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Flux gain is a measurement of the increase in light photons caused by conversion efficiency of the:
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The highest energy scatter from the pt during fluoroscopy occurs at a ____ degree angle from the incident beam.
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Parker-Final
MidTerm, Quiz 3 & 4
| Question | Answer |
|---|---|
| Flux gain is a measurement of the increase in light photons caused by conversion efficiency of the: | Output screen |
| The highest energy scatter from the pt during fluoroscopy occurs at a ____ degree angle from the incident beam. | 90 |
| The minimum source to skin distance is ____ for stationary fluoroscopic equipment. | 15" |
| Fluoroscopic mA range is commonly ____ mA. | 0.05 to 5 |
| During fluoroscopic image intensification, the primary x-ray beam exits the pt & strikes the ______ of the image intensifier. | input screen |
| The photocathode absorbs ________ & emits _________. | light photons; electrons |
| The output screen absorbs _______ & emits _________. | electrons; light photons |
| The input screen is ______ in shape. | concave |
| Mobile chest radiography should be performed w/the pt: | semi-erect |
| T/F: Mobile units produce an x-ray beam w/an average photon energy that is quite similar to that of a stationary unit. | False |
| During mobile radiography, a ________ grid is used which leads to increase latitude. | parallel |
| Mobile exams are difficult to accomplish because: | there are so many additional variables |
| During mobile radiography, the radiographer must achieve maximum distance from the: | patient |
| The more advanced full power mobile units use __________ energy for a power supply. | battery |
| The human eye is anatomically designed to do all except the following: 1. Focus light 2. Transmit nervous impulses 3. Analyze density differences 4. Gather light | C. Analyze density differences |
| Which of the following is associated w/night vision? | Scotopic vision |
| How many cones are located in the human eye? | 7,000,000 |
| The __________ effects occur because the visual system has difficulty perceiving contrast differences that are distance from one another. | boundary |
| Visual acuity in daylight & changes in brightness are better due to: | Cones |
| What has an impact on the amount of scatter produced from the irradiated material? | atomic number |
| The purpose of the upper shutter in the collimator is to: | reduce stem radiation |
| In radiography, kilovoltage is determined more on the size of the part being x-rayed & the: | contrast desired |
| One of the disadvantages of a collimator is it: | high cost |
| What affects the penetrability of the beam? | kVp |
| Collimators are restricted in their use for low-level radiation procedures such as: | mammography |
| When an intense bright light from a view box floods the eye directly, this is known as: | veil glare |
| Another name for automatic collimatore is: | Positive beam limitation devices |
| Which of the following was the original type of beam restictor? | aperture diaphragm |
| Digital imaging is a broad term; the term was first used medically in 1970s in: | Computed Tomography |
| All of the following is true regarding Digital Radiography except: 1. Cassetteless sys 2. Uses a flat panel detector or charge-coupled device (CCD) hard-wire to computer 3. Requires new installation of room or retrofit 4. Requires special cassettes | Requires special cassettes |
| There are 2 types of digital radiography, what are they? | Indirect & direct |
| When comparing film to CR & DR, which of the following is more efficient & the image is available immediately: | DR |
| Most storage phosphor plates are made of: | Barium fluorohlide |
| With CR & DR, concerning exposure latitude; kilovoltage peak still influences subject contrast, but radiographic contrast is primarily controlled by an: | Image processing look-up table |
| With CR & DR, concerning exposure latitude; milliampere-second setting has more control over image noise, but radiogrphic density is primarily controlled by an: | Image processing algorithms |
| T/F: CR & DR can be more sensitive to scatter than screen/film. | true |
| Picture Archival & Communication Systems are costumed designed for each facility & is based on 4 components, which is NOT on of them? 1. funding 2. storage space 3. volume of pt 4. viewing locations | storage space |
| Machine absorbs x-rays & converts them to light. CCD or thin-film transistor (TFT) converts light to electric signals. Computer processes electric signals. Images are viewed on computer monitor. All of these attributes describe which system? | Indirect Capture |
