Final - All chapters Flashcards
In the presence of oxygen, the _________ effect is amplified with _______ LET radiation.
indirect, low
Which of the following is true regarding the multi-target model of cell lethality?
a. The critical target is considered to be the cells RNA.
b. Cells have more than one critical target, each of which has to be inactivated for cell death to occur.
c. The cell can accumulate radiation dose.
d. Only cell death can be measured with accuracy.
Cells have more than one critical target, each of which has to be inactivated for cell death to occur.
Which of the following statement(s) is/are true about target theory?
The key sensitive target molecule is DNA.
Hits occur only by indirect effect.
Radiation interaction with the targets is random.
1 & 3
Which of the following phases of the cell cycle is considered most radioresistant?
a. M phase
b. late S phase
c. G1 phase
d. I phase
late S phase
Irradiating human cells with a high LET radiation follows which model?
Single target, single hit
T/F: The lethal effects of cell irradiation are measured by cell death.
False
Measured by cell survival
Oxygen would enhance the effects of which type of radiation the most?
xray
When irradiated with x rays, human cells follow which model?
Multi-target, single-hit model
T/F: The effect oxygen has on high LET radiation is considered irrelevant.
True
This term is related to a cell’s capacity to recover from a sublethal dose.
DQ
This term is referred to as the threshold dose.
DQ
This term is represented by the width of the shoulder on a multi-target, single-hit curve.
DQ
This term is the dose necessary to reduce the survival rate of a cell population to the equivalent of D37.
D0
This term is a statistical measure that refers to a radiation dose level sufficient enough to kill 63% of cells in a population.
D37
This term is constant to cell radiosensitivity.
D0
This term is also known as the mean lethal dose.
D0
T/F: Grenz rays were a type of x-ray that were used to treat cancer.
False
What is the SED50 for humans?
5 Gy
T/F: The latent period occurs right after an acute exposure to radiation.
False
This type of multi-hit chromosome aberration occurs when adjacent chromosomes suffer one hit each and recombine with each other:
Dicentric
T/F: The LD50/30 is the amount of radiation to kill 30% of the population in 50 days.
False
T/F: Isochromatids are the least common type of single-hit aberration.
True
Which of the following is not a type of acute radiation sickness:
a. Hematologic syndrome
b. CNS syndrome
c. Hematopoietic syndrome
d. GI syndrome
c. Hematopoietic syndrome
Another name for deterministic effects is:
nonstochastic
This mean survival time for which type(s) of acute radiation syndrome is dose dependent:
Hematologic syndrome
Gastrointestinal syndrome
Central Nervous System syndrome
1 & 3
Ovaries and testes respond differently to radiation exposure because of:
gametogenesis
T/F: A dose of 5 Gy to the testes would result in temporary sterility.
False
________ desquamation is considered the clinical tolerance for radiation therapy.
Moist
T/F: Acute radiation lethality follows a non-linear, threshold curve.
True
What is the correct order in which the following will occur after an acute exposure to radiation:
Manifest Illness
Prodromal period
Latent period
2
3
1
T/F: Multi-hit chromosome aberrations are observed at rapidly increasing levels in exposures greater than 1 Gy.
True
Erythrocytes are _________ sensitive to radiation because of their longer life span.
less
What is the LD50/60 for humans:
3.5 Gy
In which of the following multi-hit chromosome aberration is DNA actually re-arranged:
a. Ring
b. Dicentric
c. Reciprocal Translocation
d. Separation of Bases
c. Reciprocal Translocation
T/F: Lymphocytes are the human cell type that is most commonly used for cytogenic analysis.
True
Requires a dose of .01 Gy
Delay of Menstruation
Requires a dose of 10 to 50 Gy
G.I. Syndrome
Requires a dose of 2 to 10 Gy
Hematologic Syndrome
Has a mean survival time that remains constant
G.I. Syndrome
Requires a dose of 5 Gy
Permanent Sterility
Requires a dose of > 50 Gy
CNS Syndrome
T/F: The diagnostic beam always results in whole body exposure.
