Radiation Protection in Medical Radiography

These flashcards cover essential topics in Radiation Protection in Medical Radiography, focusing on biological effects, radiation types, safety protocols, and key terms relevant to the field.

What is the basic unit for all living things?

The cell.

What is homeostasis?

The ability to function in a normal manner despite changes in the body.

What does exposure to ionizing radiation do to cells?

It damages components, causing abnormal behavior or cell death.

What are organic compounds?

Compounds that contain carbon, including proteins, carbohydrates, lipids, and nucleic acids.

What is protoplasm?

The chemical building material for all living things.

What is the typical percentage of water in protoplasm?

Approximately 80%.

How do proteins function in cells?

They support growth, tissue construction, and repair of injured tissue.

What are amino acids made of?

NH2 (Amine) and COOH (Carboxylic Acid).

What is the primary function of carbohydrates in cells?

To provide energy and fuel for cell metabolism.

What are the types of carbohydrates?

Monosaccharides, disaccharides, and polysaccharides.

What is the structure of DNA?

A double-helix composed of sugar-phosphate chains and nitrogenous bases.

Which nitrogenous base binds with adenine in DNA?

Thymine.

What is direct action in radiation interaction?

Interaction occurs directly with essential molecules.

What is the primary concern with high LET radiation?

It can cause multiple strand breaks in DNA, which are often not repairable.

What is Relative Biological Effectiveness (RBE)?

The relative capability of radiation with differing LETs to produce a biologic reaction.

What happens in radiolysis of water?

Ionization of water molecules can produce free radicals that may be harmful to cells.

What is apoptosis?

Programmed cell death.

What are somatic effects?

Effects of radiation that occur in non-reproductive cells.

What is Acute Radiation Syndrome (ARS)?

A syndrome occurring after whole-body exposure to large doses of radiation.

What is the average annual radiation dose per person in the US?

6.2 mSv.

What effect does radiation have on blood cells?

It can lead to hematologic depression, decreasing RBC, WBC, and platelets.

What are the phases of the cell cycle?

G1, S phase, G2, and Mitosis.

What phase of the cell cycle is the most sensitive to radiation?

G2 and M phase.

What does a cell undergo during mitosis?

Division to form two identical daughter cells.

What are the four subphases of mitosis?

Prophase, Metaphase, Anaphase, Telophase.

What distinguishes meiosis from mitosis?

Meiosis reduces the chromosome number by half for reproduction.

What are monozygotic twins?

Identical twins formed from a single fertilized zygote.

What is the definition of stochastic effects?

Effects that occur by chance and do not have a threshold.

What is a deterministic effect?

An effect that has a threshold and severity is dose-related.

What is the significance of the dose-response curve?

It helps understand the relationship between radiation dose and biological effects.

What is the therapeutic range for ionizing radiation?

It is the range where beneficial effects occur without excessive risk.

What is the role of repair enzymes?

To mend damaged DNA molecules after radiation exposure.

What is a lethal dose (LD50/30)?

The dose that results in the death of 50% of the population within 30 days.

What is Bergonie and Tribondeau's law?

Radiosensitivity of cells is directly proportional to their reproductive activity and inversely proportional to their degree of differentiation.

What cell type is most radiosensitive?

Lymphocytes.

What are early effects of radiation?

Effects that appear soon after exposure to large doses.

What are late effects of radiation?

Effects that manifest months or years after exposure.

What is the Oxygen Enhancement Ratio (OER)?

The ratio of radiation dose required to cause a biological response in hypoxic vs. normoxic conditions.

What is significant about cataractogenesis in radiation exposure?

The probability of cataract formation increases with radiation dose.

What differentiates somatic and genetic effects?

Somatic effects affect the individual while genetic effects can affect future generations.

What is the influence of tissue weighting factors?

They account for the varying sensitivity of different tissues to radiation.

What is the role of regulatory agencies in radiation safety?

To set guidelines and limits for radiation exposure.

What is the main principle of ALARA?

To keep radiation exposure As Low As Reasonably Achievable.

What kind of radiation is most harmful internally?

High LET radiation such as alpha particles.

How can one reduce radiation exposure during diagnostic imaging?

By using collimation, shielding, and optimizing technical factors.

What does a film badge measure?

Occupational radiation exposure.

What type of shielding is recommended for personnel handling radiopharmaceuticals?

Lead or equivalent shielding.

What is dose creep?

The practice of lax technique leading to increased exposure.

What is a secondary barrier?

A barrier used to protect from scatter radiation.

What does cumulative effective dose (CumEfD) represent?

Lifetime exposure limit based on age and occupational history.

What is meant by the term 'biological effects of radiation'?

The responses of living organisms to ionizing radiation exposure.

What is the function of a Radiation Safety Officer (RSO)?

To oversee radiation safety programs and ensure compliance with regulations.

What are the key factors for radiation dose management?

Time, distance, and shielding.

What is meant by equivalent dose (EqD)?

A measurement that reflects the biological impact of different types of radiation.

What can high doses of radiation lead to?

Acute Radiation Syndrome and potential death.

How do modern fluoroscopy units minimize dose?

Through pulsing technology and ‘last image hold’ features.

What is the purpose of an exposure timer in radiology?

To manage the duration of x-ray exposure.

What is the emergency dose limit for personnel engaged in lifesaving activities?

250 mSv per incident.

What is a bucky slot cover?

A protective device that covers the opening in the x-ray table during fluoroscopy.

How do radiologists ensure labeling clarity for radiation areas?

By using clear warning indicators and signage.

What is significant about embryologic effects of radiation?

They vary depending on the stage of development and exposure dose.

What are intragenic responses broken down into?

Early and late reactions.

What does 'restitution' mean in the context of radiation damage?

The repair process where breaks in DNA rejoin without visible damage.

Name an example of early tissue damage caused by radiation.

Erythema or skin redness.

What is the genetic dose limit for a developing fetus?

0.5 mSv per month.

What is the cumulative lifetime effective dose limit for radiation workers based on age?

10 mSv multiplied by age in years.

Describe a polarized viewpoint in radiation exposure standards.

Conservative organizations tend to overestimate risks rather than underestimate them.

What common clinic exposure can patients frequently experience?

Diagnostic radiology procedures with minimal risk.

What is a primary barrier?

A barrier that protects against direct radiation exposure.

What measures are taken to ensure safe handling of radioactive materials?

Wearing dosimeters and using containment protocols.

What are two types of radon exposure?

Background and occupational exposure.

What is significant about genetic mutations in relation to radiation?

They can result from spontaneous changes and ionizing radiation exposure.

What is the main consideration during pregnancy and diagnostic imaging?

To minimize radiation exposure.

Identify a type of low LET radiation.

X-rays.

What is the role of hydraulic barriers?

To protect personnel from radiation scatter.

What kind of radioactive element is Technetium-99m?

A commonly used radioisotope in nuclear medicine.

What happens during the gastrointestinal syndrome from high radiation doses?

Severe nausea, diarrhea, and potential death in 3-10 days.

What is a common cause of radiation-induced cancer?

Exposure to high levels of ionizing radiation.

In what instances does the use of oxeninduction happen?

In radiation therapy and other medical radiology applications.

What was the threshold for health risks in historical nuclear accidents?

Exposure levels significantly above background radiation.

What conclusion might be drawn from studies of atomic bomb survivors?

Long-term cancer risks arise from acute radiation exposure.