CH1&2 Flashcards
What are X rays?
A form of ionizing radiation.
Consequences of Ionization in Human Cells?
Creation of unstable atoms. Production of free electrons. Production of low-energy x-ray photons. Creation of reactive free radicals capable of producing substances poisonous to the cell. Creation of new biological molecules detrimental to the living cell. Injury to the cell that may manifest itself as abnormal function or loss of function.
How can we safely use radiant energy?
Employ effective methods to eliminate hazards. For instance Cardinal Rules ALARA
Saftey Control of Radiant Energy is done by
1)Control Radiation produced 2) ensure radiation safety 3) Limiting the energy deposited in living tissue
Effective Radiation Protection
On going responsibilities of diagnostic imaging professionals to ensure radiation safety during all medical radiation procedures.
Effectiive measures are employed by radiation workers to:
Safeguard patients, personel, and general public
Unecessary radiation is considered
Any radiation that does not benefit the patient in terms of diagnostic information obtained for clinical management of medical needs
Benefit vs Risk
Patient can elect to assume relatively small risk of exposure to ionizing radiation, to obtain essential information when illness or injury occurs.
Diagnostic Efficacy
Degree to which diagnostic study accurately reveals the presence or absence of disease in the patient.
Diagnostic Efficacy is maximized when?
when essential images are produced under recommened radiation protection guidelines
Achievement of diagnostic starts and ends at?
Procedure justified by physician, min radiation exposure, optimal images produced, disease present of absent=Diagnostic Efficacy
The goal is to produce optimal images in what exposure?
The first
ALARA is synonymous with which term?
Optimization for Radiation Protection (ORP)
Educating patients about imaging procedures helps:
To ensure the highest quality of service
To keep radiation exposure and consequent dose to the lowest possible level:
ALARA
Patient education entails:
Use of appropriate and effective communitcation, answer q’s honestly, inform pt’s of what needs to be done
Risk in general terms:
The probability of injury ailment or death resulting from an activity
Risk in medical field:
The possibility of inducing a radiogenic cancer or genetic defect after radiation.
BERT
Background Equivalent Radiation Time
BERT does what?
Compares radiation received w/natural background radiation recived over a given period of time.
Bert reduces?
Patient fears and anxiety
Energy is
The ability to do work
How does radiation relate to energy?
Energy that passes from one location to another and can have many manifestations
What are the two types of radiation?
Mechanical and electromagnetic waves
Mechanical radiation is
Ultrasounds
Electromagnetic waves are
Radiowaves, Microwaves, Infrared, Visible light, UV, X-rays, and gamma rays.
Electromagnetic waves can be defined as
Electrical and Magnetic fields which fluctuate as they travel together through space.
Electromagnetic waves are characterized by their:
Frequency, Wavelength
Electromagnetic waves have a dual nature: (wave-particle duality)
This form of radiation can travel through space ini the form of a wave, but can interact with matter as a particle of energy.
Electromagnetic radiation can be divided into what two parts?
Ionizing and nonionizing
Ionizing radiations are:
UV (high energy), x-rays and gamma rays.
Nonionizing radiations are:
UV (low energy), visible light, infrared rays, microwaves and radiowaves.
Nonionizing does not have sufficient
Kinetic energy to eject electrons from atoms.
Ionization is
The conversion of atoms to ions.
Ionizing Radiation definition:
Any type of particle or electromagnetic wave that can ionize or remove electrons from atoms.
Particulate Radiation is the form of radiation that includes?
Alpha Particles, Beta, Neutrons and protons.
What kind of radiation posesses enough kinetic energy to cause ionization by direct atomic collision?
Particulate Radiation.
Alpha particles are emitted from?
Nuclei of very heavy elements, such as uranium and plutonium during radioactive decay.
Particle that has large mass and positive charge twice that of an electron.
Alpha Particles. (2+)
Beta particles are ___ penetrating than alpha.
More
Particles that lose energy quickly?
Alpha, can be stopped by paper.
Alpha particles are dangerous as:
an internal source of radiation, through inhalation.
Beta particles:
Are identical to high speed electrons except their origin and 8,000 times lighter than alpha.
High speed electrons that arent beta are created in what machine?
Linear accelerator (used in radiation oncology) .
Protons charge in atom nucleus?
(+1)
Protons mass?
2800 times larger than an electron.
Neutrons are electrically?
Neutral, and approximately the same size as a proton.
Skin entrance dose (SED) is also known as?
Skin entrance exposure (SEE)
Skin entrance dose (SED) means that:
The skin entance point is going to have the highest numerical dose but a lower biological response.
Equivalent Dose (EqD)
a quantity, when a person recieves exposure from various types of ionizing radiations.
EqD attempts to:
Numerically specify the differences in biological harm that are produced by different types of radiation.
In order to calculate EfD we need
the EqD
EqD SI unit and traditional:
Sievert (Sv) and rem. 1 sievert=100 rem
Effective does (EfD) takes in to account:
the dose for all types of ionizing radiation to irradiated organs or tissues in the human body.
In order to get an EfD this information is needed:
1)Type of radiation 2)Type of tissue 3)Associate certain biological effects
Biological damage can come in two forms:
1)Genetic (affecting offspring) 2)Somatic (affects self)
1I sievert is the equivalent to how many rem?
100 rem
Sources of ionizing radiation that humans are exposed to are:
Natural (Background), and Manmade (artificial)
Types of natural radiation are:
Terrestial, Cosmic (solar and galactic), internal radiation from radionuclides
Man made (artificial radiation) Comes from?
air travel, nuclear fuel for power, nuclear weapons atomospheric fallout, nuclear power plant accidents, Medical radiation.
Medical radiation exposure comes from?
the use of x ray machines, and radiopharmaceuticals in medicine.
The two largest sources of artificial radiation are?
Diagnostic medical x rays and nuclear medicine procedures.
Variability in patient dose for imaging procedures are caused by:
1)Xray equipment variability 2)imaging procedure differences 3)radiologist differences 4)diff in techniques 5)facility providing services
Amount of radiation received by a patient is indicated in:
1)ESE and Glandular Dose 2)Bone Marrow Dose 3)Gonadal Dose
In pregnant woman what type of dose might be estimated?
Fetal dose
NCRP stansd for?
National Council on Radiation Protection
The number of medical procedures involving radiation has inc since?
the 1980s
Medical x rays make up howmuch % of total background radiation?
48%
Increase in medical radiation exposures are due to:
CT
New total annual background radiation per person is:
6.25 mSv
