RAD Image Q&A Final Exam

Approximately what percentage of the removed electrons are "trapped" in the conduction band? A. 1% B. 25% C. 50% D. 99%

C. 50%

A radiographer receives greater exposure during fluoro procedures at a _____ degree angle. A. 30 B. 45 C. 90 D. 120

C. 90

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

A loss of brightness around the edge of the fluoroscopic image caused by the curve of the photocathode is.. A. Noise B. Pincushion appearance C. Vignetting D. Magnification

C. Vignetting

The output phosphor of the image intensifier is composed of ___________________. A. Cesium iodide B. Antimony C. Zinc cadmium sulfide D. Graphite

C. Zinc cadmium sulfide

Visibility of anatomic structures is accomplished by balancing... 1. Contrast 2. Distortion 3. Brightness

Contrast and Brightness only

When using a grid, what 2 things increase?

Contrast and patient dose.

When kVp is increased, what happens to contrast?

Contrast decreases.

What happens to contrast when collimation is increased?

Contrast increases.

When OID increases, what happens to contrast?

Contrast increases.

A material that absorbs x-ray energy and emits visible light in response is a... A. CCD B. Photoconductor C. Thin film transistor (TFT) D. Scintillator

D. Scintillator

Increasing the matrix size for a fixed field of view (FOV) results in: A. Smaller pixel sizes B. Larger pixel sizes C. Increased spatial resolution D. Smaller pixel sizes and increased spatial resolution

D. Smaller pixel sizes and increased spatial resolution

An electron gun can be found in the... A. TV monitor B. CCD C. Vidicon camera D. TV monitor and Vidicon camera

D. TV monitor and Vidicon camera

(T/F) All of the radiation that reaches the image receptor is used to create the radiographic image.

False

(T/F) Because it reduces spatial resolution, it is always best to minimize shape distortion in radiographic imaging.

False

(T/F) Each electron that interacts with the output phosphor results in significantly fewer light photons being produced in comparison with the number of light photons it took to release that electron.

False

(T/F) Scatter radiation is not a significant concern with digital imaging because the computer can adjust the image brightness and contrast.

False

(T/F) When using magnification mode, the operator needs to set the exposure factors higher to compensate for the reduced diameter useful input phosphor

False

What happens to patient dose when collimation increases?

Patient dose decreases.

When SID increases, what happens to patient dose?

Patient dose decreases.

When OID increases, what happens to patient dose?

Patient dose increases.

When mAs is increased, what happens to patient dose?

Patient dose increases.

The formula to determine the amount of magnification created when in magnification mode is...

MF= full size input phosphor/ selected input phosphor

Place the following in order from most to least effect on spatial resolution. OID FSS Motion SID

Motion OID FSS SID

Does increasing the Focal Spot Size increase or decrease receptor exposure, contrast, or patient dose?

None of the above. It doesn't affect any of those 3.

Does mAs have anything to do with contrast or spatial resolution?

Nope. Try again shawty.

What are the only 2 technical factors that decrease spatial resolution?

OID and Focal Spot Size.

When OID increases, what happens to receptor exposure?

OID has nothing to do with receptor exposure.

When mAs is increased, what happens to Receptor Exposure?

R.E increases

What happens to receptor exposure when collimation is increased?

Receptor exposure decreases.

When SID increases, what happens to receptor exposure?

Receptor exposure decreases.

When using a grid, what happens with receptor exposure?

Receptor exposure decreases.

When filtration is increased, what 3 things decrease?

Receptor exposure, contrast, and patient dose.

When SID increases, what happens with contrast?

SID has nothing to do with contrast.

What is the only technical factor that will increase spatial resolution?

SID.

When kVp is increased, what happens to receptor exposure and patient dose?

They both increase.

(T/F) A digital imaging system that displays a greater number of shades of gray has better contrast resolution.

