QA Exam 3

Any image that must be repeated because of human or mechanical error during the production of the initial image is considered to be a repeat image. What effect does a repeat image have on the radiation dose received by the patient?

A) The patient receives no additional radiation dose.
B) The patient's skin and possibly the gonads, if they were in the included imaged area, receive a double radiation dose.
C) The patient's critical organs receive a radiation dose that is 10 times greater than the initial radiation dose.
D) The patient's superficial tissues only receive a radiation dose that is four times as great as that of the original radiation dose.

B) The patient's skin and possibly the gonads, if they were in the included imaged area, receive a double radiation dose.

During a radiographic examination, which of the following combinations of technical exposure factors reduce patient radiation dose?

A) Lower kVp, higher mAs
B) Higher kVp, lower mAs
C) Higher kVp, higher mAs
D) Lower kVp, lower mAs

B) Higher kVp, lower mAs

When a pregnant patient must undergo a radiographic procedure, which of the following practices will minimize radiation exposure?

A) Selecting random technical exposure factors for the part of the body to be imaged and not collimating the primary x-ray beam to ensure full coverage of the image receptor.
B) Opening the x-ray beam collimator shutters as wide as possible to ensure complete coverage of the image receptor.
C) Not collimating the radiographic beam to include only the anatomic area of interest and shielding the lower abdomen and pelvis when this area needs to be included in the area to be imaged.
D) Selecting technical exposure factors that are appropriate for the part of the body to be imaged and precisely collimating the radiographic beam to include only the anatomic area of interest while shielding the lower abdomen and pelvis when this area does not need to be included in the area to be imaged.

D) Selecting technical exposure factors that are appropriate for the part of the body to be imaged and precisely collimating the radiographic beam to include only the anatomic area of interest while shielding the lower abdomen and pelvis when this area does not need to be included in the area to be imaged.

According to the American College of Radiology (ACR), abdominal radiologic examinations that have been requested after full consideration of the clinical status of a patient, including the possibility of pregnancy, need

A) not be postponed or selectively scheduled.
B) to be postponed or selectively scheduled.
C) to be postponed and scheduled at least 10 days after the start of the next menstrual period.
D) to be postponed and scheduled 10 days before the end of the next menstrual period.

A) not be postponed or selectively scheduled.

The reason for discontinuing patient gonadal shielding and fetal shielding in diagnostic radiology is based on research that the use of such shielding may jeopardize the benefits of the radiologic examination because

A) shields are now made of aluminum that will absorb less radiation.
B) the gonads and embryo-fetus are relatively radioresistant.
C) an incorrectly placed shield within the collimated x-ray beam when an automatic collimator is used, can result in the lead in the shield obscuring anatomic information or interfering with the AEC system.
D) shields in the primary x-ray beam do not absorb radiation.

C) an incorrectly placed shield within the collimated x-ray beam when an automatic collimator is used, can result in the lead in the shield obscuring anatomic information or interfering with the AEC system.

Specific area shielding may be selectively used during some x-ray procedures to protect which of the following?

1. Lens of the eye
2. Breast
3. Upper extremities
4. Lower extremities

A) 1 and 2
B) 1 and 3
C) 3 and 4
D) All of the options

A) 1 and 2

According to the U.S. Public Health Service, the genetically significant dose (GSD) for the population of the United States is approximately

A) 1.00 mSv.
B) 0.80 mSv.
C) 0.40 mSv.
D) 0.20 mSv.

D) 0.20 mSv.

Which of the following must always be the first step in protection of the reproductive organs?

A) Adequate and precise collimation of the radiographic beam to include only the anatomy of interest
B) Use of gonadal shielding
C) Use of a mobile protective shielding device
D) Use of digital imaging equipment

A) Adequate and precise collimation of the radiographic beam to include only the anatomy of interest

Motion controlled by will is classified as voluntary motion. Lack of such control may be attributed to which of the following?

1. The patient's age
2. Breathing patterns or problems
3. Physical discomfort
4. Fear of the examination
5. Mental instability

A) 1, 2, 3, 4
B) 2, 3, 4, 5
C) 1, 3, 4, 5
D) 1, 2, 3, 4, 5

D) 1, 2, 3, 4, 5

When a properly calibrated automatic exposure control (AEC) is not employed to obtain a uniform selection of technical x-ray exposure factors, well-managed imaging departments?

