MI208

The _____ converts X-ray energy directly to a Digital electrical signal:

a. photoconductor

b. photomultiplier

c. scintillator

d. TLD

a. photoconductor

The acronym PACS stands for:

a. picture archival computer system

b. picture archiving & communication system

c. picture arrangement communication system

d. none of the above

b. picture archiving & communication system

the number of bits per pixel is known as bit:

a. pitch

b. depth

c. height

d. width

b. depth

a greater # of pixels in a given area of the matrix is defined as:

a. pixel depth

b. pixel area

c. pixel density

d. pixel pitch

a. pixel depth

if a pixel has a bit depth of 8, the number of gray tones that pixel can produce is:

a. 256

b. 512

c. 1024

d. 2500

a. 256

in a DR system, which of the following are needed to produce a radiographic image?

a. xray absorber and a CCD

b. intensifying screen and a TFT

c. storage phosphor plate and a CCD

d. storage phosphor plate and a TFT

a. xray absorber and a CCD

each square in a matrix is called a:

a. matrix element

b. picture element

c. bit

d. byte

d. picture element

each box within an image matrix corresponds to:

a. analog signal

b. a specific area of the patients tissue

c. mAs value

d. kVp value

b. a specific area of the patients tissue

T OR F: As signal to noise ratio (SNR) increases patient exposure decreases

False

The size of the pixel is determined by the:

a. bit

b. bit depth

c. matrix

d. byte

c. matrix

T or F: DICOM is a standard that allows imaging modalities and PACS to communicate in the same language.

True

The measurement for radiation that was incident on the image receptor for a particular exposure is known as:

a. Gy

b. KSTD

c. KIND

d. KTGT

c. KIND

the two elements that can convert light into an electrical signal while using indirect capture DR:

a. photodiodes (CCD or TFT)

b. photoconductors (TTF or CDD)

c. phototransistors (ADC or DAC)

d. none of the above

a. photodiodes (CCD or TFT)

factors that can adversely affect the pixel values expressed in the deviation index include all of the following except:

a. gonadal shielding within the image

b. a prosthesis within the image

c. failure of the system to recognize the exposure indicator

d. failure of the system to recognize the collimated border

c. failure of the system to recognize the exposure indicator

when using the CR _____ generates the latent image:

a. kVp

b. mAs

c. casette

d. imaging plate

d. imaging plate

T or F: exposure indicator in CR system is measured by the Dose Area Product (DAP) meter embedded within the collimator:

false

pixel pitch is defined as:

a. distance measured from the top of the pixel to the bottom of the pixel

b. distance measured from the center of a pixel to an adjacent pixel

c. distance measured from the left of the pixel to the right of the pixel

d. distance measured from the top corner of the pixel to the bottom corner of the pixel

b. distanced measured from the center of a pixel to an adjacent pixel

The ability of an imaging system to demonstrate small details of an object is known as:

a. image quality

b. contrast resolution

c. spatial resolution

d. dynamic range

c. spatial resolution

T or F: indirect capture DR converts absorbed xray energy into visible light

true

the efficiency of a system to convert xray input signal into a useful output image is known as:

a. dynamic range

b. spatial resolution

c. latitude

d. defective quantum efficiency

d. defective quantum efficiency

xray energy related to direct capture DR will stimulate a ____, which eventually is changed into an electrical signal

a. photodensitometer

b. scintillator

c. TFT array

d. charge-coupled device

b. scintillator

the range of exposure values the image detector is able to produce is known as:

a. dynamic range

b. modulation transfer

c. latitude

d. detective quantum

c. latitude

critical characteristics of a digital image include all of the following except:

a. spatial resolution

b. noise

c. sampling resolution

d. dose efficiency of the receptor

c. sampling resolution

the 2 distinct steps of analog to digital conversion (ADC) are:

a. sampling and conversion

b. scanning and sampling

c. sampling and quantization

d. scanning and quantization

c. sampling and quantization

T or F: changes in FOV affect matrix size

false

T or F: to raise a DI by 1 raise exposure by 50%

false

the main distinction between CR and DR is:

a. direct connection between the exposure and processing units

b. indirect connection between the exposure and processing units

c. speed of image acquisition

d. speed of image delay

a. direct connection between the exposure and processing units

a perfect image processing system would have an MTF of:

a. 1%

b. 10%

C. 100%

D. 1000%

C. 100%

T or F: changes in matrix size affect pixel size

True

the ability of a digital system to display subtle changes in shades of gray is called:

a. image quality

b. contrast resolution

c. spatial resolution

d. dynamic range

b. contrast resolution

the xray absorber typically used in direct capture DR is a:

a. photodiode

b. phototransistor

c. photoconductor

d. photoelectron

c. photoconductor

storage phosphor plates ____ store energy representing the image signal

a. temporarily

b. constantly

c. never

d. sometimes

a. temporarily

PACS communicates with the following:

a. RIS, HIS, teleradiology

b. RIS, HIS, table bucky

c. RIS, HIS, wall bucky

d. Reading stations, wall Bucky, table Bucky

a. RIS, HIS, teleradiology

the overall dimension of the image matrix is defined as:

a. pixel

b. voxel

c. IR size

d. FOV

d. FOV

“the ability of a system to record available spatial frequencies and pass them to the final image” is the definition of:

a. modulation transfer function (MTF)

b. enhanced visitation image processing

c. digital image contrast and density latitude

d. principles of contrast enhancement

a. modulation transfer function (MTF)

compared with a 90 second processing time found in film screen radiography, the time from image acquisition to display with DR is:

a. instantaneous

b. there is no difference

c. faster

d. slower

instantaneous

which of the following statements is not true:

a. matrix size can change without affecting the FOV

b. FOV can change without affecting the matrix

c. changing he matrix or the FOV will change the size of the pixel

D. changing the matrix and the FOV will not change the size of the pixel

d. changing the matrix and the FOV will not change the size of the pixel

T or F:In digital imaging: both CR and DR respond to exposure slower than film screen radiography:

false

the 3 types of noise that are concern in digital imaging are:

a. spatial noise, quantum mottle, dark noise

b. system noise, ambient noise, quantum mottle

c. dark noise, ambient noise, system noise

d. background noise, ambient noise, quantum noise

b. system noise, ambient noise, quantum mottle

deviation is the difference between -- and -- expressed in logarithmic fashion:

a. actual exposure (KIND) and target exposure (KTGT)

b. standard exposure (KSTD) and actual exposure (KIND)

c. standard exposure (KSTD) and target exposure (KTGT)

a. actual exposure (KIND) and target exposure (KTGT)

CR acquires an image through":

a. conventional film/screen processing using a digital canner

b. the heating of a thermoluminescent device

c. an electrically charged cassette

d. the use of a photostimuable phosphor plate

d. the use of a photostimuable phosphor plate

the main function of a PACS system is:

a. assigns an accession # to each image

b. assigns an MR # to each image

c. acts as a file room

`d`. acts as a data base

`d`. acts as a data base

which of the following statements is not true:

a. exposure index refers to the amount of exposure to the patient

b. exposure index refers to the amount of exposure to the image receptor

c. exposure is not uniformly represented across manufactures

d. exposure index standardization is beneficial to the technologist

a. exposure index refers to the amount of exposure to the patient

T or F: air kerma is the measurement of radiation energy absorbed in a unit of air

true

with conventional radiography optical density is a primarily controlled by:

a. kilovoltage

b. milliamperage

c. line voltage

d. milliampere-seconds

d. milliampere-seconds

the relationship between pixel size and resolution is:

a. inversely proportional

b. directly proportional

c. there is no relationship

d. none of the above

a. inversely proportional

multiple numeric values directed into an array of small elements capable of being processed is the definition of ___ images:

a. analog

b. digital

c. medical

d. radiographic

b. digital

how efficiently a system converts the xray input into a useful output image is known as:

a. exposure latitude

b. dynamic range

c. modulation transfer function (MTF)

d. detective quantum efficiency (DQE)

