183 Healthcare: Radiation Safety
Glossary
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A
- Absorbed Dose. The amount of energy deposited by ionizing radiation per unit mass of tissue, measured in Grays (Gy), which helps assess potential biological effects of radiation exposure.
- Acute Radiation Syndrome (ARS). A severe illness caused by a high dose of ionizing radiation over a short period, characterized by symptoms such as nausea, vomiting, diarrhea, and decreased blood cell counts.
- Active Dosimeter. A real-time radiation detection device that provides immediate feedback on radiation exposure levels, often used in high-risk environments.
- ALARA (As Low As Reasonably Achievable). A principle in radiation safety management aimed at minimizing exposure to ionizing radiation by implementing practical measures.
- Alpha Radiation. A type of ionizing radiation consisting of helium nuclei. It is highly ionizing but has low penetration power, usually stopped by skin or paper.
- Alpha Scintillation Counter. A device used to detect and measure alpha radiation by converting alpha particles into light pulses, which are then amplified and counted.
B
- Background Radiation. The naturally occurring radiation from environmental sources such as cosmic rays, soil, rocks, and even the human body. It serves as a baseline for assessing additional exposure from artificial sources.
- Beam Collimation. The process of narrowing the X-ray or radiation beam to focus only on the area of interest, reducing unnecessary exposure to surrounding tissues.
- Beta Radiation. Ionizing radiation composed of fast-moving electrons or positrons. It has moderate penetration and can be stopped by plastic or glass.
- Bioassay. A method of assessing internal radiation exposure by analyzing biological samples such as urine or blood to detect radioactive materials.
C
- Cloud Chamber. A radiation detection device that visualizes the paths of charged particles by creating condensation trails in a supersaturated vapor.
- Computed Tomography (CT) Dose Index (CTDI). A measure of the radiation dose in a CT scan, reflecting the exposure for a single slice of the scan and helping to estimate overall patient exposure.
- Contamination Control. Procedures to prevent the spread of radioactive materials, including the use of barriers, cleaning protocols, and monitoring equipment.
D
- Dosimeter. A device worn by individuals working with or around radiation to measure and record exposure levels over time.
E
- Effective Dose. A measure of radiation exposure that accounts for the type of radiation and sensitivity of different tissues or organs, expressed in Sieverts (Sv). It provides a standardized way to assess the overall risk of exposure.
- Emergency Radiation Procedures. Protocols for managing radiation emergencies, including evacuation, decontamination, medical assessment, and the use of potassium iodide to block radioactive iodine uptake.
F
- Fluoroscopy. A medical imaging technique using continuous X-rays to visualize real-time movement within the body, often requiring stringent radiation safety protocols to protect patients and operators.
G
- Gamma Radiation. High-energy electromagnetic radiation emitted from the nucleus of radioactive atoms. It has high penetration power and requires dense materials like lead for effective shielding.
- Geiger-Müller Counter. A widely used portable radiation detector that measures ionizing radiation by detecting particles or photons that ionize gas within a tube.
H
- Half-Life. The amount of time it takes for half of a radioactive substance to decay, reducing its radioactivity by 50%.
I
- Interventional Radiology (IR). A medical specialty using imaging technologies like X-rays, CT, or ultrasound to guide minimally invasive procedures, requiring careful management of radiation exposure for both patients and staff.
- Ionizing Radiation. High-energy radiation capable of removing tightly bound electrons from atoms, creating ions. It is used in medical applications like X-rays and radiation therapy but requires strict safety measures to prevent harm.
- Ionizing Radiation Types. Categories of radiation that can remove electrons from atoms, including alpha, beta, gamma, X-rays, and neutron radiation, each with varying penetration and energy levels.
J
- Joule (J). The SI unit of energy, often used to describe the energy absorbed by matter from ionizing radiation. One Gray (Gy) is equivalent to one joule per kilogram.
K
- K-Edge Filtering. A technique in diagnostic radiology and radiation therapy where filters are used to exploit the K-edge absorption properties of materials to optimize image quality or reduce patient dose.
- Kerma (Kinetic Energy Released per Unit Mass). A measure of the energy transferred from radiation to matter, expressed in units of Gray (Gy). It is a crucial concept in understanding radiation interactions with tissue.
L
- Lead Apron. A protective garment made of lead or lead-equivalent materials, worn during radiological procedures to shield the wearer from scatter radiation.
- Lead Shielding. Protective barriers made of lead used to block or reduce exposure to radiation, commonly used in medical imaging and radiology.
- Liquid Scintillation Counter. A device used to detect low-energy beta radiation by mixing radioactive samples with a scintillation liquid that emits light when radiation is present.
M
- Maximum Permissible Dose (MPD). The highest level of radiation exposure allowed for workers or the general public under regulatory guidelines to minimize health risks.
- Medical Physicist. A healthcare professional specializing in radiation safety, dosimetry, and the technical aspects of medical imaging and radiation therapy to ensure patient and staff safety.
N
- Neutron Detector. A device specifically designed to detect neutron radiation, often using materials like helium-3 or boron trifluoride gas.
