification |
The difference in electrical potential between two points on an electrical conductor. | Potential Difference |
The S.I. unit of potential difference. | Volts |
The flow of electrons in an electrical circuit. | Current |
The S.I. base unit of electrical current; also expressed as 1 coulomb/second | Amperes |
The S.I. Unit of electrical resistance. | Ohms |
The ability of certain material to attract iron and other metals. | Magnetism |
The negatively charged side of an electrical circuit; the side of an x-ray tube where electrons are produced. | Cathode |
Is located outside the glass x-ray tube and consists of a series of electromagnets spaced equally around the neck of the x-ray tube. The stator induces the rotation of the rotor. | Stator |
A window segment constructed at the point where the primary x-ray beam exits the glass envelope of the x-ray tube. | Port |
The heated wire in the cathode of an x-ray tube where electrons are produced. | Filament |
A metal commonly used to construct filaments; desirable for its high melting point and because it does not readily turn into gas. | Thoriated Tungsten |
An element turning into its vapor state. | Vaporize |
A filament material; desirable because of its high melting point. | Rhenium |
A filament material; desirable because of its high melting point. | Molybdenum |
The production of electrons by the heating of the x-ray tube filament. | Thermionic Emission |
Is located within the glass x-ray tube and consists of copper bars and soft iron designed around a molybdenum shaft. The rotor is responsible for rapidly rotating the anode when the stator is depressed. | Rotor |
The positively charged side of an electrical circuit; the target side of an x-ray tube. | Anode |
The metal cup surrounding the filament in and x-ray tube that focuses the electron beam in the x-ray tube. | Focusing Cup |
The effect whereby the apparent focal spot is smaller than the actual focal spot of an x-ray tube resulting from the electron stream striking an angled target. | Line Focus Principle |
The region of the x-ray tube target where the electron beam is focused. | Focal Spot |
The actual size of the focal spot on the anode (on which the electron stream impacts). | Actual Focal Spot |
The size of the focal spot that is perceived on the film. | Effective Focal Spot |
Diminished x-ray intensity at the anode end of an x-ray tube due to self-absorption in the anode. | Heel Effect |
Radiation comprising of photons that occurs as a results of electrons interacting with atoms of the target material. | Bremsstrahlung Interactions |
Interactions of incoming electron with an inner-shell electron. | Characteristic Interactions |
Any x-ray protons that escape from the housing except at the window or port. | Leakage Radiation |
The light source used to produce x-rays. | Primary Radiation |
An opening provided in the x-ray tube housing to permit unrestricted exit for the useful x-ray photons from the glass envelope. | Window |
The use of a filter to attenuate x-rays or to remove low energy radiation from the x-ray beam. | Filtration |
An adjustable x-ray beam restrictor that alters the quantity and quality of the x-ray beam. | Collimator Shutters |
A decrease in energy of a wave or a beam of particles, occurring as the distance from the source increases as a result of absorption, scattering, spreading in three dimensions. | Attenuate |
Also called exit radiation or image-forming radiation, refers to radiation being responsible for the film darkening resulting in the latent image. | Remnant Radiation |
The maximum heat capacity of an x-ray tube. | Tube Heat Capacity |
A position in which the patient lies face up on a tilted table or bed with the head lower than the pelvis. | Trendlenburg Position |
An electromagnetic device that increases the low voltage or the primary circuit to the level needed by the secondary circuit. | High-Voltage Transformer |
The part of an x-ray machine circuit on the input side of the high voltage transformer; begins at the main power switch and includes the autotransformer, line voltage compensator, kilovolt peak meter, circuit breaker, timers and the filament circuit. | Primary Circuit |
A transformer consisting of two windings on a single core; used in x-ray machines to vary the line voltage to the primary side of the step-up transformer. | Autotransformer |
A device on the primary side of the autotransformer that increases or decreases the line voltage if there is a drop or surge in the incoming line voltage. | Line Voltage Compensator |
A device connected to the autotransformer with the purpose of measuring the voltage output of the autotransformer. | Kilovolt Peak Meter |
