homework review Flashcards
What is the average amount of background radiation per year in the United States?
360 rem
Members of the general public who may be exposed to frequent or continuous exposure from artificial sources other than medical exposure have a recommended maximum effective dose equivalent of _____ rem/year.
0.1 rem/year, 1 mSv/year
The maximum dose to the fetus of an occupational worker for the entire gestation period is _____ rem
0.5
What is correct about the 80/20 rule?
80% of the problems come from 20% of causes
Which federal agency is responsible for establishing standards for safety and for monitoring the workplace environment?
OSHA
Which federal agency is responsible for enforcing both equipment standards and radiation safety practices
NRC
Which federal agency is responsible for regulating the design and manufacture of x-ray equipment?
FDA (through the Center for Devices and Radiological Health)
The measurement of the level of quality at some point in time with no effort to change or improve the level of care is known as quality
assessment
Invasive quality control equipment testing is considered to be
complex
Noninvasive quality control equipment testing is considered to be
either simple or complex
How many levels of quality control testing and monitoring are there?
3
Any activity that costs a facility either money or its reputation is known as
loss potential
Customers who come from outside the healthcare organization are generally referred to as
external customers
A cause-and-effect diagram is also known as which of the following?
fishbone chart
A procedure to identify potential failure within a system is
FMEA
How many basic steps are involved in the creation of a TPM?
5
The number of items actually measured from a population is called a
sample
The range of variation around the mean is called
standard deviation
Which of the following is a pictorial representation of a frequency distribution?
histogram
Which of the following is not a tool for data presentation?
brainstorming
Which of the following terms best describes a chart that pictorially demonstrates whether key indicators are moving up or down over a given period of time?
trend chart
Which of the following terms best describes the average set of observations?
mean
Which of the following terms best describes variables that have only two values or choices?
dichotomous variables
Which modality generally display the greatest spatial resolution?
a. DR radiographs
b. Nuclear medicine
c. Digital mammography
d. Magnetic resonance imaging
digital mammography
The window width setting in a digital imaging system is used to manipulate which of the following values?
a. Image contrast
b. Spatial resolution
c. Temporal resolution
d. Pixel brightness
image contrast
What can be thought of as the amount of information recorded in an image divided by the information available in the part?
modulation transfer function
Which of the following terms best describes the ability of an imaging system to create separate images of closely spaced high-contrast objects?
a. Screen speed
b. Spatial resolution
c. Contrast resolution
d. Quantum mottle
spatial resolution
What term is the unit most commonly used to measure luminance?
nit
The type of contrast that is caused by variations in the tissue density within the anatomical part to be imaged defines what?
subject contrast
The amount of light either scattered or emitted by a surface is known as
a. luminance.
b. radiant flux.
c. luminous flux.
d. illuminance.
illuminance (*)
The ability of an imaging system to distinguish structures with similar x-ray transmission as separate entities is known as
contrast resolution
In imaging applications, because contrast resolution and visibility of detail are mandatory for diagnostic interpretation, ____ is important.
a. high DQE
b. low DQE
c. low DI
d. low SNR
high DQE
Detective quantum efficiency (DQE) is a measure of which of the following?
a. Lack of image noise
b. Spatial resolution
c. X-ray absorption
d. Contrast resolution
X-ray absorption
A reduction in brightness at the periphery of the image captured with an image intensifier tube is referred to as
vignetting
At any combination of tube potential and current, fluoroscopic equipment with an automatic brightness control should not produce an entrance skin exposure exceeding ____ R/min.
10
Performance testing of fluoroscopic systems must include all the following except:
a. Automatic brightness control
b. Automatic film processor
c. Total filtration
d. X-ray tube housing
b. Automatic film processor
Quality control tests of fluoroscopic systems should be performed
semiannually
The input phosphor of an image intensifier tube converts a(n) _____ image into a(n) _____ image.
x-ray, light
The maximum entrance exposure rate for fluoroscopic units equipped with AERC is
10 R/min (100 mGya/min)
The photocathode of a fluoroscopic image intensifier is a device that emits
electrons
The television camera most commonly used to capture the fluoroscopic image from a tube type image intensifier is the
charge-coupled device or CMOS
What type of distortion occurs with tube-type fluoroscopic image intensifiers, most often caused by the presence of strong magnetic fields?
S distortion
What type of test tool may be used to demonstrate pincushion distortion?
wire mesh tool
Collimation systems equipped with positive beam limitation must be accurate to within ____ of the SID.
+/- 3%
During the exposure linearity test, the amount of radiation/mAs should vary by no more than ±___% from the average.
10%
If the x-ray field is smaller than that indicated by the indicator knob on the collimator, the radiographer risks
cutting off anatomy of interest
The kilovolts peak (kVp) must be accurate to
+/- 5%
The light field and radiation field of a radiographic unit must be congruent to within ____ of the SID.
+/- 2%
The maximum variation coefficient for reproducibility of x-ray generators is
0.05
The range of sweep angles for digital tomosynthesis units can be from ____ to ____ degrees.
10 to 50
Two common quality control tests that should be performed on grids are grid _____ and grid _____ tests.
alignment, uniformity
Which of the following tests would not be appropriate to check an AEC system?
a. Reproducibility
b. Backup timer verification
c. Ion chamber sensitivity
d. Laser localizer
laser localizer
Which of the following devices can be used as the sensor in AEC units?
a. Ion chamber
b. Solid-state detector
c. Photocell
d. All are correct
All are correct
Which of the following PACS quality control tests are recommended to be performed on at least a quarterly basis?
a. Image resolution evaluation
b. Test pattern image transmit and receive
c. Compression recall
d. All are correct
d. all are correct
Which of the following should be a part of initial acceptance testing of a digital radiographic system?
a. Accuracy of exposure indicator
b. Evaluation of image uniformity
c. Presence of dropped pixels
d. All are correct
d. all are correct
When viewing digital images on a display monitor, the cosine law would apply to what?
off-axis viewing
The most important component affecting the spatial resolution in digital subtraction angiography is the
computer matrix size
The limiting spatial resolution is also known as the
Nyquist frequency
The contrast ratio of a viewing monitor should be higher than
250
Primary display monitors for viewing digital images should have a luminance value higher than ____ nit.
170
Photoconductors convert x-ray energy into
electric current
Five images of a DR detector are acquired all at the same technical factors. The pixel brightness readings within a region of interest compare the relationship of the x-ray output to the pixel values. What quality control test was performed?
reproducibility
Benefits of digital PACS images do not generally include
a. improved spatial resolution.
b. convenient storage.
c. computer-aided diagnosis.
d. image transmission.
improved spatial resolution
