Radiation Safety in Medical Imaging

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Questions and Answers

What should be used on patients of childbearing age or younger during specific exams?

Protective gloves only

Gonadal shields (correct)

Lead aprons only

Protective goggles and gloves

What is the primary focus when conducting exams on pregnant patients during the first trimester?

To prioritize the use of protective devices

To use only minimal radiation

To conduct as many exams as possible

To limit exams on the pelvis and lower abdomen (correct)

What is the correct action regarding beam collimation during examinations?

Always collimate to the smallest appropriate field size (correct)

Collimate based on the patient's request

Collimate only when necessary

Use the largest possible field size for better accuracy

What is meant by 'Dose-Rate' in radiation terminology?

The amount of radiation per unit time Signup and view all the answers

What does 'kVp' stand for in radiological terms?

Kilovolt peak Signup and view all the answers

What key principle is associated with maintaining radiation exposure at minimal levels during medical procedures?

ALARA Principle Signup and view all the answers

Which of the following tissues is classified as radiosensitive in adults?

Gonads Signup and view all the answers

What is the primary science that studies the effects of radiation on living organisms?

Radiobiology Signup and view all the answers

Which type of radiation is described as having enough energy to ionize atoms?

X-ray radiation Signup and view all the answers

What are examples of radioresistant tissues in adults?

Fat and central nervous system Signup and view all the answers

What does the acronym ALADA stand for?

As Low As Diagnostically Achievable Signup and view all the answers

Which type of tissues are typically less affected by radiation exposure?

Bones Signup and view all the answers

Which human tissues are more radiosensitive?

Fetuses Signup and view all the answers

Which term refers to radiation effects that result with certainty?

Deterministic effects Signup and view all the answers

Which organs or areas should be shielded during radiation procedures?

Critical organs only Signup and view all the answers

What is a potential stochastic effect of radiation exposure?

Increased cancer risk Signup and view all the answers

What is the primary function of collimators in radiation protection?

To limit the beam size Signup and view all the answers

How does increasing the kVp while decreasing the mAs contribute to dose reduction?

It reduces exposure time without increasing dose. Signup and view all the answers

Which of the following is NOT a type of protective lead clothing?

Lead glasses Signup and view all the answers

Which device is effective for immobilizing patients during x-ray procedures?

Sandbags Signup and view all the answers

What is the annual dose limit for the general public according to radiation exposure limits?

1 mSv Signup and view all the answers

What is the radiation detection material used in an Optically Stimulated Luminescent (OSL) dosimeter?

Aluminum oxide Signup and view all the answers

Which statement about filters in beam modifying devices is accurate?

They help reduce radiation dose to the patient's skin. Signup and view all the answers

What is the recommended limit for radiation exposure to the lens of the eye for radiation workers?

20 mSv Signup and view all the answers

Which of the following combinations of technical factors is recommended for reducing radiation exposure?

Increase kVp and decrease mAs Signup and view all the answers

What does the intensity of visible light emission from Al2O3 relate to?

The radiation dose received Signup and view all the answers

Which statement about the OSL dosimeter is false?

It can be stored in any location Signup and view all the answers

Where should an OSL dosimeter be worn?

Between the shoulders and waist over clothing Signup and view all the answers

What is one of the advantages of the OSL dosimeter over the TLD?

More accurate and more sensitive Signup and view all the answers

What should not be done according to the Ten Commandments of Radiation Protection?

Stand in the primary beam during operations Signup and view all the answers

What is required every 3 months for exposure reports?

Dosimetry Services report Signup and view all the answers

What is a key characteristic of OSL dosimeters?

They have a wide dynamic range Signup and view all the answers

What year was the Society of Radiological Technologist established

1920 Signup and view all the answers

What year was the first MRI image made

1977 Signup and view all the answers

What are the three cardinal principles

↓time, ↑distance and ↑ shielding Signup and view all the answers

TLD stands for "thermoluminescent dosimeter"

True Signup and view all the answers

ICRP fundamental principles are; limitations. optimization and respect

False Signup and view all the answers

OSL stands for "optical sensitive luminescent"

False Signup and view all the answers

Study Notes

Lecture 2: Radiation Protection

Topic: Radiation Protection overview
Learning Outcome: Identify radiation safety practices and apply them in the lab and clinical settings.
Ministerial Competencies: Analyze parameters influencing person exposure, prevent risks from ionizing radiation and radio frequency waves, recognize organizations regulating protection.
Objectives:
- Identify the importance of technical parameters for radiation protection.
- Describe the ALARA/ALADA principles.
- Recognize methods technologists use to protect themselves and the public from radiation.
- Describe the principle of personnel dosimetry and proper dosimeter use.
- Define organizations regulating radiation protection.
Radiation is all around us in different forms.
Radiation is energy that travels through space, such as light or heat.
X-rays are a form of radiant energy like light or radio waves, but they are ionizing and can penetrate the body, enabling internal body structure imaging.
Radiation Oncology (RO) and Nuclear Medicine (NM) use radioactive sources for treatment and imaging.

What is Radiation?

Radiation is any energy that comes from a source and travels through space, such as light or heat.
X-rays are a form of radiant energy, like light or radio waves, unlike light, X-rays are ionizing radiation that can penetrate the body and produce images of internal body structures.