True

(T/F) Automatic Exposure Rate Control (AERC) is used in digital fluoroscopy and is similar to Automatic Brightness Control (ABC)

True

(T/F) CR and DR spatial resolution is lower than the conventional radiography (film)

True

(T/F) It is impossible to produce a radiographic image without unsharpness.

True

(T/F) Pulse rate refers to how many pulses occur per second of operation

True

(T/F) The ABC can be slow in responding, seen as a brief delay in brightness adjustment.

True

(T/F) The magnification factor formula is SID/SOD

True

(T/F) The radiographer should evaluate the exposure indicator value along with the quality of the digital image before determining whether a repeat image is warranted.

True

(T/F) The shape of the histogram corresponds with both anatomy and technique.

True

(T/F) Window level controls brightness.

True

What is the formula for % magnification?

(IW-OW)/OW x 100

Lead gloves should contain how much Pb/eq?

.25 mm Pb/eq

Detector elements used during indirect conversion.. 1. Contain photodetectors 2. Absorb light from the scintillator 3. Generate electrical charges

1, 2, and 3

In order to minimize shape distortion in the image, what 3 factors should be properly aligned? 1. X-ray tube 2. IR 3. OID 4. Anatomic part

1, 2, and 4

Europium serves as A. An activator for the phosphor B. The protective layer C. The reflective part of the PSP plate D. The conductive layer

A. An activator for the phosphor

An 8 bit word is a.. A. Byte B. Pixel C. Matrix D. DICOM

A. Byte

Part of the DR system with indirect capture, the light-sensitive device that is commonly found in digital cameras is the.. A. CCD B. Photoconductor C. Thin film transistor (TFT) D. Scintillator

A. CCD

The scintillator for the indirect capture DR system that utilizes a CCD is... A. Cesium iodide B. Barium fluorohalide C. Amorphous selenium D. Crystalline silicon

A. Cesium iodide

Which of the following is correct regarding the display feature windowing? A. Changing the window level will change the brightness level B. Increasing the window width will increase contrast C. Decreasing the window width will decrease contrast D. Changing the window level has no effect on the brightness level

A. Changing the window level will change the brightness level

Which of the following imaging systems uses a cassette, a photostimulable phosphor plate, a plate reader, and a computer workstation? A. Computed radiography B. Computed tomography C. Direct radiography D. Computed radiography and computed tomography

A. Computed radiography

Carestream (Kodak) uses ______ numbers and higher numbers indicate: A. EI, higher exposures to the IR B. EI, lower exposures to the IR C. S, increased exposure to the IR D. S, decreased exposure to the IR

A. EI, higher exposures to the IR

Tube angulation will produce which of the following types of distortion? A. Elongation B. Foreshortening C. Magnification D. Minification

A. Elongation

A radiographic image that is too light has _____ to visualize the anatomic structures. A. Excessive brightness B. Excessive contrast C. Insufficient brightness D. Sufficient contrast

A. Excessive brightness

If the X-ray tube is angled perpendicular to the image receptor but the body part is angled, what will be the result? A. Foreshortening B. Elongation C. Minification D. Loss of density

A. Foreshortening

A radiographic image that has brightness levels that are very different from each other.. A. Has high contrast B. Has low contrast C. Has long-scale contrast D. Has low contrast and has long-scale contrast

A. Has high contrast

A small pixel size will produce radiographs with: A. High spatial resolution B. Low spatial resolution C. Narrow latitude D. High contrast

A. High spatial resolution

Increasing SID= _________ recorded detail (Spatial resolution) A. Increased B. Decreased

A. Increased

A lower pixel value will be seen as: A. Increased brightness level B. Decreased brightness level C. Increased density D. Increased spatial resolution

A. Increased brightness level

Which of the following digital image receptors does NOT use a network of TFT's? A. Indirect capture with CCD B. Indirect capture with amorphous silicon photodetector C. Direct capture with amorphous selenium photoconductor D. None of these use TFT's

A. Indirect capture with CCD

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 is made of cesium iodide. A. Input phosphor B. Output phosphor C. Photocathode D. Accelerating Anode

