Rad Bio Ch 1-3

define radiation protection

effective measures implemented by radiation workers to shelter patients, personnel, and general public from unnecessary ionizing radiation exposure

what term is used to express principle of keeping radiation exposure to a level that minimizes potential for adverse biologic damage to humans

ALARA (as low as reasonably achievable)

who should justify the need for every radiation procedure and accept basic responsibility for protecting the patient from nonuseful radiation exposure?

referring physician

the potential benefits of exposing patients to ionizing radiation should far outweigh any slight ___ of inducing a radiogenic malignancy or genetic defects

chance

what must imaging facilities have that provides for patient protection and patient education

radiation safety program

upon what is the need for safeguarding against unnecessary radiation exposure based?

evidence that ionizing radiation can cause adverse biological effects

one mSv is equal to

1/1000 of a Sv

what is the SI subunit for absorbed dose

mGy (milligray)

the degree to which the diagnostic study accurately reveals the presence or absence of disease in a patient, while adhering to radiation safety guidelines defines

diagnostic efficacy

any radiation exposure that does not benefit a person in terms of diagnostic information obtained from diagnostic images for the clinical management of medical needs is called

unnecessary radiation

what is the goal of modern radiation protection programs

protect from short and long term radiation effects

what is the most effective tool for diagnosing breast cancer early

high quality mammography

what is the name of the campaign that delivers the message that CT saves children’s lives but that patient dose should be lowered by child sizing the kV and mA settings, by scanning only the indicated anatomic area, and by removing multiphase scans from pediatric protocol

image gently

what method can a radiographer use to compare the amount of radiation received during a routine radiographing procedure with natural background radiation received over a specific period

BERT method

optimization for radiation protection is synonymous with the term

ALARA

the cardinal principles of radiation are

time, distance, and shielding

in a hospital setting, who does the administration charge to be directly responsible for the execution, enforcement, and maintenance of the ALARA program

radiation safety officer (RSO)

radiographers should select the ___ radiation exposure that will produce useful images and avoid errors that result in ___ radiographic exposures

smallest, repeat

BERT does not imply radiation risk; it is simply a means for

comparison

define radiation

movement of energy through space from one location to another

three electromagnetic radiations that are classified as ionizing radiation

x-rays, gamma rays, ultraviolet with energy greater than 10 eV

what is the most important process of the interactions of x-rays with human tissue

ionization

true or false: as an external source of radiation, alpha particles are more penetrating than beta particles

false

what radiation quantity is used to describe both occupational and nonoccupational dose limits, and what metric subunit is used

effective dose (EfD) in mSv

what does ionizing radiation produce that can cause biologic damage on the molecular, cellular, and organic levels in humans

electrically charged particles

smokers exposed to high radon levels face a higher risk of ___ than do nonsmokers

lung cancer

what is the SI subunit of measure for EqD?

mSv

which radiation quantity takes into account both the toe of radiation and the part of the body irradiated and is intended to be the best estimate of overall harm that might be produced by a given dose of radiation in human tissue

effective dose

Z number refers to the number of

protons in the nucleus of an atom

bone marrow dose, gonadal dose, and ESE (includes skin and glandular exposure) may be used to indicate

amount of radiation received by a patient

what is term for full range of frequencies and wavelengths of electromagnetic waves

electromagnetic spectrum

the radiation elements in the crust of the earth and in the human body are considered what type of sources of ionizing radiation

natural sources

changes in blood count are a classic example of ___ damage that results from nonnegligible exposure to ionizing radiation

organic or somatic

the EPA considers the second leading cause of lung cancer in the US to be

radon

which of the following is a consumer product that contains radioactive material?

1. airport surveillance systems

2. electron microscopes

3. ionization type smoke detector alarms

1, 2, 3

are alpha particles more harmful as an external source of radiation or as an internal source of radiation

internal

what disease continues to be the main adverse health effect of Chernobyl

thyroid cancer

what is the term for radiation damage to generation yet unborn

genetic damage

use of barium or iodine based contrast medium significantly enhances the occurrence of ___ absorption in biologic tissue and results in an increase in the radiation dose to the patient

photoelectric

define attenuation

any process decreasing the intensity of the primary photon beam

during the process of compton scattering, the energy of the incident x-ray photon is ___ absorbed

partially

what controls the quality or penetrating power of the x-ray beam

kVp (kilovoltage peak)

pair production and ___ do not occur within the range of diagnostic radiology

photodisintegration

which interaction of x-radiation with matter is most responsible for the contrast between bone and soft tissue that is seen on an optimal quality image

photoelectric absorption

scattered radiation can result in

exposure to personnel, radiographic fog on a completed image

a positron is considered as

a form of antimatter

what is most likely to occur at less than 10 keV

coherent scattering

effective atomic number of compact bone

13.8

what is the term for energy absorbed by the patient per unit mass

absorbed dose

___ scattering results in all directional scatter

compton

fluorescent yield means

the number of x-rays emitted per inner shell vacancy