A device used to automatically terminate the electrical current in the event that predetermined values for exposure, current, etc. are exceeded. | Circuit Breaker |
The electric circuit connected to the autotransformer responsible for delivering electrical current to the x-ray tube. | Filament Circuit |
An exposure-timing device that is controlled and driven by an electrical synchronous motor. | Synchronous Timer |
The product of x-ray tube current and exposure time; a measure of x-ray quantity | Milliamperage-Seconds (mAs) |
Records the mAs on the secondary side or the high voltage step-up transformer and terminates the x-ray exposure once a pre-determines mAs value is recorded. | mAs Timer |
Detector timer designed to terminate the exposure time when the image receptor has received the proper amount of radiation. | Automatic Exposure Controls (AECs) |
An exposure-timing device that uses a light-sensitive photomultiplier tube placed behind a fluorescent screen to terminate the exposure after a predetermined charge that corresponds to the density required for a specific examination. | Phototimer |
Responsible for increasing the voltage of the primary circuit; begins and ends with the secondary side of the step-up transformer. | Secondary Circuit |
A type of rectification that utilizes only one half of the AC voltage pulse in which the current is directed by only one or two diodes. | Half-Wave Rectification |
A type of rectification that utilizes both halves of the AC voltage pulse in which four diodes are used in order to create a positive current flow in one direction. | Full-Wave Rectification |
A device used in radiography to measure the volume of tissue thickness of a body part. | Caliper |
An exposure or technique chart that uses and optimum kilovoltage to penetrate a given part of the body and a varied mAs value based on the part thickness and projection. | Fixed Kilovoltage Technique |
An exposure or technique chart that uses microcomputers to determine kVp and mAs (time). | Automatic Program Radiography (APR) |
A technique designed to use high kilovoltage for penetration, usually 100 kVp and greater | High kVp Technique |
Properties of a quality diagnostic radiograph, namely, density and contrast. | Photographic Properties |
Properties of a quality diagnostic radiograph, namely, recorded detail and absence of distortion and magnification. | Geometric Properties |
Factors that control production of the visible radiographic image. | Exposure Factors |
The unit of x-ray tube current. | Milliamperage (mA) |
One of the exposure factors; the period when something occurs; measured in seconds or milliseconds. | Time |
An exposure factor that defines the peak or highest amount of current applied to the x-ray tube. | Kilovoltage Peak |
The distance between the radiation source and the image receptor that influences recorded detail and density; the greater the SID, thee smaller the geometric blur, which leads to improved recorded detail. | Source-to-Image Distance (SID) |
Overall blackness of the radiographic image; controlled by mAs. | Density |
A measure of the heat accumulated in the anode of an x-ray tube due to self-absorption in the anode; capacity calculated by multiplying mA, time and kVp. | Heat Unit (HU) |
"Undesirable" density (film darkening); obscures image details. | Film Fog |
A factor that sometimes needs to be adjusted for various thickness ranges of an anatomical structure. | Kilovoltage |
The distance between the radiation source and the image receptor that influences recorded detail and density; the greater the SID, the smaller the geometric blur, which leads to improved recorded detail. | Distance |
Mathematical law that states that the intensity (of radiation) is inversely proportional to the square of distance. | Inverse Square Law |
In radiographic terms, the visible difference between any two areas of radiographic density. | Contrast |
Contrast resulting from the amount of radiation transmitted by a particular body part as a results of the differential absorption characteristics of the tissues and structures of the part. | Subject Contrast |
The ability of the film emulsion to react to radiation and to record a particular range of densities. | Film Contrast |
Control of the field size of and x-ray bean tat limits the amount of scattered radiation interacting with the body. | Beam Restriction |
Use of filters added to the radiation beam to eliminate non useful, soft, low-energy (long wavelengths) radiation to improve contrast. | Beam Filtration |
Compression of tissue reduces the tissue thickness to allow improved penetration of the x-ray beam. | Compression of Tissue |
The degree of definition, of the sharpness of the structural lines, as recorded in the radiographic image. | Recorded Detail |