A. Input phosphor

What fluoroscopic feature allows the position of the collimator plates to be viewed on the monitor without exposing the patient to radiation? A. Last image hold B. Frame averaging C. Digital subtraction D. Electronic magnification

A. Last image hold

The trapped electrons in the conduction band of the PSP form the.. A. Latent image B. Manifest image C. Visible image D. Latent image and visible image

A. Latent image

Data stored in the computer and used to substitute new values for each pixel during processing is.. A. Look-up table (LUT) B. PACS C. Histogram D. Rescaling

A. Look-up table (LUT)

A narrow histogram will also represent: A. Lower contrast B. Higher contrast C. Less spatial resolution D. Greater spatial resolution

A. Lower contrast

The electrostatic focusing lenses have a _________ charge. A. Negative B. Positive C. Neutral D. Changing

A. Negative

The highest spatial frequency that a digital detector can record is the.. A. Nyquist frequency B. Modulation transfer function (MTF) C. Limiting spatial resolution (LSR) D. Detective quantum efficiency (DQE)

A. Nyquist frequency

If there were no contrast, the radiographic image would include.. A. Only the same shade of gray B. Black and white C. Light gray and dark gray D. Black and light gray

A. Only the same shade of gray

The part of the reader that senses the light released from the PSP plate is the.... A. Photodetector B. Optical system C. Drive mechanism D. Photostimulable luminescence

A. Photodetector

Each _____ is recorded as a single numeric value representing a single brightness level displayed on a monitor. A. Pixel B. Crystal C. Matrix D. None of these

A. Pixel

The Field of View (FOV) is determined by.. A. Size of detector B. Size of patient C. Anatomy of patient D. Bit depth

A. Size of detector

Greater resolution is a result of: A. Small pixels, large matrix B. Large pixels, small matrix C. Small pixels, small matrix D. Large pixels, large matrix

A. Small pixels, large matrix

One half of the nyquist frequency is equal to... A. The spatial resolution of the digital system B. The contrast resolution of a digital system C. The amount of noise in a digital system D. The detective quantum efficiency (DQE)

A. The spatial resolution of the digital system

The midpoint of the range of brightness levels visible on the digital image is determined by... A. Window Level B. Window Width C. Window Pane D. All of these

A. Window Level

The 3 rules of minimizing shape distortion are: (select 3) A. Part parallel to IR B. CR perpendicular to part C. Proper CR/Part/ IR relationship D. CR angled to IR

All but CR angled to IR

Ways to control motion include: A. Communication B. Minimize time C. Immobilizers D. Decrease kVp E. Sedation

All but kVp

The phosphor center in a PSP plate traps electrons in ________ with a ________ fluorescence when released. A. "F" center, green B. "F" center, blue violet C. "G" center, yellow D. "G" center, blue violet

B. "F" center, blue violet

The diameter of the input phosphor typically measures between.. A. 5 and 10 cm B. 15 and 30 cm C. 40 and 65 cm D. 75 and 100 cm

B. 15 and 30 cm

The diameter of the output phosphor is approximately.. A. 1 cm B. 2.5 cm C. 5 cm D. 25 cm

B. 2.5 cm

Following the detection of the light released from the phosphor layer, the amplified signal is sent to the ___________ to convert it to a digital electronic signal for the display computer. A. Digital-to-analog converter (DAC) B. Analog-to-digital converter (ADC) C. Light-to-computer device (LTC) D. None of these

B. Analog-to-digital converter

During laser beam formation, both ends of the laser reflect energy back and forth so that the atoms: A. Absorb each other B. Bombard each other C. Causes the laser beam to diverge D. Creates the laser beam

B. Bombard each other

Which of the following digital detectors continues to improve and can be used in mammography and dental radiography? A. Photostimulable phosphor (PSP) B. Complementary metal oxide semiconductor (CMOS) C. Light-to-computer device (LTC) D. Charged-coupled device (CCD)

