radi 442 test 3 (noble course segment)

protons (+ charge, determines atomic # and element, inside the nucleus), neutrons (no charge, inside the nucleus), electrons (- charge, in valence shells, binding energy holds them in place, eV or keV electron volts where 1,000 eV = 1 keV)

atomic structure

radiation

energy; in our world, we equate it to x-rays

ionization

removal of an electron; losing an e- leaves you with an ion pair

ionizing radiation

radiation capable of removing electrons; x-rays have the ability to ionize atoms/knock out e-, causing biological impact from disrupting atoms

neutral elements have an equal amount of protons and electrons, so losing an electron induces a positive charge

how do neutral elements get ionized?

x-ray photon causes an electron to get ejected from orbit so the atom is left with a hole; the atom is no longer neutral, causing a biological impact

explain ionization

radiation protection

measures taken to protect patients, employees, and the public from unnecessary exposure to ionizing radiation

x-ray rooms/suites are designed with radiation protection in mind, so when you swap out equipment, you have to make sure the x-ray room can handle the unit being put in place; costs a lot of money

how are x-ray rooms designed with radiation protection in mind?

PREVENT tissue reactions and MINIMIZE risk of stochastic effects

what are the goals of radiation protection?

biological impact

ionized atoms cause…

we know exactly how much exposure it takes to cause different types of tissue reactions

why can we PREVENT tissue reactions from radiation?

we don’t know what the dose is or what exactly causes these effects

why can we only MINIMIZE the risk of stochastic effects and not prevent them?

example of a tissue reaction

example of a stochastic effect

cancer

as low as reasonably achievable (exposures should be made with the least amount of radiation as possible)

occupational radiation protection concept; ALARA

optimization for radiation protection; same idea as ALARA, keep radiation doses to the minimum necessary to achieve the required image

occupational radiation protection concept; ORP

time, distance, shielding

what are the cardinal principles (rules)?

minimize time exposed to radiation, time in the x-ray room, etc.

explain the time cardinal principle

maximize distance from radiation

explain the distance cardinal principle

utilize shielding, protect yourself with protective wear and barriers

explain the shielding cardinal principle

weigh the risk vs. the benefit of the exam; this does NOT fall on the technologist, it is up to the ordering physician to decide how the risk of radiation compares to the benefit of the scan

patient radiation protection concept; justification

is this the appropriate procedure for the suspected condition or disease? also falls on the ordering physician’s shoulders

patient radiation protection concept; diagnostic efficacy

provided by the ACR (american college of radiology); evidence-based guidelines for selecting appropriate imaging procedures; based on patient condition

patient radiation protection concept; appropriateness criteria

time, distance, and shielding in regards to the patient; the cardinal principles apply to occupational workers (techs) AND patients

patient radiation protection concept; cardinal principles (rules)

background equivalent radiation time; risk perspective; puts patient radiation exposure into perspective

what’s the purpose of the BERT method?

BERT = background equivalent radiation time; compares radiation received by the patient to natural background radiation (which is about 3 mSv/year); emphasizes that radiation is part of our daily lives; does NOT imply risk, it is only a comparison; makes it easier for patients to understand their radiation exposure; just helps the patient understand, not tying a specific risk to the exam

explain the BERT method

3 mSv per year

what is the natural background radiation amount?

normal x-rays involve taking only 2-3 images, whereas CT involves longer exposure and more images

why does it make sense that x-rays have a lower approximate effective radiation dose compared to CT?

less than 3 hours (< 0.001 mSv)

how does extremity x-ray compare to natural background radiation?

6 months (1.4 mSv)

how does lumbar spine x-ray compare to natural background radiation?

10 days (0.1 mSv)

how does chest x-ray compare to natural background radiation?

2 years (6.1 mSv)

how does chest CT compare to natural background radiation?

2 years (6 mSv)

how does barium study (fluoroscopy, BE or UGI) compare to natural background radiation?

2.6 years (7.7 mSv)

how does abdomen & pelvis CT compare to natural background radiation?

DON’T; their bodies are more sensitive

peds (do/don’t) require the same amount of radiation exposure for an exam as adults do

image gently

what is the radiation protection campaign for pediatrics?

to change practice by raising awareness of the opportunities to lower radiation dose in the imaging of children

what is the goal of image gently?

started with CT, expanded to include fluoroscopy, interventional, nuclear medicine, digital imaging, dentistry

what is the focus of image gently?

provide information and free educational materials for medical professionals and parents

what is the strategy of image gently?

image wisely

what is the radiation protection campaign for older adults?

lower radiation dose in adults

what is the goal of image wisely?

provide resources for medical professionals and patients

what is the strategy of image wisely?

