Rad Bio/ Radiation Protection Ch. 1/2/3

List two things the R.T can do before bringing the patient in the room to ensure good radiation protection practices

• properly ID the patient

• check the dr.’s orders

• lay out the lead shield so it’s not forgotten

List three things the R.T. can do while the patient is in the room to ensure good radiation protection practices for the patient

• Collimate

• Use lead shielding

• minimize repeats (get it right the first time!)

• Use high kVp/ low mAs when possible

• take an accurate hx (make sure the hx matches the exam) 

• follow protocol (don’t take extra images unless necessary)

List two things the R.T. can do while the patient is in the room to ensure good radiation protection for themselves

• wear a dosimeter

• increase their distance from the x-ray source

• limit the time spent in the room during the exposure

• wear lead shielding when in the exam room

• minimize repeats

• do not hold the patient

• stay behind the control panel barrier when exposing

List three possibilities that an x-ray photon can undergo when it interacts with matter

• Complete penetration without interaction

• Complete absorption (photoelectric interaction)

• Scattering (Compton or classical interaction)

List two forms of inherent filtration

• Glass in the tube

• oil around the tube

List the two by products of the compton interaction

Recoil electron and compton scattered photon

Coherent scattering

occurs when a low energy photon interacts with an atom but doesn’t ionize it. The electrons are raised to a higher energy and thus vibrate. As the electrons settle back to their appropriate binding energies, a secondary photon is released with an energy that equals that of the incoming photon

Photoelectric interaction

occurs when an incoming photon possesses just enough energy to ionize the inner shell of the atom with which it interacts. The incoming photon uses all of its energy in the ionization process and is thus completely absorbed

Compton Scattering

occurs when an incoming x-ray photon interacts with an outer shell electron and ionizes the atom. Thus, part of the energy of the incident photon is absorbed and part of it is released as a secondary photon, usually traveling in a different direction than the incident photon and with less energy

Characteristic radiation

occurs when an electron from an outer shell drops to fill a vacancy in an inner shell

Auger effect

occurs in place of characteristic radiation emission. Instead, the energy left over after the outer shell electron fills the vacancy in the inner shell is transferred to another electron of a nearby atom, thus ejecting the electron

If an RT attempts to explain the dose, a patient will receive during an x ray procedure by comparing it to background dose. What statistics are they quoting?

BERT

diagnostic _______ is the degree to which the diagnostic study accurately reveals the presence or absence of disease in the patient.

Efficacy

radiation protection may be defined as effective measures employed by radiation workers to protect patients, personnel, and the general public from _______ exposure to ionizing radiation

Unnecessary

an atom , which has been ionized by the addition of an electron, is what kind of ion.

Negative ion

when we remove an electron from an atom, what kind of ion is that?

Positive ion

X rays can cause biological damage due to their ability to what?

Ionization

What kind of radiation comes from radioactive material in the Earth?

Terrestrial

What are the types of background radiation?

• terrestrial

• Cosmic

• Internal

What is extra terrestrial in origin and results from nuclear interactions that take place in the sun and other stars. What's that?

Cosmic

what radiation exists in the tissues of the human body as a result of ingestion or inhalation of radiation particles?

Internal

what is man made radiation?

X-rays

when X rays travel through space, they are described as of what?

A waveform

When x rays interact with matter, they are described as a _____ form. This phenomenon is known as what? ______ duality

Particle; particle

What is the ability to do work or to move an object against resistance?

Energy

patients who are concerned about the radiation exposure, they might receive should receive which of the following explanations from their radiographer to alleviate their anxiety. What are some of the things you can tell them to relieve their anxiety in your own words? What are you gonna tell them?

• use Bert analogy

• benefits outweigh the risk

• X ray technology has advanced over the years and it takes much less a radiation today to create an image

what are the two largest sources of artificial ionizing radiation exposure in the US?

• X-rays

• Nuclear medicine radionuclides

the amount of radiation received by the patient can be measured how?

• entrance skin exposure

• Bone marrow dose

• Gonads

• Glandular dose

If we transfer all of the energy of the X ray photon to the atom and the patient, what is that term

Total absorption (photoelectric effect)

Which of the five interactions are of importance in diagnostic imaging?

• Photoelectric

• Compton

What is the reduction of the intensity of the primary beam?

Attenuation

what is the radiation called between the focal spot and the patient?

Primary

What is the sole purpose of filtration?

Reduce the low energy beam that would only serve to be absorbed in the first few centimeters of the skin, so ultimately, we're reducing patient dose

Where does X ray production occur?

The tube

what are the two types of x rays produced in the tube?