A) Estimate technical exposure factors for all radiographic examinations.
B) Have the radiologist determine and set up all technical exposure factor charts.
C) Use technique charts borrowed from another imaging facility.
D) Make use of standardized technique charts that have been established for each x-ray unit in that facility.

D) Make use of standardized technique charts that have been established for each x-ray unit in that facility.

Reducing the field size to the anatomic features of interest not only reduces patient exposure but also

A) increases completed image quality by decreasing scatter.
B) decreases completed image quality by increasing scatter.
C) increases completed image quality by increasing scatter.
D) decreases completed image quality by decreasing scatter.

A) increases completed image quality by decreasing scatter.

Because multiple bony areas span the entire body, the radiation dose absorbed by the organ called bone marrow

A) can be accurately measured by a direct method.
B) cannot be measured by a direct method; it can only be estimated.
C) is not of concern during any diagnostic radiography examinations.
D) can only be measured to a small degree by a direct method.

B) cannot be measured by a direct method; it can only be estimated.

A blotchy radiographic image that results when an insufficient quantity of x-ray photons reaches the image receptor is called

A) quantum noise, or mottle.
B) random photon displacement.
C) spatial resolution.
D) photon abrasions.

A) quantum noise, or mottle.

Which of the following is frequently a problem in diagnostic pediatric radiography?

A) Lack of availability of appropriate pediatric immobilization devices
B) Lack of patience on the of the radiographer when imaging children
C) Finding imaging equipment that can accommodate pediatric imaging
D) Patient motion

D) Patient motion

Essentially all diagnostic medical procedures result in fetal exposures ______________, so that _______________________.

A) greater than 5 Gy; the risk of abnormality is large
B) greater than 1 Gy; the risk of abnormality is large
C) of less than 0.5 Gy but greater than 0.01 Gy; the risk of abnormality is small
D) of less than 0.01 Gy; the risk of abnormality is very small

D) of less than 0.01 Gy; the risk of abnormality is very small

Of the following radiologic procedures, which is (are) considered nonessential?

1. A chest x-ray examination automatically scheduled on admission to the hospital
2. Lumbar spine x-ray examination as part of a pre-employment physical
3. Whole-body computed tomography (CT) screening

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) All of the options

D) All of the options

Which of the following uses photostimulable phosphors?

A) Indirect conversion DR system
B) Direct conversion DR system
C) CR systems
D) Flat panel fluoroscopic systems

C) CR systems

Which material is most often used in the input phosphor of an image intensifier?

A) Calcium tungstate
B) Cesium iodide
C) Zinc cadmium sulfide
D) Lanthanum oxybromide

B) Cesium iodide

Which of the following is an advantage of DR systems vs. analog radiography?

A) Lower patient dose
B) Higher contrast resolution
C) Edge enhancement
D) All of the above

D) All of the above

Which of the following identifies the fluoroscopic scan mode by which the x-ray tube delivers radiation in short, high-intensity pulses?

A) Continuous fluoroscopic mode
B) Pulsed, interlaced scan mode
C) Slow scan mode
D) All of the above

B) Pulsed, interlaced scan mode

In direct capture DR systems, remnant radiation is converted into an electric signal by:

A) PSP crystals
B) Amorphous selenium
C) Cesium iodide
D) Amorphous silicon

B) Amorphous selenium

A reduction in brightness at the periphery of the image captured with an image intensifier tube is referred to as:

A) Pincushion distortion
B) Vignetting
C) Barrel distortion
D) Quantum mottle

B) Vignetting

What does PACS stand for?

A) Picture Arrival and Communication System
B) Picture Archiving and Communication System
C) Patient Archiving & Communication Service
D) Photostimulable Archive Control Software

B) Picture Archiving and Communication System

What is the "active" layer of a CR imaging plate?

A) PSP
B) TFT
C) Analog to digital converter
D) Laser

A) PSP (photostimulable phosphor)

In departments with a quality management program in place, the greatest number of repeat images is caused by which of the following?