NEXT = nationwide evaluation of x-ray trends; fed. gov. agencies worked with state departments to collect dose information and establish dose reference levels (DRLs)

explain the radiation protection initiative - NEXT program

dose reference levels were brought about because of digital imaging and exposure; the NEXT program set the foundation for exam dose awareness; “for each exam, try for this target exposure level”; provided guidelines to help institutions adjust their exposures

explain DRLs and how they came about

there is a built-in system that tracks dose information and this information is saved and can become part of a patient’s medical record

explain digital imaging systems dose tracking software

requires patient dose monitoring - CT and fluoroscopic procedures have built-in monitoring; they have to have the software that traces patient exposure to radiation

to maintain accreditation status, the joint commission (TJC)…

annual education for staff that focuses on dose reduction, minimum qualifications for medical physicists, documentation of CT doses, mandated standardized CT protocols; the goal is always to be aware and minimize patient exposure to radiation!

what are the additional CT requirements for dose monitoring, as required by TJC?

dose alert protocols

how do we handle situations where patients are overexposed or if there’s a risk of overexposure?

protocols for handling situations where patient doses are expected to exceed or have exceeded normal levels; radiographers and/or radiologist assistants may need to provide information to the medical physicist or radiologist for dose calculation; you may have to proceed; examples include pregnancy status, patient size, areas irradiated, technical factors, and dose data from imaging system

what are dose alert protocols?

the ability of machines or computer systems to learn, reason, make decisions, recognize patterns, and solve problems in ways that mimic or augment human cognitive abilities

what is artificial intelligence (AI)?

dose optimization, exposure settings, image processing, image interpretation (radiologist side of things); a lot of systems and equipment in the hospital incorporate AI; exposure settings can be given by AI after analyzing pt parameters and clinical implications, but you still need to think and know what’s correct because AI is not 100% accurate

how does AI play a role in medical imaging?

focuses on peds and ensures vendor software works for pediatric pts; promotes safe AI for pediatrics; AI systems must be specifically designed for peds and there must be standardized labeling for FDA-cleared medical devices that use AI for peds; the devices must clearly indicate that they’re safe and reliable for peds; remember that peds are different from adults so AI needs to be developed specifically for them; AI that uses adult data will not be accurate for peds, so models need to be based on peds

what does the image intelliGently campaign do?

energy

radiation is __

all types of radiation, different types of energy (because radiation is energy)

mechanical, thermal, chemical, electrical, sound, nuclear, electromagnetic (x-rays!)

radioactive decay

alpha particles are a product of __

the nucleus of an atom

where does radioactive decay occur?

unstable nuclei release charged particles to restabilize itself

why does radioactive decay occur?

uranium and radon (naturally occurring elements)

alpha particles are emitted from __

radioactive decay

beta particles are a product of __

iodine-131 (which is a radioisotope/unstable form of iodine)

beta particles are emitted from __

electromagnetic (EM) radiation; electric and magnetic properties

x-rays are an example of __

meters (m)

wavelength is measured in __

hertz (Hz)

frequency (f) is measured in __

frequency x wavelength

speed of light (c ) = ?

electron volts (eV)

energy (E) is measured in __

direct

wavelength and energy have a __ relationship

decreases

wavelength __ as you move to the right on the EM visible spectrum

increases

frequency __ as you move to the right on the EM visible spectrum

indirect/inverse

wavelength and frequency have a __ relationship

increases, direct

as frequency increases, energy __ because of the __ relationship between frequency and energy

lower

longer wavelength correlates with __ frequency

higher

shorter wavelength correlates with __ frequency

shorter, higher

x-rays have __ wavelength and __ frequency compared to visible light

the speed of light

radiowaves, microwaves, visible light, etc. all travel at __

x-rays have shorter wavelength, thus higher frequency, thus higher energy than visible light and are energetic enough to get into the body and cause ionization/disrupt atomic structure

why does the wavelength and frequency of x-rays matter?

electrical and magnetic disturbances traveling in space, no mass and no charge (they’re neutral and not a quantity of matter), can’t focus with a lens or be redirected, travel in straight lines in a vacuum (x-ray tube) at the speed of light (in a wave form/pattern but travels straight towards the patient), shorter wavelength and higher frequency means energy increases, interact with matter and ionize because they have high enough energy, exhibit wave and particle behavior (wave-particle duality)

list the properties of x-rays

bundle of energy (photon or quantum) traveling through space along a straight path but in an x-ray waveform; like a wave pattern as if it were contained in a particle/ball as a bundle of energy

explain wave-particle duality

the amount of energy deposited/transferred along the path of travel; how much energy is given up by a photon along its path of travel

what is linear energy transfer (LET) ?

high

low penetrability = __ LET

the photon gives up all of its energy very readily; like a sprinter

what does a high LET mean?

low

high penetrability = __ LET

the photon gives up its energy over a longer period of time; like a marathon runner

what does a low LET mean?

high, low

alpha (uranium, radon) has __ LET meaning __ penetrability

high

because alpha is __ LET, it can be stopped by the skin

low, high

beta and x-rays are __ LET meaning __ penetrability

no, it just means you’re getting all the radiation at one spot

does alpha particles being high LET make them safe?

low

because beta is __ LET, it penetrates through the body but can be stopped by an aluminum sheet

the lowest

because x-rays are __ LET, they penetrate through the body and aluminum, needs lead to fully stop

alpha, x-rays

__ is the highest LET and __ is the lowest LET

on the electromagnetic (EM) spectrum

both non-ionizing and ionizing radiation are __

non-ionizing radiation

long wavelengths, short frequencies, low energy; not enough energy to ionize atoms

ionizing radiation

shorter wavelengths, higher frequencies, higher energy; enough energy to ionize atoms

non-ionizing

radio waves are __ radiation

non-ionizing

microwaves are __ radiation

non-ionizing

infrared light is __ radiation

non-ionizing

visible light is __ radiation

some is non-ionizing, some is ionizing, that’s why it’s important to protect yourself from the sun

ultraviolet (UV) light is __ radiation

vibrate or heat atoms

what is the result of non-ionizing radiation?

ionizing

x-rays (manmade) are __ radiation

ionizing

gamma rays (nucleus of atom, last on EMS) are __ radiation