- Neutron Radiation. Ionizing radiation consisting of neutrons, primarily encountered in nuclear reactors and weapons, requiring specialized shielding materials like polyethylene.
- Non-Ionizing Radiation. Radiation with insufficient energy to ionize atoms, including ultraviolet, visible light, infrared, and microwave radiation, which poses different safety risks.
O
- Occupational Dose. The amount of radiation exposure received by workers in radiation-related professions, monitored using dosimeters to ensure levels remain within safe limits.
- Occupational Safety and Health Administration (OSHA) Requirements. Federal guidelines to ensure workplace safety in environments involving radiation, including exposure limits, protective equipment mandates, and monitoring requirements.
P
- Passive Dosimeter. A device such as a film badge or thermoluminescent dosimeter (TLD) that measures cumulative radiation exposure over time without providing real-time feedback.
- Personal Protective Equipment (PPE). Specialized clothing and gear, such as lead aprons or thyroid shields, worn by healthcare workers to protect against radiation exposure.
- Photomultiplier Tube (PMT). A component used in radiation detection devices to amplify light signals produced by scintillators, enabling the measurement of very low levels of radiation.
- Potassium Iodide (KI). A medication used in radiation emergencies to protect the thyroid gland from radioactive iodine by saturating it with stable iodine.
- Proportional Counter. A type of gas-filled radiation detector that provides information about the energy of the radiation being detected, useful for distinguishing between types of ionizing particles.
Q
- Quality Factor (Q). A dimensionless factor used in dosimetry to account for the relative biological effectiveness (RBE) of different types of radiation. It modifies the absorbed dose to calculate the equivalent dose.
R
- Radiation Burn. A localized injury caused by exposure to high doses of ionizing radiation, typically resulting in skin redness, blistering, and tissue damage.
- Radiation Dosage. The amount of radiation absorbed by a person or material, measured in units such as Gray (Gy) or Sievert (Sv).
- Radiation Emergency Plan. A detailed strategy for responding to incidents involving radioactive materials, including evacuation, containment, and medical care.
- Radiation Illness Symptoms. Health effects from radiation exposure, including early symptoms like nausea and fatigue, followed by more severe issues such as infections, bleeding, and organ failure in extreme cases.
- Radiation Portal Monitor (RPM). A large-scale detection system used to screen vehicles, containers, or individuals for radioactive materials, commonly deployed at borders and checkpoints.
- Radiation Protection Program. A structured set of policies and procedures designed to ensure the safety of individuals who may be exposed to radiation in healthcare or research environments.
- Radiation Survey Meter. A portable instrument used to measure radiation dose rates or contamination levels in an environment, providing crucial data for safety assessments.
- Radionuclide. A radioactive isotope used in medical imaging or treatment, such as technetium-99m or iodine-131.
S
- Scatter Radiation. Secondary radiation that deviates from its original trajectory after interacting with matter, often necessitating shielding to protect individuals near the source.
- Scintillation Detector. A radiation detection device that uses a scintillating material to convert ionizing radiation into light, which is then measured by a photodetector.
- Sievert (Sv). The SI unit used to measure the effective dose of radiation, accounting for the biological impact of different types and amounts of radiation.
- Silicon Diode Detector. A semiconductor device used to measure ionizing radiation, particularly useful in dosimetry and medical applications.
- Sodium Iodide Detector. A type of scintillation detector commonly used for gamma-ray spectroscopy due to its high efficiency and resolution.
- Stochastic Effects. Health effects of radiation exposure that occur by chance and increase in probability with higher doses, such as cancer and genetic mutations.
- Survey Meter. A portable instrument used to measure radiation dose rates or contamination levels in an environment, providing crucial data for safety assessments.
T
- Thermoluminescent Dosimeter (TLD). A device that measures cumulative radiation exposure by trapping electrons in a crystalline material and releasing them as light when heated.
- Time, Distance, and Shielding Principles. Core methods for radiation protection, emphasizing reduced time spent near sources, increased distance, and effective shielding to minimize exposure.
U
- Ultrasoft X-Rays. Low-energy X-rays with limited penetration power, typically used in specialized imaging techniques or experimental research.
- Unsealed Radioactive Source. A radioactive material not encapsulated in a protective container, often used in nuclear medicine and research, requiring stringent safety protocols.
V
- Virtual Dose. A theoretical measure used in computer simulations and modeling to estimate radiation exposure in hypothetical scenarios.
- Volumetric Modulated Arc Therapy (VMAT). An advanced form of radiation therapy that delivers precise doses of radiation while rotating around the patient, minimizing damage to healthy tissues.
W
- Whole-Body Counter. A specialized device used to measure radioactive materials inside the human body by detecting gamma rays emitted from within.
X
- X-Ray Radiation. A form of electromagnetic ionizing radiation used in medical imaging and diagnostics, requiring strict exposure control to protect patients and healthcare workers.
Y
- Yield (Radiation Yield). The efficiency or proportion of energy from a radioactive decay or interaction process that is emitted as a particular type of radiation, such as gamma rays or neutrons.