Image Acquisition Flashcards
In digital imaging, brightness is controlled by:
- IR Exposure
- Monitor Functions
- Postprocessing functions
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1,2, and 3
C: 2 and 3 only
In electronic imaging, as digital image matrix size increase:
- Pixel size decreases
- Resolution decreases
- Pixel depth decreases
A: 1 only
B: 2 only
C: 1 and 2 only
D: 2 and 3 only
A: 1 only (pixel size decreases)
An algorithm; as used in xray imaging, is an:
A: Geometric formula
B: Specific exposure factors
C: Series of variable instructions
D: Predetermined exposure factors
C: Series of variable instructions
If you can see lines on the xray , that run same direction as the processor.. It’s called:
A: Part motion
B: Aliasing Artifact
C: Double Exposure
D: Grid cutoff
B: Aliasing Artifact
The intensity of ionizing radiation decreases as:
A: SID decreases
B: SID increases
C: frequency increases
D: wavelength decreases
B: SID increases
Grid interspace material can be made of:
- Carbon fiber
- Aluminum
- Plastic Fiber
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1,2 and 3
C: 2 and 3 only
The reduction in xray photon intensity as the photon passes through material is termed:
A: Absorption
B: Scattering
C: Attenuation
D: Divergence
C: Attenuation
An increase in KVP will have which of the following effects in digital imaging:
- More scattered radiation will be produced
- The exposure rate will increase
- Radiographic contrast will increase
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1, 2, and 3
B: 1 and 2 only
If a lateral xray of the chest is being done on an asthenic patient and outer photocells are selected, what is likely to be the outcome:
A: Decreased IR exposure
B: Increased IR exposure
C: Scattered radiation fog
D: Motion Blur
A: Decreased IR exposure
Which of the following exposure factors will produce the greatest receptor exposure?
A: 100 mA, 50 ms
B: 200 mA, 40 ms
C: 400 mA, 70 ms
D: 600 mA, 30 ms
C: 400 mA, 70 ms
The component of a CR image plate (IP) that records the radiologic image is the:
A: emulsion
B: helium-neon laser
C: photostimulable phosphor
D: scanner-reader
C: Photostimulable phosphor
The radiation dose received by the digital detector for each image is indicated by the:
A: mA meter
B: Exposure indicator
C: KVP selector
D: Histogram
B: Exposure indicator
HVL is affected by the amount of:
- KVP
- Beam filtration
- Tissue density
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1, 2, and 3
B: 1 and 2 only
The luminescent light emitted by the PSP is transformed into the image seen on the CRT by the:
A: PSP
B: Scanner reader
C: ADC (analog to digital converter)
D: Helium-neon laser
C: ADC (analog to digital converter)
Misalignment of the tube-part IR relationship results in..
A: Shape Distortion
B: Size Distortion
C: Magnification
D: Blur
A: Shape distortion
Which of the following inits is used to express resolution?
1) Line-spread function
2) Line pairs per millimeter
3) Line-Focus principle
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1, 2, and 3
B: 1 and 2 only
The term windowing describes practice of:
A: Varying the automatic brightness control
B: Changing the image brightness or contrast scale
C: Varying the FOV
D: Increasing resolution
B: Changing the image brightness or contrast scale
Foreshortening can be caused by:
A: The radiographic object being places at an angle to the IR
B: Excessive distance of OID
C: Insufficient distance of SID
D: Excessive distance of SID
A: The object being placed at an angle
Acceptable methods of minimizing Motion unsharpness is:
1) suspended respiration
2) short exposure time
3) patient instruction
A: 1 only
B: 1 and 2 only
C: 1 and 3 only
D: 1, 2, and 3
D: 1, 2, and 3
Using fixed mAs and variable KVP tech factors, each centimeter increase in pt thickness requires what adjustment in KVP?
A: Increase 2 KVP
B: Decrease 2 KVP
C: Increase 4 KVP
D: Decrease 4 KVP
A: Increase 2 KVP
Unopened boxes of radiographic film should be stored away from radiation and…..?