Variation from normal shape; a misshapen radiographic image. | Distortion |
Enlargement of the size of the actual anatomical part. | Magnification |
The smaller filament in the focusing cup of the cathode assembly of the x-ray tube. | Small Focal Spot |
The larger filament in the focusing cup of the cathode assembly of the x-ray tube. | Large Focal Spot |
The practice/rule of placing the object (Anatomy) as close to the image receptor as possible in order to reduce magnification and geometric blur. | Object-to-Image Distance (OID) |
Results in image blurring in the center of the film; occurs when cassettes are constantly opened for loading, unloading, and cleaning. | Screen-Film Contact |
Ability of crystals within the film emulsion to efficiently record information. | Film Resolution |
The blurring in an image resulting from voluntary or inj=voluntary patient movement; a major factor in reducing image clarity and increasing distortion. | motion |
The center of the x-ray beam. | Central Ray |
Screens composed of fluorescent phosphors that intensify the action of radiation. | Intensifying Screens |
A radiographic accessory constructed with lead strips to reduce the amount of scatter radiation from a given exposure reaching the image receptor. | Grids |
A position in which the body part/patient is rotated 45 degrees from the image receptor. | Oblique Position |
The physical appearance of the body or body build. | Body Habitus |
A body type that is average or normal body shape and represents about 50% of the population. | Sthenic |
A body type that is slender or thin | Hyposthenic |
A body type that is extremely slender and generally frail in appearance and usually weak | Asthenic |
A body type that is large and stocky | Hypersthenic |
The position used to describe the relationship of body parts to each other. Standing in the erect position with the body facing forward, the feet together, and the arms down by each side with the palms of the hands facing forward. | Anatomic Position |
An invisible plane used to identify the body in different sections and the location of bodily structures and movements. | Body Planes |
One of the three primary body planes, also referred to as the frontal plane. | Coronal |
One of the three primary body planes; divides the body into left and right portions. | Sagittal |
One of the three primary body planes; horizontal or axial plane that is at right angles to the vertical axis of the body. | Transverse |
Of or closest to the front. Used in positioning to indicate structures toward the front of the body; In positioning, used to describe the patient facing the film. | Anterior |
Of or closest to the back. Used in positioning to indicate structures toward the back of the body; in positioning, used to describe the patient facing the radiographic tube. | Posterior |
Exterior landmarks that may be palpated to locate specific bones, especially vertebral bodies | Surface Landmarks |
A positioning terminology, refers to the body position standing. | Erect |
A positioning terminology, refers to the body position lying down. | Recumbent |
A positioning terminology, refers to the body lying on the back. | Supine |
A positioning terminology, refers to the body position lying face down. | Prone |
Body position lying down with a horizontal x-ray beam. | Decubitus |
A characteristic of an image that measures the perceived image degradation (typically, compared to and ideal or perfect image). | Image Quality |
Using a set of criteria or a checklist in preparation of image production in order to avoid errors and produce a diagnostic-quality radiograph | Image Production |
A list of requirements of image quality, positioning, and exposure factors that a radiograph must display in order for the radiograph to be of diagnostic quality | Evaluation Criteria |
The assessment of the image in terms of photographic effect for photographic factors, geometric factors and accurate radiographic position | Image Evaluation |
Properties of a quality diagnostic radiograph (Density and Contrast) | Photographic Factors |
Factors connected with the geometry of image formation | Geometric Factors |
A specific body part position, such as supine or prone; refers to the patient's physical position | Radiographic Position |
Discovered x-rays in 1895 | Wilhelm Conrad Roentgen |
A branch of the biological sciences which involves the study of the effects of ionizing radiation on living tissue | Radiation Biology |
The imparting of charge to an atom by the removal or addition of an electron | Ionization |
The transference of x-ray energy to the atoms of human tissue. | Absorption |
The amount of radiation energy absorbed in tissue; Measured in Grays | Absorbed Dose |