False
The two most radiosensitive cells are:
lymphocytes and spermatogonia
Multi-hit chromosome aberrations follow which dose response curve:
non-linear, non- threshold
Which of the following is the most radiosensitive period for a fetus?
1st trimester
What is the latent period for radiation-induced leukemia?
4 - 7 years
The latent period range for radiation induced cataracts is?
5 - 30 years, with an average of 15 years
The BEIR committee concluded that less than _____ may not be harmful.
0.1 Gy/yr
Radium watch dial painters in the 1920s and 1930s demonstrated which type of cancer?
Bone
Cataracts follow which type of dose response relationship?
nonlinear, threshold
The amount of radiation exposure that causes twice the frequency of a genetic mutation in a population is called?
Doubling Dose
In which of the following populations has Leukemia been observed:
1.Radiologists
2.Ankylosing Spondylitis Patients
3.TB Patients
1 & 2
Which of the following terms describes radiation damage which increases the probability of causing a late effect, but will not increase the severity of the effect?
a. Non-stochastic
b. Congenital
c. Chronic
d. Stochastic
d. Stochastic
A fetus receives .02 Gy of radiation exposure during the first two weeks of gestation and a spontaneous abortion did not result. What would the most likely response would be?
Nothing
What is the minimum radiation dose below which no genetic or cancer effects would occur?
No such levels
Radiation induced skin cancer follows a ___________ dose response relationship.
threshold
What is the best estimate for radiation-induced life-span shortening?
10 days/0.01 Gy
Miners developed lung cancer after being exposed to which type of radiation?
Radon
T/F: Radiation induced mutations are recessive.
True
T/F: Liver cancer was observed in patients that received Conray, a contrast agent used in angiography studies.
False
T/F: There is strong evidence that links radiation exposure to genetic effects in humans.
False
Radiation-induced leukemia follows a _________, ________ dose response curve.
linear, non-threshold
Which of the following statements regarding stochastic effects is false?
a. They are also known as late term effects.
b. They follow a linear, threshold dose response curve.
c. They are chronic in nature.
d. All the statements are false.
b. They follow a linear, threshold dose response curve.
The difference between observed cases and expected cases best defines:
Excess risk
If a technologist is exposed to 4 mGy/hr for 45 minutes during a fluoroscopy exam, what will her total exposure be?
3 mGy
The NCRP is the:
National Council of Radiation Protection
When using the inverse square law during fluoroscopy, the patient should be considered a/an _____________ source of radiation.
point
Exposure is measured by multiplying ______________ by ________________.
exposure rate, exposure time
The best approach to manage occupational radiation exposure is to:
Follow the concept of ALARA
T/F: Effective dose is the equivalent to whole-body dose.
True
The first radiation health physicists worked with:
the atom bomb
T/F: Dose to an individual is directly related to technique used, not to duration of exposure.
False
Health physics is concerned with minimizing radiation dose to:
a. radiation physicists
b. all of the above
c. the public
d. radiation workers
b. all of the above
T/F: TVL is defined as the thickness of absorber that reduces radiation intensity to 1/8th its original value.
False
If a technologist is receiving2 mGy/hr standing 1 foot from the patient during fluoroscopy what is his rate of exposure when he steps back to a; distance of 2 feet from the patient?
.50 mGy/hr
The three cardinal principals of radiation protection involve:
time, distance and shielding
T/F: he concept of effective dose accounts for the relative radiosensitivity of various tissues and organs.
True
T/F: Equivalent whole-body dose is the weighted average of the radiation dose to various organs and tissues.
True
The assumed constant Kilovolt Peak for diagnostic imaging is?
100kVp
How tall must primary protective barriers be?
7’
The maximum variation in linearity is +/-:
10%
Reproducibility of output intensity should be accurate to within +/-:
5%
T/F: The quality control area of an imaging department would be considered an uncontrolled area:
False