A: in the horizontal position
B: in the vertical position
C: stacked with the oldest on top
D: stacked with the newest on top
B: in the vertical position
Potential digital image post processing tasks include:
1) PACS
2) Annotation
3) inversion/reversal
A: 1 only
B: 1 and 2 only
C: 2 and 3 only
D: 1, 2, and 3
C: 2 and 3 only
Factors that contribute to film fog include:
1) the age of the film
2) excessive exposure to safelight
3) processor chemistry
A: 1 only
B: 1 and 2 only
C: 1 and 3 only
D: 1, 2, and 3
D: 1, 2, and 3
X-ray photon energy is inversely related to:
1: photon wavelength
2. Applied mA
3. Applied KVP
A) 1 only
B) 1 and 2 only
C) 1 and 3 only
D) 1, 2, and 3
A) 1 only
Characteristics of DR imaging include:
- Solid state detector receptor plates
- A direct capture imaging system
- Immediate image display
A) 1 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3
D) 1, 2, and 3
Compared with a low ratio grid, a high ratio grid will:
- Allow more centering latitude
- Absorb more scattered radiation
- Absorb more primary radiation
A) 1 only
B) 1 and 2 only
C) 2 and 3 only
D) 1, 2, and 3
C) 2 and 3 only
A decrease in KVP will result in:
- A decrease in image resolution
- A decrease in photon energy
- A decrease in receptor exposure
A) 1 only
B) 1 and 2 only
C) 2 and 3 only
D) 1, 2, and 3
C) 2 and 3 only
To be used as an image intensifier screen, phosphor should have which of the following:
- High conversion efficiency
- High X-ray absorption
- High atomic number
A) 1 only
B) 3 only
C) 1 and 2 only
D) 1, 2, and 3
D) 1, 2, and 3
Resolution in CR increases as:
- Laser beam size decreases
- Monitor matrix size decreases
- PSP crystal size decreases
A) 1 only
B) 1 and 2 only
C) 1 and 3 only
D) 1, 2, and 3
C) 1 and 3 only
Which of the following contribute to the performance of a grid:
- Grid ratio
- Number of lead strips per inch
- Amount of scatter transmitted thru the grid
A) 1 only
B) 2 only
C) 1 and 2 only
D) 1, 2, and 3
D) 1, 2, and 3
All of the following affect the exposure rate of the primary beam except:
A) mA
B) KVP
C) distance
D) field size
D) field size
Which of the following terms is used to describe unsharp edges of tiny radiographic details:
A) diffusion
B) mottle
C) blur
D) umbra
C) blur
Pixel is associated with all of the following except:
A) two dimensional
B) picture element
C) measured in xy direction
D) how much of the part is included in the matrix
D) how much of the part in included in the matrix
Using a short (25 - 30 in) SID with a large (14x17) IR is likely to:
A) increase the scale of contrast
B) increase the anode heel effect
C) cause malfunction of the AEC
D) cause premature termination of the exposure
B) increase the anode heel effect
Chemical fog on a radiographic film may be attributed to:
- Excessive developer temperature
- Oxidized developer
- Excessive replenishment
A) 1 only
B) 1 and 2 only
C) 2 and 3 only
D) 1, 2, and 3
D) 1, 2, and 3
Because of the anode heel effect, the intensity of the X-ray bean is greatest along the:
A) path of the central ray
B) anode end of the beam
C) cathode end of the beam
D) transverse axis of the IR
C) cathode end of the beam
The differences between CR and DR include:
- CR uses IPs
- CR has higher DQE, and lower dose
- CR images are displayed immediately
A) 1 only
B) 1 and 2 only
C) 2 and 3 only
D) 1, 2, and 3
A) 1 only
Vogel is associated with all of the following except:
A) bit depth
B) volume element
C) measured in Z direction
D) field of view
D) Field of view
If a radiograph is produced using 12 mAs with a 16:1 ratio grid.. What would the new mAs be if you use a 8:1 ratio grid:
A) 3
B) 6
C) 8
D) 10
C) 8 mAs
The main difference between the direct and Indirect capture in DR is that:
A) direct capture has no scintillator
B) direct capture uses a photostimulable phosphor
C) in direct capture, light is detected by CCDs
D) in direct capture, light is detected by TFTs
A) direct capture has no scintillator
Analog to digital conversion is required in which imaging system:
A) CR
B) DR
C) SF
D) Direct conversion
A) CR
The photostimulable phosphor (PSP) plates used in CR are constructed in layers that include:
- Light shield layer
- Support layer
- Electroconductive layer
A) 1 only
2) 1 and 2 only
3) 2 and 3 only
D) 1, 2, and 3
D) 1, 2, and 3