Also called reduction division; Creates 2 identical cells each containing only 1/2 (23) of the usual 46 chromosomes | Meiosis |
Division of a cell resulting in 2 cells, each containing 46 chromosomes. | Mitosis |
The measure of the response of a biological organism to radiation | Radiosensitivity |
Explains the radiosensitivity of various human cells to ionizing radiation | Law of Bergonie and Tribendeau |
A non mitotic or non division form of cell death, which occurs when cells die without attempting division during the interphase | Apoptosis |
2 methods of radiation delivery (1) a protracted dose of radiation is delivered continuously at a lower dose rate (2) a fractionated dose is delivered at the same dose rate but divided into equal fractional quantities of radiation | Dose Fractionation and Protraction |
A method used to calculate the effective absorbed dose for all types of ionizing radiation | Absorbed Dose Equivalent (ADE) |
A point or level of radiation exposure (dose) at which a response or reaction first occurs | Dose-Response Relationship |
The loss of energy to matter by radiation; measured in keV | Linear Energy Transfer (LET) |
A measure of the biological effects of different types of radiations; the ratio of the effect of a standard radiation to a test radiation | Relative Biological Effectiveness (RBE) |
Effect that occurs when x-ray photons directly interact with a "target" or master (critical) DNA molecule | Direct Effect |
Effect that occurs when a photon strikes a noncritical molecule, usually water, and the noncritical molecule then transfers the ionization energy to the critical DNA molecule | Indirect Effect |
An event in which a water molecule is ionized resulting in free ions capable os recombining with other free radicals to form new molecules | Radiolysis |
The theory which states that there are one or two critical targets for radiation to damage in a cell | Target Theory |
Effect of radiation on the human body other than the gonads; responsible for cancer and cataracts | Somatic |
Effects that may not be apparent in the exposed individual but which may be passed on to future generations through genetically damaged chromosomes | Genetic (Hereditary) Effects |
Effects that occur in a random way and whose severities are not dose dependent | Stochastic Effects |
Somatic effects that are directly related to the dose of ionizing radiation received; as the radiation dose increases the deterministic effect increases | Deterministic Effects |
Also called Radiation Illness; Occurs after humans receive large doses of ionizing radiation to the entire body within a short period of time | Acute Radiation Syndrome (ARS) |
A necessary decision as to the potential diagnostic benefits gained from an imaging examination versus the potential biologic harm resulting from radiation exposure | Benefit-Versus-Risk Principle |
A U.S. government agency responsible for regulating the nuclear energy industry | Nuclear Regulatory Commission (NRC) |
The maximum amount of radiation allowed under radiation safety standards; defined for the whole body, body parts and calendar periods. MPD has been replaced by effective-absorbed dose-equivalent limits | Maximum Permissible Dose (MPD) |
A prescribed set of dose limits that are based on calculations of various risks of cancer and genetic effects to tissues and organs exposed to radiation | Effective Dose-Limiting System |
Effects that occur in a random way and whose severities are not dose dependent | Stochastic Effects |
Physiological effects that appear in the individual within days or weeks after a significant external exposure to radiation (nausea, hair loss, sore throat, hemorrhage, diarrhea) | Early Somatic Effects |
Physiological effects that appear in the individual after months to years of significant external exposure to radiation (cancer-leukemia, birth defects, cataracts) | Late Somatic Effects |
Report that states that for educational and training purposes, radiation workers less than 18 years old be limited to an annual dose limit of 1 mSv (0.1 rem) | NCRP Report No. 116 |
A patient examination that is repeated due to inadequate patient preparation, technical factors or operator error | Repeat Examinations |
A simple bean-limitation device consisting of a flat piece of lead with a hole in the middle | Aperture Diaphragm |
A simple beam-limitation device consisting f a circular metal tube with a flared end. | Cone |
The process of restricting and confining a beam of radiation to a given area | Collimation |
A collimation device that automatically limits an x-ray beam according to the size of the image receptor | Positive Beam-Limiting (PBL) System |
