Radio Exam 3 Flashcards
The latent period in radiation biology is the time between…
Exposure to x-radiation and clinical symptoms
A free radical
An uncharged molecule, has an unpaired electron in the outer shell, highly reactive/unstable, combines with molecules to form toxins
Direct radiation injury occurs when…
X-ray protons hit critical targets within a cell
Indirect radiation injury occurs when…
X-ray photons are absorbed and form toxins
Which relationship describes the response of tissues to radiation
Linear, nonthreshold
Which factors contribute to radiation injury
Total dose, dose rate, age, cell sensitivity
Long-term effects are seen with small amounts of radiation absorbed in a long period
True
Radiation injuries that are not seen in the person irradiated but that occur in future generations are termed…
Genetic effects
What is most susceptible to ionizing radiation
Small lymphocyte
The sensitivity of tissues to radiation is determined by
Mitotic activity, cell differentiation, cell metabolism
What is considered radioresistant
Mature bone cells
An organ that, if damaged, diminishes the quality of an individuals life is termed
Critical
The traditional unit for measuring x-ray exposure in air is termed
Roentgen
Which radiation unit is determined by the quality factor (QF)
Rem
The unit for measuring the absorption of x-rays is termed
Rad
1 R = 2.58 X 10 to the -4 C/kg, 1 Gy = 100 rad, 1 Sv = 100 rem, 1 rem = rad X QF
All correct conversions
What traditional unit does not have an SI equivalent
Roentgen
What is used only for x-rays
Roentgen
What is the approximate average dose of background radiation received by an individual in the United States
300 mrem/ 3.0 mSv
What is the greatest contributor to artificial radiation exposure
Medical radiation
The amount of radiation exposure an individual receives varies depending on
Receptor type, collimation, technique
A single intraoral image using digital sensor results in an effective exposure dose of
0.002 mSv
What is the dose at which leukemia induction is most likely to occur
5000 mrad (0.05) Gy
Smallest effective does using digital receptors
Single periapical/rectangular collimation
Second smallest effective dose using digital receptors
Single bite-wing/round collimation
3rd/medium effective dose using digital receptors
Panoramic
4th/large effective dose using digital receptors
Complete series/rectangular collimation
Largest effective dose using digital receptors
Complete series/round collimation
Smallest annual source of radiation exposure
Consumer products
2nd annual source of radiation exposure
Terrestrial (soil)
3rd annual source of radiation exposure
Cosmic (space)
4th annual source of radiation exposure
Medical procedures
Largest annual source of radiation
Radon and thoron
Localization of foreign objects is the most important use of dental images
False
When images are properly prescribed, the benefit of disease detection does not outweigh the risk of small doses of radiation
False
Through the use of dental images, the dental professional can detect diseases, lesions, and conditions of the jaws that cannot be identified clinically
True
A dental image contains less information than a written record
False
Missing, extra, and impacted teeth can be identified on a dental image
True
The dental radiographer is any person who positions, exposes, and processes dental x-ray receptors
True
The dental radiographer is assigned only to position and expose dental x-ray imaging receptors
False
The dental radiographer may be assigned to monitor and implement quality control procedures
True
Patient and operator protection must be primary concerns of the dental radiographer
True
Operator competence is maintained by repeatedly performing dental imaging duties
False
Skills that promote a good relationship between individuals are termed facilitation skills
False
Interpersonal skills are skills that are used to make communication easier and develop a trusting relationship between the patient and the dental professional
False
A patient must always be greeted by their first name
False
The dental auxiliary must develop a fast paced, confident chairside manner
False
What does the term bite-wing refer to
Patient bites on a wing/bite block/ tab to stabilize the film
What size film is recommended for use with bite-wing tech in adult patient
2
What size receptor recommended for bite-wing tech in pediatric patient with primary dentition
0
What is primary use of bite-wing images
Interproximal decay/caries detection
What size receptor used to include all the posterior teeth in one bite-wing exposure
3
What type of angulation is determined by the up-and-down movement of the position-indicating device
Vertical angulation
What type of angulation is determined by the side-to-side movement of the PID
Horizontal angulation
When the central ray of the x-ray is not directed through the contact areas of teeth, what error is seen on the resulting image
Overlapped contacts
Correct vertical angulation with bite-wing tech/bite tab
+10 degrees
What describes the relationship of the receptor to maxillary and mandibular teeth in bite-wing tech
Receptor and teeth are parallel to each other
Anterior bite-wings can be placed horizontally
False
Anterior bite-wings can be placed vertically
True
Posterior bite-wings can be placed horizontally
True
Posterior bite-wings can be placed vertically
True
Anterior periapical receptors are always exposed first
True
Posterior periapical receptors are exposed after anterior periapicals
True
Bite-wing receptors are exposed last
True
What is exposed first
Periapicals, maxillary anterior
What is exposed second
Periapicals, mandibular anterior
What is exposed 3rd
Periapicals, posterior
What is exposed 4th
Bite-wing premolars
What should be exposed last
Bite-wing molar
With total dose more damage occurs when tissues absorb _____ quantities of radiation
Large
With dose rate more damage takes place with _______ dose rates because repair cannot take place
High
With amount irradiated more damage occurs when _____ amounts of the body are exposed to radiation
Large
With cell sensitivity more damage occurs in cells that are more ______ to radiation
Sensitive
With age persons who are _____ are more susceptible to damage than persons who are _____
Children, adults
With stochastic effects the severity of the response is _______ of the dose
Not depended on magnitude
With non-stochastic effects the severity of the effect increases with _____ dose
Exposure
Examples of stochastic effects
Induction of leukemia/other cancers
Examples of non-stochastic effects
Loss of hair, skin erythema, cataracts, decreased fertility, radiation sickness, fetal death, teratogenesis
Sequence of radiation injury
Latent period, injury within cells, recovery
Short term effects are associated with ____ amounts of radiation absorbed in a ____ time
Large, short
Short term effects
Nausea, vomiting, diarrhea, hair loss, hemorrhage
Long term effects
Cancer, birth/genetic defects
Bone marrow
Radiosensitive
Intestinal mucosa
Radiosensitive
Salivary gland
Radioresistant
Lens of eye
Radiosensitive
Kidney
Radioresistant
Oral mucosa
Radiosensitive
Liver
Radioresistant
Reproductive cells
Radiosensitive
Nerve tissue
Radioresistant
Skin
Radiosensitive
Thyroid gland
Radiosensitive
Muscle tissue
Radioresistant
Exposure unit of measurement traditional system
Roentgen (R)
Dose unit of measurement traditional system
Radiation absorbed (Rad)
Measurement for dose equivalent traditional system
Roentgen equivalent (in) man (rem)
MPD per year
5.0 rem
SI system measurement unit for dose
Gray (Gy)
SI measurement unit for dose equivalent
Sievert (SV)
4 ways to limit patient exposure
Rectangular collimation, digital sensor, increase target receptor distance, fast film
Bite wing exams are used to examine level of ____ bone
Crestal
How much does exposure decrease with use of film
50%-90%
How much is absorption reduced using F-speed instead of D-speed
60%
Stochastic effects
Genetic effect
Threshold curve
Below certain level no response seem. Response on left dose on bottom