A) equipment problems
B) Image fog
C) Patient motion
D) Positioning error

D) Positioning error

The variability allowed for mAs linearity is +/- ___________%.

A) 2
B) 5
C) 10
D) 20

C) 10

Data for determining repeat rates should include at least ____ patients to obtain a statistical sample large enough for valid results.

A) 100
B) 150
C) 250
D) 500

C) 250

The ability of an imaging system to distinguish structures with similar x-ray transmission as separate entities is known as:

A) contrast resolution
B) spatial resolution
C) temporal resolution
D) spectral matching

A) contrast resolution

Detective Quantum Efficiency (DQE) is a measure of which of the following?

A) Contrast resolution
B) Image noise
C) Spatial resolution
D) X-ray absorption and conversion to signal

D) X-ray absorption and conversion to signal

What is a test of the efficiency for contrast resolution, showing how well a machine can detect differences in body parts that absorb X-rays very similarly?

A) Modulation Transfer Function (MTF)
B) Detective Quantum Efficiency (DQE)
C) Spatial resolution test
D) Signal-to-noise ratio (SNR)

B) Detective Quantum Efficiency (DQE)

Higher detective quantum efficiency (DQE) will result in:

A) Lower image quality and lower patient dose
B) Higher image quality and higher patient dose
C) Lower image quality and higher patient dose
D) Higher image quality and lower patient dose

D) Higher image quality and lower patient dose

DQE is most specifically a measure of:

A) Contrast resolution
B) Digital data file size
C) Image noise
D) Spatial resolution
E) X-ray absorption

E) X-ray absorption

A DR flat panel detector element (DEL) size will help to determine which of the following?

A) contrast resolution
B) detective quantum efficiency (DDQE)
C) spatial resolution
D) dynamic range

C) spatial resolution

The maximum dose to the fetus of an occupational worker for the entire gestation period is measured in rem.

A) 0.1 rem
B) 0.5 rem
C) 1.5 rem
D) 3.0 rem

B) 0.5 rem

Which of the following best describes the type of artifact that results from projecting a curved surface onto a flat surface, where magnification increases toward the periphery of the image?

A) Veiling glare
B) Pincushion distortion
C) Distortion
D) Vignetting

B) Pincushion distortion

Which of the following is the main advantage of using a multifield image intensifier?

A) The field of view is increased
B) The image brightness is increased
C) Magnification option is available
D) The patient dose is increased

C) Magnification option is available

A photocathode is a device that emits

A) Light photons
B) X-ray photons
C) Electrons
D) All of the answer options are correct

C) Electrons

The input phosphor of an image intensifier tube converts a(n) _____ image into a(n) _____ image.

A) X-ray; light
B) Light; electron
C) Electron; light
D) X-ray; electron

A) X-ray; light

Which of the following is not a "tube" type of television camera?

A) Orthicon
B) Plumbicon
C) Vidicon
D) CCD

D) CCD

The television camera most commonly used to capture the fluoroscopic image from a tube-type image intensifier is the:

A) Vidicon
B) Plumbicon
C) Charged-coupled device
D) Image orthicon

C) Charged-coupled device

Fluoroscopy equipment visual inspections are done:

A) Monthly
B) Semi-annually
C) When state inspectors are present
D) Annually

B) Semi-annually

The intensity of the X-ray beam at the tabletop should not exceed ______ R/min for units that are equipped with an automatic brightness stabilization system?

A) 3
B) 5
C) 10
D) 20

C) 10

The most important component affecting the spatial resolution is:

A) Focal spot size
B) Image intensifier
C) Television camera
D) Computer matrix size

D) Computer matrix size

Which federal agency is responsible for establishing standards for safety and monitoring the workplace environment?

A) NRC
B) OSHA
C) FDA
D) NERI

B) OSHA

Which of the following should be part of the initial acceptance testing of a digital radiographic system?

A) Evaluation of image uniformity
B) Presence of dropped pixels
C) Accuracy of exposure indicator
D) All of the above

D) All of the above

Which of the following terms best describes the increase in image brightness resulting from the difference in size between the input and output phosphors?