Attenuation of the primary x-ray bean as a result of its passage out of the x-ray tube through the insulating medium and tube window | Inherent Filtration |
Sheets of metal placed in the path of the primary x-ray beam to make it a more penetrating beam | Added Filtration |
a radiographic accessory constructed with lead strips to reduce the amount of scattered radiation from a given exposure reaching the image receptor | Grid |
A technique t reduce scattered radiation by increasing the distance between the patient and the surface of the film or image receptor; used when a grid is unavailable | Air-Gap Technique |
Protection of the patient's gonads form direct exposure by placing shielding material between the x-ray beam and the patient's gonads | Gonadal Shielding |
The key principles of radiation protection: time, distance and shielding | Cardinal Principles |
The radiation output wighted time during the week that the x-ray unit is actually delivering radiation | Workload (W) |
Used to modify the shielding requirement for a particular barrier by taking into account the fraction of the workweek that the space beyond the barrier is occupied. | Occupancy Factor (T) |
A protective barrier located perpendicular to the line of travel of the primary x-ray beam. | Primary Protective Structural Shielding |
A protective barrier that runs parallel to the primary beam and protects diagnostic radiology personnel from secondary (leakage) radiation | Secondary Protective Structural Shielding |
A report on Medical Exposure of Pregnant and Potentially Pregnant Women that discusses the risks associated with fetal exposure | NCRP Report No. 54 |
An obsolete guideline that states that pelvic of abdominal x-ray examinations of women of child-bearing age be done only in the first 10 days following the onset of menstruation | Ten-Day Rule |
A key medical organization composed of diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians and medical physicists. | American College of Radiology (ACR) |
A personnel radiation monitor that measures radiation exposure by the use of film | Film Badge |
A personnel radiation monitoring device, which, when heated, produces light proportional to the radiation exposure | Thermoluminescent Dosimeter (TLD) |
A small, pocket-sized ionization chamber used for monitoring radiation exposure of personnel | Pocket Ionization Chamber |
The creation of computerized image files and transferring them to computers located elsewhere in a network or across the internet | Digital Imaging |
Procedure in which images may be electronically transmitted over distances to other healthcare facilities | Teleradiology |
Number of bits per poxel | Bit Depth |
A complex technology that involves the use of a computer to prepare digital images. | Digital Imaging Processing |
The basic formation of a two-dimensional image that consists of Columns (M) and Rows (N) of pixels | Matrix |
Volume of Tissue; represents a single point (pixel) on a three-dimensional matrix | Voxel |
The smallest piece of a two-dimensional, rectangular image array of square pixels that make up the matrix. | Pixels |
Technique in which x-ray absorption is quantified by assignment of a number to the amount of x-rays reaching the detector; the information is manipulated by a computer to produce the optimal image | Digital Radiography (DR) |
Digital Radiography that records images on a photostimulable phosphor plate (PSP) instead of film/screen image receptors | Computed Radiography (CR) |
Changes analog signal to digital image of patient part being examined | Analog-to-Digital Converter (ADC) |
A methodology that includes data acquisition, image processing, image display, storage and archiving, and image communication | Digital Image Production |
A material used to capture radiographic images in computed radiography systems | Photostimulable Phosphor (PSP) |
A process in which the digital image is converted into an analog signal that can be displayed on a monitor. | Digital-to-Analog Converter |
The process of recording a radiographic image without a separate image reader cassette | Direct Capture |
Sensitivity range of exposure of a computed radiographic image receptor, relative to the manufacturer's imaging plate exposure data; determines overexposure or underexposure of the image as set by the radiographer | Exposure Index (EI) Number/Exposure Index Value |
A range of data the radiographer can manipulate on a digital radiograph in order to adjust the image contrast | Window Width |
A range of data the radiographer can manipulate on a digital radiograph in order to adjust the image brightness | Window Level |
A function that defines the ability of a detector to transfer that spatial resolution of sharpness characteristic to an image | Modulation Transfer Function (MTF) |