• bremsstrahlung

• Characteristic

what do we call the amount of energy absorbed per unit mass of tissue?

Absorbed dose

when a medical exam that uses ionizing radiation is ordered, the ______ should always outweigh the ______

Benefits; risks

Who is responsible for determining the medical necessity of a radiographic exam?

The ordering physician

What does the acronym ALARA stand for?

As low as reasonably achievable

X rays are a type of what kind of wave are they?

Electromagnetic

What is the distance between the crests an electromagnetic wave?

Wavelength

how many presss that pass a certain point?

Frequency

high frequency is what kind of wavelength?

Short

when a person receives a dose of ionizing radiation, that causes biological damage to them, it is termed a ____ effect.

Somatic

what was the average annual radiation equivalent dose per person in the U.S. from radon and thoron?

2.3 milliseiverts

What type of health risk exists with the exposure to radon?

Lung cancer

Who would receive the highest dose of cosmic radiation, a person in a flying jet or a person in a jet at the airport?

Flying jet

if you have a KVP setting of 75, what is the average photon energy in that beam going to be?

25 (1/3 that of peak)

the maximum energy of any photon in the beam will be how much?

75

What's your formula for mAs?

mA x time

time is measured in ________

Seconds

Which interaction causes no biological harm to patient?

Complete penetration without interaction

Which two interactions are useful in image production?

• photoelectric

• Complete penetration without interaction

how are X-rays produced?

When fast moving Electrons are stopped or slowed suddenly by the anode

x rays leave the tube through a thin portion of glass called the _________

Tube window

In the x ray tube, how much of the electron streams, kinetic energies converted to heat?

99.8%

The other point 2% is converted to what?

X-rays

What two things make up total filtration?

• inherent

• Added

Non interacting photons, are responsible for what shades of gray in the image?

Dark

photons that are completely absorbed are responsible for ____ shades of gray in the image.

Light

As KVP goes up, what interaction becomes the predominant interaction?

Compton

radiolucent structures are represented by what type of grey tones in the image?

Dark

radioppaque structures are represented by ______ gray tones in the image

Light

Why do we use contrast media? What does it do?

Enhances subject contrast

what type of contrast media creates more photoelectric interactions?

Positive contrast media because of high atomic number

positive contrast media creates more photoelectric interactions because of their high atomic number and that results in what kind of gray tones in the image?

Light

What type of contrast media work because of their low physical densities? result in what color gray tones in the image.

Negative contrast media; dark

Between positive contrast media and negative contrast media, which increases the patient's absorbed dose?

Positive

Give me an example of a positive contrast media

• barium

• Iodine

What's the atomic number of iodine?

53

Was the atomic number of barium?

56

what's an example of a negative contrast media?

• air

• Gas crystals

diagnostic efficacy

when essential images are produced under the recommended radiation protection guidelines

if we lower the dose to the patient, who else's dose will be lower?

Ours

if we adhere to ALARA, that will ensure what with your patient?

Minimal exposure to the patient.

Now, think of your patient when you tell them your doctor has considered the benefits of you having this exam outweigh the minimal risks involved. When you tell them that statement, most of the time, those patients are more likely to do what?

Assume the risk of having the x ray. They're more likely going to go along with it

what kind of wavelength is a very energetic x ray?

Short

what kind of frequency is a very energetic x ray?

High

Visible light compared to x ray. Tell me about the energy comparison between the two

visible light is gonna have less energy than an x ray photon

What chart would you look at to determine what's the most energetic?

Electromagnetic spectrum

mAs controls what?

Quantity

kVp controls what?

Quality

if we increase our absorbed dose, what happens to the risk of biological damage?

Increases

The material that is used in an construction must have what?

• high atomic number

• High melting point

your atomic number of tungsten?

74

your atomic number of rhenium?

75

your atomic number of molybdenum?

42

An X ray photon that passes through matter without any interaction, that is termed?

Direct transmission

an x ray, photon that has been scattered is termed?

Indirect transmission

As KVP goes up, the probability of a photoelectric interaction does what?

Decreases drastically

As KVP goes up, The probability of a compton interaction does what?

Decreases slightly

As the atomic number of a part goes up, the probability of a photolectric interaction does what?

Increases

As the atomic number of a part goes up the likelihood of a compton interaction does what?

Decreases

As the physical density of a part goes up, the probability of all interactions does what?

Increases

As the thickness of a part goes up, the probability of all interactions does what?

Increases

The classical coherent, unmodified Thompson, Rayleigh, elastic, is there a byproduct of that interaction?

No because they’re not ionizing

What is the byproduct of the photolectric interaction?

Photoelectron

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