A) Brightness gain
B) Flux gain
C) Minification gain
D) Resolution gain

C) Minification gain

The __________________ absorbs x-rays and emits light.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Accelerating anode

A) Input phosphor

This part of the image intensifier absorbs light and produces electrons.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Electrostatic focusing lenses

C) Photocathode

What do electrostatic lenses do in the image intensifier tube?

A) Focus the stream of electrons toward the anode
B) Convert x-ray photons into light photons
C) Accelerate electrons toward the output phosphor
D) Convert electrons into light photons

A) Focus the stream of electrons toward the anode

What does the anode do in the image intensifier tube?

A) Accelerates electrons toward the output phosphor
B) Focuses the electron stream
C) Converts light photons into electrons
D) Converts electrons into light photons

A) Accelerates electrons toward the output phosphor

The __________________ absorbs electrons and emits light.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Accelerating anode

B) Output phosphor

This part of the image intensifier is made of cesium iodide.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Accelerating anode

A) Input phosphor

This part of the image intensifier is made of cesium and antimony compounds.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Electrostatic focusing lenses

C) Photocathode

This part of the image intensifier is made of silver-activated zinc cadmium sulfide.

A) Input phosphor
B) Output phosphor
C) Photocathode
D) Accelerating anode

B) Output phosphor

The purpose of a beam-splitting mirror is to:

A) View the fluoroscopic image on more than one television
B) Reduce the intensity of the image from the output phosphor
C) Allow spot filming to be done during fluoroscopy
D) All of the above

C) Allow spot filming to be done during fluoroscopy

The type of contrast that is caused by variations in the tissue density within the anatomical part to be imaged defines which of the following?

A) Image contrast
B) Subject contrast
C) Inherent contrast
D) None of the answer options are correct

B) Subject contrast

Which term describes the same exposure to the image receptor (IR) when the same milliampere-seconds (mAs) is used, even if different milliampere (mA) and time settings are applied?

A) Exposure linearity
B) Exposure uniformity
C) Exposure reproducibility
D) Exposure timer accuracy

C) Exposure reproducibility

A "multiple field" image intensifier (II) means the user has the ability to change magnification modes.

A) True
B) False

A) True

The minimum source-to-skin distance for fluoroscopy stationary units is:

A) 12"
B) 10"
C) 18"
D) 15"

D) 15"

The SMPTE test pattern is primarily used for:

A) Evaluating the spatial resolution of an X-ray tube
B) Standardizing and assessing the performance of a display monitor
C) Measuring patient dose during fluoroscopy
D) Calibrating the output phosphor of an image intensifier

B) Standardizing and assessing the performance of a display monitor

What is the primary function of a photodiode?

A) Converts X-rays into light
B) Converts light directly into electrons
C) Converts electrons into light
D) Converts photons into heat

B) Converts light directly into electrons

Photoconductors convert X-ray energy into:

A) Light energy
B) Heat energy
C) Radiofrequencies
D) Electric current

D) Electric current

Limiting factor to spatial resolution in digital imaging is the Nyquist frequency and is = to 1/2 the sampling frequency

A) True
B) False

A) True

what happened if nyquist frequemcy is not reached?

spatial resolution goes down (pixel pitch will increase)

Measurement of spatial resolution; half the sampling frequency/ pixels per mm:

A) MTF
B) Nyquist frequency
C) ELT
D) DQE

B) Nyquist frequency

DQE is a masurement of what?

test of efficiency 

MTF - modulation transfer function

how well system can see objects close together

what is a fill factor?

sensing area where it receives photons

What does EI stand for in digital radiography?

A) Exposure indicator

B) Entrance image

C) Energy inversion

D) Efficiency index

A) Exposure indicator

What is dark noise caused by?

A) Electronic noise within the system

B) Excessive ambient light reaching the detector

C) Overexposure of the digital detector

D) Scattered radiation from surrounding structures

A) Electronic noise within the system (System issue)

what type of equipment uses mA setting in the 100s?

digital fluoro (professor JJ might get rid of the question)

What is the term for an image storage type that is completely reversible?

A) Lossless

B) Lossy

C) Reversible compression artifact

D) Uncompressed data

A) Lossless

__________ is the process of assigning a value to a dead pixel based on the recorded values of adjacent pixels.

A) Interpretation
B) Interpolation
C) Interstate
D) Flat-fielding

B) Interpolation