The ability of a digital imaging system to demonstrated small details of an object; also refers to the sharpness of the structural edges of an object | Spatial Resolution |
The range of x-ray exposure over which a meaningful diagnostic image can be obtained | Dynamic Range |
The ability of a digital radiography system to display subtle changes in shades of gray of a radiographic image; also known as Radiographic Contrast | Contrast Resolution |
Occurs when a patient's imaged anatomic structure(s) are smaller than the detector element size; results in a "smeared" appearance and reduced contrast | Partial Volume Effect |
Anything that interferes with the formation of a radiographic image | Noise |
A set of values defining the spatial resolution for a specific digital detector system | Line Speed Function |
A type of noise caused by insufficient sampling resulting in artifacts on a radiograph | Aliasing |
The ratio of the amount of total signal to the amount of noise present in a digital image | Signal-to-Noise Ratio (SNR) |
A failure of the imaging system to record densities; usually caused by insufficient mAs | Quantum Mottle |
The range between the minimum and maximum radiation exposure necessary in order to produce an acceptable range of densities | Exposure Latitude |
A measurement of the percentage of the x-rays that are absorbed when they strike the image receptor; how efficient a system converts x-ray signals into a useful output image | Detective Quantum Efficiency (DQE) |
Used to describe the nominal radiographic exposure required to obtain a diagnostic image; similar to speed | Exposure Class |
A measure of how far the actual exposure index value deviates from the target exposure index value for a specific radiographic projection | Deviation Index |
A histogram of the IP information used to compensate for underexposure and overexposure in comparison with a "known" histogram for specific anatomy | Scanned Histogram |
a step in the post-processing process in which a look-up table (LUT) is applied that converts the image data from a linear to S-shaped image | Grayscale Rendition |
a post-processing algorithm applied to optimize the image contrast and brightness or density to enhance the diagnostic quality of an image; AKA contrast scaling, gradation processing, tone scaling and latitude reduction | Contrast Enhancement |
Cropping the electronic image of a radiograph in order to remove the white collimation borders from a digital image and thus reduce veil glare; should never compensate for poor collimation | Shuttering |
Part of the pre-processing phase in which the appropriate raw data min and max values to be used for image grayscale rendition are identified | Exposure Recognition |
a post-processing algorithm used to adjust the sharpness or detail of the image; Spatial Frequency Processing | Edge Enhancement |
Cropping the electronic image of a radiograph in order to remove the white collimation borders form a digital image and thus reduce veil glare; should never be used to compensate for poor collimation | Electronic Collimation |
Provides information to the image reader about the way anatomy is oriented on the image plate and the direction or location or the anatomy on the image | Image Orientation |
Cropping the electronic image of a radiograph in order to remove the white collimation borders form a digital image and thus reduce veil glare; should never be used to compensate for poor collimation | Masking |
Techniques used to correct dead pixels or dead rows or columns of pixels | Interpolation Techniques |
A computerized database used by radiology departments to store, manipulate, and distribute patient radiological data and imagery | Radiology Information System (RIS) |
The maximum achievable spatial resolution | Nyquist Frequency |
A distracting presence of whit borders around the digital image; allows extra light to enter the eye while viewing a digital image | Veil Glare |
The addition of text or markers to a digital image through specialized software | Image Annotation |
Software correction performed to equalize the response of each pixel to a uniform x-ray beam | Flatfielding |
An electronic database used in a hospital to store, generate and retrieve patient information. | Hospital Information System (HIS) |
A systematic network for sending, receiving and storing all digital images within a medical imaging department | Picture Archiving and Communication System (PACS) |
System that transfers images and other medical information between computers | Digital Imaging and Communication in Medicine (DICOM) |
Standard protocols used in communication between the health information systems and radiology information systems | HL-7 Standards |