B. Complementary metal oxide semiconductor (CMOS)

The visible difference between any two selected areas of brightness levels within the displayed radiographic image is... A. Density B. Contrast C. Spatial resolution D. Speed

B. Contrast

Increasing FSS= ____________ recorded detail (spatial resolution) A. Increased B. Decreased

B. Decreased

Which of the following combinations would result in an image with the least amount of magnification? A. Decreased OID and decreased SID B. Decreased OID and increased SID C. Increased OID and decreased SID D. Increased OID and increased SID

B. Decreased OID and increased SID

X-rays interact directly with a thin layer of amorphous selenium in.. A. Computed radiography B. Direct DR C. Indirect DR D. Digital fluoroscopy

B. Direct DR

The technique used to make underexposed areas darker and overexposed areas lighter is... A. Image inversion B. Equalization C. Image flip D. Aliasing

B. Equalization

The ratio of the number of light photons at the output phosphor as compared with the input phosphor is the... A. Brightness gain B. Flux gain C. Minification gain D. Conversion factor

B. Flux gain

Which of the following occurs when the OID is decreased? A. Image is magnified B. Image has greater spatial resolution C. Image is elongated D. Image is foreshortened

B. Image has greater spatial resolution

The electronic vacuum tube that converts the remnant x-ray beam to light, then to electrons, then back to light, increasing the light intensity in the process is the... A. X-ray tube B. Image Intensifier C. Recording system D. Mirror optics

B. Image intensifier

The more radiographers manipulate the data the _____ information the radiologist has to work with. A. More B. Less C. Once data is captured, it does not change D. Radiographers cannot manipulate the data

B. Less

Wide window width (WW) will be displayed as... A. Many densities, high contrast B. Many densities, low contrast C. Few densities, high contrast D. Few densities, low contrast

B. Many densities, low contrast

Failure of the reader to find the collimation edges of an image... A. Will result in image cutoff B. May cause the image to be too bright or too dark C. Will eliminate scatter D. Will have no effect on the resultant image

B. May cause the image to be too bright or too dark

When operated in magnification mode, the electrostatic lenses have ______ of a negative charge. A. Less B. More C. The same amount as usual D. One half

B. More

Following the laser stimulation of the PSP, the excited electrons are _______. A. Completely stabilized B. Mostly stabilized C. Still excited D. Completely removed

B. Mostly stabilized

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 silver-activated zinc cadmium sulfide. A. Input phosphor B. Output phosphor C. Photocathode D. Accelerating Anode

B. Output phosphor

Part of the direct capture DR system, the _______ absorbs x-rays and produces an electric signal. A. CCD B. Photoconductor C. TFT D. Scintillator

B. Photoconductor

Amorphous silicon is used as the.. A. Photoconductor for indirect capture DR imaging B. Photodetector for indirect capture DR imaging C. Photoconductor for direct capture DR imaging D. Photodetector for direct capture DR imaging

B. Photodetector for indirect capture DR imaging

The distance from the center of one pixel to the center of the one next to it is... A. Grayscale B. Pixel pitch C. Pixel density D. Contrast resolution

B. Pixel pitch

This part of the plate reflects light released during the reading phase toward the photodetector. A. Protective layer B. Reflective layer C. Phosphor layer D. Conductive layer

B. Reflective layer

With an INDIRECT radiography system, the ______ converts x-rays to light. A. Photodetector B. Scintillator C. Photomultiplier tube D. TV Camera

B. Scintillator

Objects that are being imaged can be misrepresented radiographically by the distortion of their shape. This is called.. A. Size distortion B. Shape distortion C. Sharpness distortion D. Size distortion and sharpness distortion

B. Shape distortion

Radiographers view the radiographic image in the ________ domain. A. Pixel location B. Spatial location C. DICOM D. EMR