| Which of the following handles data of continuous currents? | analog |
| Concerning the Central Processing Unit of a computer, which of the following is less expensive & needs more transmission time or is slower? | serial |
| If you turn off the power to your computer, which one of the following concerning memory is erased? | RAM - Random Access Memory |
| This is a special computer that functions as a peripheral that uses CPU memory to simultaneus math problems in a parallel fashion instead of performing them sequentially & is very useful when vast #s of repetitive calculations are required. | Array processor |
| There are many types of detectors; which is not on of them? 1. Radiation 2. Nuclear medicine 3. Ultrasound 4. Radiofrequency | 2. Nuclear Medicine |
| Concerning digital image acquisition; which of the following determines resolution? | Pixel size |
| Which of the following ensures all equipment speaks the same language even though there are different manufacturers? | Digital Imaging & Communication in Medicine (DICOM) |
| Which of the following is the process of returning the pixel values to their original level by a reverse process? | Deconvolution |
| When discussing the display qualities; window level controls the image: | density |
| When discussing the display qualities; window width controls the image: | contrast |
| This type of filtering either amplifies/deletes all but low frequencies, reduces image noise & often used to remove high frequency noise (smoothing). | low pass |
| Concerning digital image quality, a measure of total amount of contrast in the image is known as: | frequency |
| The CR cassette is backed by aluminum that: | absorbs x-rays. |
| Which one of the following serves to protect against static buildup, dust collection, & mechanical damage to the imaging plate? | felt material |
| The layer of the imaging plate that traps electrons during exposure is the _________ layer. | active |
| The imaging plate layer that absorbs stimulating light & reflects emitted light is the _______ layer. | color |
| The purpose of the barcode label is to identify the: | imaging plate |
| The signal trapped in the phosphor center: | is never completely lost |
| T/F: Lasers create & amplify wide, soft beams of divergent light. | false |
| During laser beam formation, both ends of the laser reflect energy back & forth so that the atoms: | bombard each other |
| Coherent light formed by the laser because the photons: | travel in the same direction |
| The optical mirror in the reader: | directs the laser beam to the imaging plate surface |
| The device that moves the laser rapidly back & forth across the imaging plate is known as: | Beam optics |
| Typical cassette throughput is: | 50 cassettes/hour |
| The power source for laser must be: | constant |
| The laser scans the imaing plate in a ______ pattern. | raster |
| The process of scanning the moving imaging plate is known as: | translation |
| Which of the followign does not determine CR resolution? | Laser scan speed |
| T/F: CR phosphor speed & radiographic film speed are always equivalent. | false |
| Imaing plates should be erased every: | week |
| CR imaing plates are erased by flooding the plate with: | light |
| Each square in a matrix is called a: | picture element |
| The # of bits per pixel is known as bit: | depth |
| The amount of detail present in any image is known as ________ resolution. | spatial |
| T/F: Cassette-based spatial resolution is lower than conventional radiography. | true |
| The imaging plate reader uses a laser to scan the imaging plate, releasing the energy stored in the conductive layer as ______ light. | blue |
| Images that can be displayed on a monitor are known as: | soft copy |
| There are 2 systems available for digitizers, one is the CCD Linear array & the other is: | Laser |
| The size of an image is dependent upon the bit depth & : | matrix size |
| What is the anticipated image file size for a computed radiography digital image comprised of a 2,500x2,500 matrix w/a 16 bit depth? | XY(B/8) |
| What controls the speed at which data can be sent over a network & is measured in bits per second? | bandwidth |
| A __________ connects all computers in a system & often uses ethernet that can have a bandwidth of 10Mbas _________ light. | LAN Local Area Network |
| Which of the following sends the image and pt data to the radiologist/clinician? | PACS - Picture Archiving and Communication System |
| There are 3 light sources for laser printers, which is NOT one of them? 1. infrared 2. helium-neon 3. barium luminescence 4. solid state diode | barium luminescence |