d. detective quantum efficiency (DQE)

the ability to distinguish small structures from background and noise is known as:

a. spatial resolution

b. contrast resolution

c. detail inclusion

d. digital view

a. spatial resolution

how dark or light a digital image appears on a display monitor is known as:

a. density

b. contrast resolution

c. brightness

d. spatial resolution

c. brightness

defective pixels can result from all of the following except:

a. chemical corrosion

b. static discharge

c. software programs

d. age

c. software programs

scintillators are phosphors that:

a. produce light when absorbing xrays

b. produce X-rays when absorbing light

c. absorb light and produce electrical charges

d. absorb xrays and produce electrical charges

a. produce light when absorbing xrays

when the imaging plate is irradiated, stimulated electrons enter the ____ layer:

a. active

b. conductive

c. protective

d. support

a. active

which of the following can be done to decrease the chance of having image lag occur in the next image?

a. decrease the amount of time between exposures

b. increase the amount of time between exposures

c. leave collimation open

d. acquire the image requiring the highest technical factors first

b. increase the amount of time between exposures

the 2 types of PSP readers are:

a. single scan and multiscan

b. fast scan and slow scan

c. line scan and point scan

d. none of the above

c. line scan and point scan

unstructured (turbid) photo phosphors in direct conversion detectors:

a. absorb and reduce static

b. gives the imaging sheet strength

c. protects the back of the cassette

d. produce more scattered light

d. produce more scattered light

flat panel detectors that can use indirect conversion technology convert:

a. electrical signals to light

b. light to xrays

c. xrays to electrical signals

d. xrays to visible light

d. xrays to visible light

which of the following does not determine PSP resolution?

a. phosphor layer thickness

b. pixel size

the number of pixels

d. laser scan speed

d. laser scan speed

TFT flat panel detectors were first introduced in what year?

a. 1991

b.1997

c.1995

d.1992

c.1995

which of the following is used as a photoconductor?

a. gadolinium oxysulphide

b. amorphous selenium

c. amorphous silicon

d. cesium iodide

b. amorphous selenium

PSP (CR) imaging plates are erased by flooding the plates with:

a. light

b. radiation

c. electrons

d. phosphors

a. light

T or F: each pixel in a DR detector contains 2 sensing components

true

T or F: PSP (CR) imaging plates are capable of storing images:

true

the higher the number of pixels in a matrix, the:

a. higher the image resolution

b. lower the image resolution

c. lack of effect on image resolution

d. smaller the image

a. higher the image resolution

which of the following serves to protect against static build up, dust collection, and mechanical damage to the imaging plate?

a. aluminum backing

b. lightweight plastic

c. felt material

d. cassette front

c. felt material

cracks in the imaging plate can be caused by:

a. excessive kVp

b. removing and replacing the plate in the reader

c. improper eraser

d. scatter through the back of the cassette

b. removing and replacing the plate in the reader

the conversion type in DR (direct vs indirect is determined by:

a. spatial resoluiton

b. absorption material

c. DQE

d. SNR

b. absorption material

Which of the following is not considered a scintillator?

a. gadolinium oxysulphate

b. cesium iodide

c. amorphous selenium

d. none of the above

c. amorphous selenium

the amount of detail present in any image is known as ___ resolution:

a. contrast

b. density

c. spatial

d. optical

c. spatial

intermittent extraneous line patterns are ____ artifacts

a. imaging plate

b. plate reader

c. image processing

d. printer

b. plate reader

the purpose of the barcode label or identification of an IR is to match the image information with the:

a. imaging plate

b. patient (accession #)

c. technologist

d. radiographic room

b. patient (accession #)

grid use for PSP examination is more critical than in film/screen radiography because CR:

a. examinations produce more scatter

b. imaging plates are extremely sensitive to scatter

c. imaging plates record less scatter

d. examinations requires much higher kvp values

b. imaging plates are extremely sensitive to scatter

more than 1 million pixels can be converted to a digital image in less than:

a. 1 hour

b. 1 millisecond

c. 1 second

d. 1 minute

c. 1 second

when discussing PSP (CR) during the reading process the imaging plate in older systems is scanned with a _____ laser beam, which is the equivalent of a solid state laser diode in more recent systems

helium

T or F: spatial resolution is the only way to measure detector performance:

false

a detector in which each pixel has its own amplifier is known as a:

a. CCD

b. field effect transistor

c. CMOS

d. thin field transistor

a. CCD

T or F: gadolinium oxysulphide detectors have reduced efficiency as compared to cesium iodide detectors

true

possible causes of image lag include all EXCEPT:

a. rapid succession images

b. overexposure

c. lack of beam attention

d. underexposure

d. underexposure

each light photon is assigned a numerical value during:

a. amplificaton

b. sampling

c. digitization

d. laser scanning

c. digitization

the process of scanning the moving imaging plate is known as:

a. transition

b. raster scanning

c. digitization

d. translation

d. translation

the exposure indicator number is:

a. an accurate measure of the patient dose

b. an indication of radiation absorbed by the imaging plate

c. both a and b

d. neither a nor b

b. an indication of radiation absorbed by the imaging plate

indirect conversion in flat-panel detector is a ___ step process

a. one

b. two

c. three

d. four

b. two 

T or F: vertical white lines on images may be caused by dirt on the light guide in the plate reader

false

when utilizing PSP (CR) and DR kilovoltage peak (kVp) should be chosen:

a. to provide etch lease contrast possible

b. to provide penetration

c. for the type and amount of contrast desired

d. for the type of imaging plate phosphor

b. to provide penetration

T or F: The PSP imaging plate does not require periodic erasure because of its ability to record background radiation:

False

T or F: cesium iodide is considered and unstructured scintillator

false

backscatter created by xray photons transmitted through the back of the IR can cause:

a. have no effect on image quality

b. mottle

c. dark line artifacts

d. white line artifacts

c. dark line artifacts

photoconductors are materials that:

a. produce light when absorbing xrays

b. produce xrays when absorbing light

c. absorb light and produce electrical charges

d. absorb xrays and produce electrical charges

d. absorb xrays and produce electrical charges

cesium iodine is considered an unstructured scintillator

false

the laser scans the imaging plate in a ___ pattern

a. raster

b. horizontal

c. circular

d. random

a. raster

which of the following should be considered when selecting the PSP (CR) cassette?

a. size and speed

b. type and speed

c. size and type

d. none of these

c. size and type

when specialized pixels in a complementary metal oxide silicon system are struck with xray photons

a. the xray photons are converted into light

b. light photons are stored in capactiors

c. light photons are converted into electrical charges

d. all of the above

c. light photons are converted into electrical charges

T or F: all flat panel detector systems have the ability to take images faster than the detector can accommodate

false

The PSP (CR) casette is backed by aluminum or lead that:

a. reflects xrays

b. absorbs backscatter xrays

c. captures the image

d. transmits xrays

b. absorbs backscatter xrays

which of the following flat-panel detector technologies was developed by NASA?

a. CCD

b. field effect transistor

c. CMOS

d. thin-field transistor

c. CMOS

when insufficient light is produced by the imaging plate phosphor, the image will:

a. not be formed

b. be grainy

c. be dark

d. be detailed

b. be grainy

all of the following statements are true except:

a. direct conversion DR uses a photoconductor

b. photoconductors are typically made of a-Se

c. the sensing component in direct conversion is a capacitor

d. direct conversion is a 2 step process

d. direct conversion is a 2 step process

flat panel detectors that use indirect conversion technology convert:

a. electrical signals to light

b. light to xrays

c. xrays to electrical signals

d. xrays to visible light

d. xrays to visible light

the optimum range of kVP to be used with PSP systems is:

a. 60-110

b. 55-130

c. 65-120

d. 75-130

a. 60-110

when utilizing PSP (CR) or DR milliampere-seconds (mAs) is selected for the:

a. shortest time possible

b. longest time possible

c. number of electrons needed

d. amount of penetration needed

c. number of electrons needed