B. Spatial location

What is used in the flat panel imaging system that absorbs x-rays and directly converts them into an electronic signal? A. Europium activated barium fluorohalide B. Amorphous silicon C. Amorphous selenium D. Scintillator

C. Amorphous selenium

The type of phosphor found in the PSP plate for computed radiography is... A. Plastic B. Amorphous selenium C. Barium fluorohalide D. Cesium iodide

C. Barium fluorohalide

The total number of shades of gray is determined by... A. Pixel B. Matrix C. Bit depth D. Field of View (FOV)

C. Bit depth

The ability of the imaging system to distinguish between small objects that attenuate the x-ray beam similarly is known as: A. Grayscale B. Spatial Frequency C. Contrast Resolution D. Brightness

C. Contrast Resolution

Which of the following creates the radiographic image without the use of light conversion? A. Computed Radiography (CR) B. Film/Screen C. Direct Digital Radiography D. Indirect Digital Radiography

C. Direct Digital Radiography

___________ imaging is used to view the human body in real time, accomplished with fluoroscopy as opposed to radiography. A. Static B. Still C. Dynamic D. Colorized

C. Dynamic

What refers to the range of exposure intensities an image receptor can accurately detect? A. Ionization B. Attenuation C. Dynamic Range D. Dynamic Imaging

C. Dynamic Range

A greater matrix size with the same FOV will have.. A. Less spatial resolution B. Matrix size and FOV are not related to spatial resolution C. Greater spatial resolution D. Larger pixels

C. Greater spatial resolution

In digital imaging, a decrease in brightness or window level indicates... A. Low contrast B. High contrast C. Increase in density from high pixel values D. Decrease in density from low pixel values

C. Increase in density from high pixel values

Making the digital image appear with low contrast, many shades of gray, is done by.... A. Raising the window level B. Lowering the window level C. Increasing window width (wide WW) D. Decreasing window width (narrow WW)

C. Increasing window width (wide WW)

The term that means an expression of the degree to which the image is made smaller from input phosphor to output phosphor is the.. A. Brightness gain B. Flux gain C. Minification gain D. Conversion factor

C. MInification gain

Collimation is _______ critical with digital imaging because it is ______ sensitive to scatter radiation. A. Less, less B. Less, more C. More, more D. More, less

C. More, more

Photoemission occurs at the... A. Input phosphor B. Output phosphor C. Photocathode D. Accelerating Anode

C. Photocathode

The __________ is bonded directly to the input phosphor. A. Input phosphor B. Output phosphor C. Photocathode D. Accelerating Anode

C. Photocathode

The ______________ in the image intensifier emits electrons when it is stimulated by light photons. A. Input phosphor B. Output phosphor C. Photocathode D. Electron gun

C. Photocathode

Amorphous selenium is used as the.. A. Photoconductor for indirect capture DR imaging B. Photodetector for indirect capture DR imaging C. Photoconductor for direct capture DR imaging D. Photodetector for direct capture DR imaging

C. Photoconductor for direct capture DR imaging

The number of pixels per unit area is.. A. Grayscale B. Pixel pitch C. Pixel density D. Contrast resolution

C. Pixel Density

The bit depth within a given pixel determines: A. Spatial resolution B. Field of View (FOV) C. Pixel brightness (gray level) D. Size of the voxel

C. Pixel brightness (gray level)

Which of the following contains a thin layer of pixels instead of a liquid crystal layer, with each pixel containing three neon and xenon gas-filled cells? A. Cathode ray tube monitor B. Liquid crystal display (LCD) monitor C. Plasma monitor D. Radiographic film

C. Plasma monitor

In digital radiography, the latent image is formed on the ________. A. Radiographic film B. Image matrix C. Radiation detector D. Computer screen

C. Radiation detector

When the electron beam sweeps the anode and travels back and forth across, from top to bottom, it is moving in a ________ pattern. A. Sweep B. Brush C. Raster D. Rooster