| Wet laser film contain silver halides & is spectrally sensitive to infrared or _______ wavelengths. | red |
| Concerning dry processor, the film could potentially continue to develop density if exposed to high heat conditions, which is known as: | print-up |
| Which of the following storge type has a local hard drive, PACS server & RAID Redundant Array of Independent Disks? | Short term |
| ________ ________ contains information about the study & the pt. | Object class |
| The combination of service, such as imaging storage w/an object such as a CT exam is considered an: | Service Object Pairs |
| There are many difficulties w/a PACS system, which is not one of them? 1. small files 2. limited bandwidth 3. special language 4. problems interfacing w/HIS | small files |
| T/F: Unexposed dry-processing laser film has a shorter shelf life than conventional film. | true |
| _________ class decribes what to do with the objects. | Service |
| Failure of the reader to find the collimation edges of an image: | may cause the image to be too bright or too dark |
| If the entire range of exposure were digitized, pixel values representing _____ would be digitized. | all values |
| Data collected w/in the collimator are represented by a ___________. | histogram |
| A histogram displays the useful signal by locating: | Maximum & minimum signal |
| The higher the kilovoltage peak, the: | narrower the histogram |
| T/F: The shape of the histogram is anatomy specific. | true |
| The Nyquist theorem states that the: | sampling frequency must be more than twice the imput signal bandwidth |
| If too few pixels are sampled, the result will be: | low resolution |
| Loss of detail in a digitally processed image: | occurs because of the # of conversions |
| The longer an image is stored in the CR cassette, the: | more energy is lost by electrons |
| In an effort to display the pixels for the area of interest when exposure is greater or less than what is needed to produce an image, __________ occurs. | automatic rescaling |
| Automatic rescaling means that images are produced, regardless of the amount of exposure, with: | uniform contrast & density |
| T/F: Automatic rescaling can be substituted for appropriated technical factors. | false |
| The amount of error that can be made & still result in tha capture of a quality image refers to: | latitude |
| T/F: Exposure latitude for digital imaging is less than that of film/screen imaging. | false |
| "The sum of the components in a recording system cannot be greater than the system as a whole" is a defintion of: | modulation transfer function (MTF) |
| A perfect image processing system would have an MTF of: | 1% or 100% |
| T/F: It is possible to achieve an MTF of 100%. | false |
| The more light spread, the (lower or higher) ________ the MTF. | lower |
| If all of the shades were left in an image after processing, the contrast would be: | too low |
| The more manipulation of the image, the greater the: | loss of information |
| Amplification of the frequencies of the areas of interest is known as: | edge enhancement |
| Suppressing frequencies in the areas of interest is known as: | masking |
| Low-pass filtering is also known as: | smoothing |
| High-pass filtering is useful for enchancing: | organs & soft tissue |
| Averaging the frequency of each pixel w/surrounding pixel values to remove high-frequency noise is called: | smoothing |
| Excessive light entering the eye when viewing an image is known as _________ glare. | veil |
| An image manipulation process that fills in the background so that it is darkened is known as: | shuttering |
| T/F: Shuttering removes the dark exposed border, reducing the amount of information to be stored. | false |
| The process of joining 2 or more images into 1 continuous image is known as image: | stitching |
| The workstation function that allows selection of preset terms and/or manual text input is termed image: | annotation |
| Magnification of the entire image at the workstation is termed: | macroradiography |
| The ability to send images to local network stations can be accomplished using the: | manual send function |
| Aliasing results in a ________ effect. | Moire |
| If too few pixels are sampled, the result is a lack of: | resolution |
| In CR, if exposure is more than _______% below the ideal exposure, quantum mottle results. | 50 |
| Sharpness control is referred to as: | spatial frequency control |
| The more ________ involved in the averaging, the smoother the image appears. | pixels |
| If exposure is more than 200% above ideal exposure, _________ __________ results. | contrast loss |
Created by:
e_ortiz79