homework review Flashcards
Which of the following is essentially the sum total of air kerma over the exposed area of the patient’s body surface?
absorbed dose
dose area product
effective dose
equivalent dose
dose area product
1500 rems is equal to __________ Sv
15 Sv (1 Sv = 100 rem)
Which of the following rem values equals 4000 mSv?
4
40
400
4000
400 rem
In radiation protection systems no longer in use, a radiation dose to which occupationally exposed persons could be continuously subjected without any apparent harmful actue effects, such as erythema of the skin, was known as a(n)
air kerma
effective dose
tolerance dose
weighted dose
tolerance dose
Ten sieverts equal ______________ millisieverts
10,000
Which of the following is (are) equivalent to 1 rem?
- 1/100 Sv
- 1 centisievert (cSv)
- 10 millisieverts (mSv)
1, 2, and 3
true/false: air kerma denotes a calculation of radiation intensity in air
true
true/false: the concept of tolerance dose was originally developed to protect occupationally exposed persons from any apparent acute effects of radiation exposure, such as erythema
true
true/false: EfD can be expressed in Sv or mSv
true
true/false:
Air kerma is replacing the traditional quantity, absorbed dose
false
Convert 8 rad to Gy
0.08 Gy (1 Gy = 100 rad)
Convert 0.4 Gy to rad
40 rad (1 Gy = 100 rad)
Convert .020 Gy to mGy
20 mGy
Convert 0.3 Sv to mSv
300 mSv
Which of the following are types of ionizing radiation that produce virtually the same biologic effect for equal absorbed doses in body tissue?
x-rays, beta particles, gamma rays
alpha particles, beta particles, gamma rays
x-rays, neutrons, gamma rays
x-rays, alpha particles, fast neutrons
x-rays, beta particles, gamma rays
Which of the following are not SI units?
- Roentgens
- Coulombs per kilogram, grays, Sieverts
- Rads and Rems
1 and 3
_______ rem is equal to 35 mS
3.5
__________ _____________was used as the first measure of exposure for ionizing radiation
skin erythema
Convert 450 rad to Gy
4.5 Gy
Radiation exposure received by radiation workers in the course of exercising their professional responsibilities
occupational exposure
_________________ uses a continuous beam of x-rays to create images of the movement of internal structures that can be viewed on a monitor.
fluoroscopy
__________ imaging is accomplished with fluoroscopy as opposed to radiography
dynamic
The process that the exit radiation from the anatomic area of interest interacts with the input phosphor for conversion to visible light, which are converted to electrons by a photocathode, then focused by electrostatic focusing lenses, and accelerated toward an anode to strike the output phosphor is:
image intensification
The __________________________ consists of a light-emitting material (like cesium iodide) to absorbs x-rays and emits light
input phosphors
This part of the image intensifier absorbs light and converts light to electrons
photocathode
This is measured in cd/m2/mR/s.
conversion factor
The formula for brightness gain is
brightness gain = minification gain × flux gain
When operated in magnification mode, the electrostatic lenses have ________ voltage.
increased
A disadvantage of using magnification mode during fluoroscopy is ___________________-
the patient receives additional dose
Increasing the mA is the way to correct a fluoroscopic image that has:
noise
Vidicon refers to a type of:
camera tube
When the electron beam in the camera travels back and forth across, from the top to bottom, it is moving in a ___________ pattern.
raster
The CCD’s electrical charge from the capacitors is sent to the:
display monitor
The fiber-optic bundle or optical lens system is used to:
link the output phosphor and camera or CCD.
The analog to digital converter
a. makes the electrical signal understandable to the computer and determines the image matrix
b. determines the contrast resolution of the system and determines the image matrix
c. makes the electrical signal understandable to the computer and determines the contrast resolution of the system
d. all options are correct
D. all options are correct
When using the mobile C-Arm unit, the x-ray tube should be positioned under the patient and the image intensifier above the patient because:
reduce radiation exposure to operator.
The newest fluoroscopy systems use a flat-panel detector:
in place of the image intensifier
What feature has replaced automatic brightness control (ABC) on newer fluoroscopic units?
automatic exposure rate control (AERC)
____ reduces the number of images each second, decreases patient dose, and reduces the visibility of patient motion
pulsed fluroscopy
Fluoroscopic equipment should be inspected every
6 months
X-ray and gamma radiation are strongly associated with:
leukemia and cancers of the thyroid, breast, and lung
Which of the following radiation waves has the highest energy?
gamma waves
In the nitrogenous base pairs that make up DNA, adenine bonds with:
thymine
Indirect radiation damage to DNA is mainly caused by low linear energy transfer radiation, such as:
- neutron particles
- x-rays
- gamma rays
2 and 3
DNA mutations can cause:
- cytotoxic effects
- uncontrolled cell growth
- cell death
1, 2, and 3
Recent studies have shown that interventional cardiology personnel have an increased likelihood of developing:
cataracts
The main source of occupational radiation exposure is:
secondary radiation/scatter
The International Commission on Radiological Protection (ICRP) recommends a maximum radiation effective dose of ______ mSv per year, averaged over 5 years, with no more than ______ mSv in 1 year.
20; 50
In the study by Thornton et al, which of the following were found to maximize protection of the eyes’ lenses?
- leaded shields
- leaded table skirts
- protective eyeglasses and drapes used together
1 and 3
Which of the following was NOT mentioned as a function of the thyroid gland?
regulating body temperature
regulating energy levels
regulating metabolism
triggering sexual maturation
triggering sexual maturation
Only ________ of radiation from a 100 kV beam will penetrate a 0.5 mm thick lead apron.
3-7%
What is the main advantage of the ZeroGravity Radiation Protection System?
it places no weight on the operator
According to a study by Hayashi et al, the injection portion of a digital subtraction angiography procedure accounted for more than _________% of the total radiation exposure to the operator
90%
What is the ideal location for a ring dosimeter?
on the ring or pinky finger on either hand
The ICRP recommends that a fetus be exposed to less than _____ mSv during an entire pregnancy.
1.0
Three main conditions a fetus may suffer from as a result of radiation exposure are:
cancer, growth retardation, and congenital malformations
A fetus is most susceptible to the negative effects of radiation during weeks _________ of gestation.
8-15
In general, a fetal dose up to ______ mSv has not been shown to affect pregnancy outcomes.
50
Which of the following are mentioned in the text as ways a pregnant technologist could reduce radiation exposure to her fetus?
- wear 2 protective lead aprons
- postpone learning new techniques until after giving birth
- stand as far away from the beam as possible
1, 2, and 3
true/false: in general, radiologic technologists should avoid being around magnetic resonance imaging equipment during the first trimester of pregnancy, unless it is necessary for a personal diagnosis.
true