C. Raster

Correction of an exposure that is outside the range from either underexposure or overexposure by shifting the histogram to the correct area is: A. Sensitometry B. Quantum Mottle C. Rescaling D. Dynamic Range

C. Rescaling

A device that includes a photosensitive array and small pixels that converts light into electrical charges is known as a... A. Thin field transistor B. Field-effect C. Thin film transistor D. Field-energy

C. Thin film transistor

In an indirect capture DR system, the electronic components that is configured in a network of detector elements is the.. A. CCD B. Photoconductor C. Thin film transistor D. Scintillator

C. Thin film transistor

The image intensifier is located.. A. Next to the X-ray tube used for fluoro B. Beneath the x-ray table C. On a shelf just inside the room D. Inside the fluoroscopic tower

D Inside the fluoroscopic tower

The greatest number of shades of gray can be found in which bit depth? A. 2 B. 8 C. 10 D. 12

D. 12

Which of the following matrix's has the best resolution? A. 128x128 B. 512x512 C. 1024x1024 D. 2048x2048

D. 2048x2048

Shape distortion is caused by... A. Increasing OID B. Angling the X-ray tube C. Angling the patient D. Angling the X-ray tube and angling the patient

D. Angling the X-ray tube and angling the patient

Digital fluoroscopy is improved by using.. A. A vidicon camera B. Videotape C. A beam-splitting mirror D. A charged-coupled device (CCD)

D. A charged-coupled device (CCD)

The __________ is designed to set the electron stream in motion at a constant velocity, and is located very close to the output phosphor. A. Input phosphor B. Output phosphor C. Photocathode D. Accelerating Anode

D. Accelerating Anode

In digital imaging, exposure factors outside the desired range will cause.. A. Mottle B. Noise C. Patient overexposure D. All of the above

D. All of the above

The overall quality of the radiographic image is determined by.. A. Sharpness B. Visibility of anatomic structures C. Accuracy of structural lines D. All of these

D. All of these

Which of the following is true concerning direct capture DR imaging? A. The DR direct capture method does not use a scintillator B. The DR direct capture method uses a photoconductor and TFT array C. The DR direct capture method avoids the loss of resolution caused by indirect capture methods D. All of these are true

D. All of these are true

A pixel's _______ determines the amount of shades of gray that can be displayed in a digital image. A. Size B. Location C. Height D. Bit depth

D. Bit depth

In digital imaging, high pixel values will.. A. Increase image contrast B. Decrease image contrast C. Increase image brightness D. Decrease image brightness

D. Decrease image brightness

What impact does magnification have on distortion? A. Magnification does not influence distortion B. Increased magnification decreases distortion C. Decreased magnification increases distortion D. Decreased magnification decreases distortion

D. Decreased magnification decreases distortion

Making the digital image appear with high contrast, more black and white, is done by.. A. Raising the window level B. Lowering the window level C. Increasing the window width (wide WW) D. Decreasing the window width (narrow WW)

D. Decreasing the window width (narrow WW)

The radiographic misrepresentation of either the size (magnification) or the shape of the anatomic part is called... A. Brightness B. Contrast C. Sharpness D. Distortion

D. Distortion

The _________ is (are) found along the entire length of the image intensifier. A. Input phosphor B. Output phosphor C. Photocathode D. Electrostatic focusing lenses

D. Electrostatic focusing lenses

When the image of a structure appears longer than the actual structure, there is... A. Size distortion B. Foreshortening C. Magnification D. Elongation

D. Elongation

What important feature provides a numeric value indicating the level of radiation exposure to the digital image receptor? A. Optical density B. Detective Quantum Efficiency C. Modulation Transfer Function D. Exposure Indicator

D. Exposure Indicator

A radiographic image that has brightness levels that are very similar to each other... A. Has high contrast B. Has low contrast C. Has long-scale contrast D. Has low contrast and has long-scale contrast

D. Has low contrast and has long-scale contrast

After the image is retrieved, the PSP imaging plate is released by flooding it with intense ______ A. Electrical charge B. Heat C. Lasers D. Light