Discovering the Inside Story: Innovations in Medical Imaging and Radiation Therapy

Wilhelm Conrad Röntgen discovered X-rays in 1895.
First clinical use of X-rays by physicians was in 1896.
X-ray use for cancer treatment began in 1903.
William Coolidge invented the heated cathode X-ray tube in 1913.
Marie Curie designed X-ray vehicles for World War I.
Development of the CT scan in 1971
Invention of the MRI in 1977

Radiation Protection

Protecting against radiation is necessary due to the harmful effects of radiation exposure.
The effects of radiation exposure worsen with higher exposures
Radiation protection involves measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation.
The goal is to keep radiation exposure as low as possible (ALARA is the goal and ALADA is the principle).

3 Cardinal Principles of Radiation Protection

Time: Keep exposure time to a minimum.
Distance: Move as far away from the radiation source as possible.
Shielding: Use protective barriers and clothing.

Radiography and Radio scopy

Radiography uses X-rays to obtain static images of body structures.
Radio scopy uses X-rays to allow real-time visualization of body structures during fluoroscopy.

Inverse Square Law (ISL)

The intensity of radiation passing through a unit area is inversely proportional to the square of the distance from the radiation source.
The further you are from the source, the less exposure you will receive.
If the source is twice as far away, the radiation exposure is only a quarter as much.

Shielding in Radiology

Physical barriers are used to block radiation.
Lead walls and windows are used to block radiation.
Technologists/professionals must wear lead aprons, gloves, glasses, and other protective gear. The types of shielding materials are important to use depending on the energy of the radiation, for example, 2-3 foot concrete walls for very high energy radiation/machines.

Personnel Dosimetry

Optically Stimulated Luminescent (OSL) and Thermoluminescent (TLD) dosimeters are used to measure radiation exposure.
OSL dosimeters use aluminum oxide coated with carbon to measure and detect radiation.
TLD dosimeters use lithium fluoride crystals.
OSL dosimeters are highly sensitive and accurate, along with a wide dynamic range and excellent long-term storage. A minimum reportable dose for OSL devices means they are sensitive enough to detect a minimum radiation dose.

Radiation Protection Organizations

Provincial: OTIMROEPMQ (standards of Practice), MSSS (Ministère de la Santé et des Services sociaux), and CECR (Centres of Excellence for Commercialization and Research program).
Federal: CAMRT (Canadian Association of Medical Radiation Technologists), CCRPB (Consumer and Clinical Radiation Protection Bureau), CNSC (Canadian Nuclear Safety Commission), and SC35 (Safety Code 35 Guidelines and Recommendations).
International: ICRP (International Commission on Radiological Protection).

The Ten Commandments of Radiation Protection

Understand and apply the cardinal principles of radiation control.
Do not allow familiarity to result in false security.
Never stand in the primary beam.
Always wear protective apparel.
Do not hold patients unless necessary.
The person holding the patient must wear a protective apron.
Use gonadal shields when needed.
Avoid unnecessary exams on pregnant patients.
Always collimate to the smallest field size.

Student Pregnancy Policy

The student is responsible for informing the program coordinator (PC) if pregnancy is suspected or confirmed.
Students might be permitted to continue the program during the first two years, but may be required to interrupt clinical training during the third year.
The student will receive a second dosimeter for closer fetal monitoring.

Radiobiology

Radiobiology evaluates the effects of radiation on biological tissues and living organisms.
Radiation physics and biology are critical elements of radiobiology.
X-ray radiation is ionizing.
Ionizing radiation deposits energy at the atomic level.

Radiosensitive vs. Radioresistant Human Tissues

Radiosensitive tissues in adults include gonads, blood-forming organs (bone marrow), and blood.
Radioresistant tissues in adults include bone and fat.
Fetus tissues are more radiosensitive than adult tissues.

Benefits

Explain how radiation is used for diagnosis and treatments.

Risks

Deterministic effects are radiation effects that happen with certain doses and are dependent on the amount of radiation dose; an example is a severe sun burn.
Stochastic effects are the probability/risk of harm from radiation, such as cancer.

Optimization in Radiation

To create high quality imaging/treatment plan, using necessary and appropriate radiation doses.
- the ALARA principle (minimizing radiation exposure as low as reasonably achievable)
- and ALADA principle (minimizing exposure as low as diagnostically acceptable).
Ways to optimise radiation exposure are: using proper technical factors or reducing the exposure time, shielding critical organs, treating using multiple planes during treatment (for RO), decreasing half-life duration of radiation sources (for NM).

Radiation Exposure Limits

Dose limits for radiation workers and the general public, and patient dose limits.
Diagnostic reference levels (DRLs) for various medical examinations.

Radiation Protection Devices

Protective structural shielding (lead, concrete)
Protective lead clothing (aprons, gloves, glasses, gonadal/thyroid shields)
Beam Limiting devices (collimator, lead strips)
Beam Modifying devices (filters)

Other Factors that Contribute to Dose Reduction

Proper selection of technical factors
Use of immobilization devices
High-performing devices and effective processing techniques.

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Description

This quiz addresses essential knowledge regarding radiation safety practices, specifically focusing on examinations related to patients of childbearing age, pregnant patients, and principles governing minimal radiation exposure. It also covers the understanding of various types of tissues in relation to radiosensitivity and the ALARA principle.