D. Light

What may happen when the digital image receptor is extremely over exposed? A. Excessive density B. Increased distortion C. Excessive contrast D. Saturation

D. Saturation

The image intensifier improved fluoroscopy by... A. Making the image easier to see because it's brighter B. Making the image easier to see because it's bigger C. Allowing indirect viewing of the fluoroscopic image D. Making the image easier to see because it's brighter and allowing indirect viewing of the fluoroscopic image

D. Making the image easier to see because it's brighter and allowing indirect viewing of the fluoroscopic image

When the PSP plate is exposed to the laser of the reader, the energy is released and converted to a digital signal, becoming a... A. Latent image B. Analog image C. Primary image D. Manifest image

D. Manifest image

A digital image is composed of a combination of rows and columns recorded as a: A. Dynamic Image B. Latent Image C. Pixel D. Matrix

D. Matrix

In digital imaging, high contrast is shown as... A. High window level B. Low window level C. Wide window width D. Narrow window width

D. Narrow window width

With an INDIRECT radiography system, the ________ converts light into an electronic signal. A. Photomultiplier tube B. Scintillator C. CCD D. Photodetector

D. Photodetector

At the time of processing, the energy of the trapped electrons is released by exposure to a laser in a process called.. A. Photodetector B. Scintillation C. Phosphorescence D. Photostimulable luminescence

D. Photostimulable luminescence

What digital characteristic affects the number of shades of gray available for image display? A. Pixel size B. Pixel density C. Pixel pitch D. Pixel bit depth

D. Pixel bit depth

Because digital systems are more sensitive to low-energy radiation, how can scatter radiation be effectively controlled? A. Pre-exposure collimation B. Post-processing masks C. Use of a grid D. Pre-exposure collimation and use of a grid

D. Pre-exposure collimation and use of a grid

Brightness fluctuations on the image is called.. A. Brightness B. Contrast resolution C. Spatial resolution D. Quantum noise

D. Quantum noise

Who evaluates the overall brightness on the image to determine if it is sufficient to visualize the anatomic area of interest? A. Patient B. Radiologist C. Supervisor D. Radiographer

D. Radiographer

Which of the following does NOT directly affect spatial resolution (recorded detail)? A. SID B. FSS C. OID D. Receptor exposure

D. Receptor Exposure

The ability to adjust the size of the FOV without exposing the patient to radiation is known as: A. Frame averaging B. Last image hold C. Digital subtraction D. Virtual collimation

D. Virtual collimation

Wide window with indicates: A. Increase in density B. Decrease in density C. Narrow latitude (short scale contrast) D. Wide latitude (long scale contrast)

D. Wide latitude (long scale contrast)

Flat panel detectors that use INDIRECT conversion technology convert.. A. Electrical signals to light B. Light to x-rays C. X-rays to electrical signals D. X-rays to visible light

D. X-rays to visible light

The input phosphor converts __________ to ___________. A. X-rays, electrons B. Light, electrons C. Electrons, light D. X-rays, light

D. X-rays, light

Bit depth does which of the following? A. Determines the amount of precision in digitizing the analog signal B. Determines the exact pixel brightness C. Determined by the analog-to-digital converter D. Ranges from 8 bits to 32 bits E. All of the above

E. All of the above

Which of the following is an advantage of flat panel detectors used in fluoroscopy? A. Much higher and more compact B. Produce a digital signal directly C. Less electronic noise D. 60x larger operational dynamic range because they don't exhibit veiling glare E. All of these

E. All of these

(T/F) A look-up table (LUT) replaces the need for a radiographer to know exact mA, time, and kVp for each procedure because rescaling is available.

False

What is the formula for magnification?

IW/OW= SID/SOD

Spatial resolution can be increased by.. 1. Increasing the pixel pitch 2. Increasing the pixel density 3. Decreasing the pixel pitch

Increasing the pixel density and decreasing the pixel pitch only