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185 Cards in this Set
- Front
- Back
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Which radiographic image capture method uses chemical development to produce the manifest image |
Film/screen radiography |
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Which company was the first to introduce PSP imaging commercially in the US |
Fuji |
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Which radiographic image capture method uses an x-ray absorber material coupled to a thin film transistor or a charged coupled device to form a digital radiographic image |
FPD |
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PACS stands for |
Picture archival communication system |
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Film and intensifying screens are primarily used in |
Conventional radiography |
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What format must the images be in order to be sent throughout the imaging viewing system |
DICOM |
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The first commercial CT scanners could only image the |
Head |
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Who was the first to incorporate digital imaging with the CT scanner |
Godfrey Hounsfield |
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What is teleradiology |
moving images via telephone lines to and from remote locations |
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Who first conceptualized teleradiology |
Albert Jutras |
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When was the first MRI introduced |
1980's |
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Any image acquisition process that produces an electronic image that can be viewed and manipulated on a computer |
digital imaging |
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What year did Hounsfield invent the CT scanner |
1970 |
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Indirect capture radiography |
absorbs x-rays and converts then into light, light then converted to electrical signal using CCD and TFT, and that is then sent to the computer |
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Direct capture radiography |
x-ray is converted directly into an electrical signal, then to a TFT and then to the ADC to send it to the computer |
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When was the first PACS installed |
1993 |
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Compared with a 90 second processing time found in conventional radiography, image acquisition with DR has now been reduced to |
3 to 5 seconds |
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T/F: Technologist efficiency ratings are generally the same when comparing conventional radiography with PSP/CR radiography? |
True |
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The active element in a storage phosphor is |
Barium Fluorohalide |
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With conventional radiography, optical density is primarily controlled by |
mAs |
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A standard that allows imaging modalities and PACS to communicate in the same language |
DICOM |
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Examples of preset image annotation controls
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Arrows, position indicators, image acquisition markers |
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An image formed by recording a continuous changing signal is known as |
analog |
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The arrangement of pixels in rows and columns is known as |
matrix |
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The amount of tissue included in the image is referred to as |
field of view |
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the measurement of the radiation that was incident on the image receptor for a particular exposure is known as |
K(ind) |
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The difference between the actual exposure and the target exposure is know was |
DI |
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Contrast resolution is a digital systems ability to |
Show small differences in gray levels |
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Ability of a digital imaging system t respond to varying levels of exposure |
Dynamic Range
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The smaller the pixels, what effect is had on resolution |
the better the resolution |
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measures the efficiency of a system to convert the x-ray input signal into a useful output image |
DQE |
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Images that are recorded as multiple numeric values that are recorded |
digital image |
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the number of bits within a pixel |
pixel bit depth |
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How big can a matrix get |
2500 X 2500 |
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K(std) |
A standard exposure typical of that imaging receptor system |
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K(tgt) |
A set of values that represents an optimal exposure for each specific body part or view |
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If the DI is negative, the image has been ____________ |
underexposed |
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If the DI is positive, the image has been ___________ |
overexposed |
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How do you raise your DI +1? |
increase technique 20% |
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How do you decrease your DI by -1 ? |
decrease technique by 25% |
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Ability of the imaging system to demonstrate small details of an object |
spatial resolution |
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A graphical representation of a digital image is called a |
histogram |
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The useful signal is determined during which part of the imaging cyle |
image sampling |
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Nyquist Theorem |
The sampling frequency must be less than twice the frequency of the input signal |
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What occurs when the sampling frequency is not greater than twice the frequency of the input signal |
aliasing |
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In digital projection radiography, what process is used to normalize an image that has been taken with too great of an exposure |
Automatic rescaling |
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T/F : the look-up table that is used to determine brightness and contrast of an image is unique for each anatomic part? |
True |
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Which processing technique will amplify particular known frequencies in an image while suppressing others |
Edge enhancement |
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Controls the brightness of the image on the display |
Window width |
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Will put together multiple images into one single image for display |
Image stitching |
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Which of the following serves to protect against static build up, dust collection, and mechanical damage to the imaging plate |
Felt material |
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The layer of the imaging plate that traps electrons during exposure |
Active layer |
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Sends light in a forward direction |
Reflective Layer |
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The phosphor layer is made of phosphors from what family |
barium fluorohalide |
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During laser beam formation, both ends of the laser reflect energy back and forth so that the atoms |
bombard each other |
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Coherent light is formed by the laser because the photons |
travel in the same direction |
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Optical Mirror |
directs the laser beam to the imaging plate surface |
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The laser scans the imaging plate in what pattern |
raster |
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PSP imaging plates are erased by flooding the plate with |
light |
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Color layer |
Absorbs the stimulating light but reflects the emitted light |
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Fast scan direction |
Movement of the laser across the imaging plate |
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Slow scan direction/ translation |
The movement of the imaging plate through the reader |
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What does laser stand for |
light amplification of stimulated emission of radiation |
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Quantum mottle results from |
not enough mAs |
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If grid lines are present and run parallel to the scanning laser, the image will result in |
the moire pattern |
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Absorbs x-rays and produced electrical charges |
Photoconductor |
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Used to correct flaws in the detector |
gain calibration |
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In direct conversion, what is the radiation-conversion material typically made of ? |
Amorphous selenium |
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What are the type of phosphors used in indirect conversion detectors |
Amorphous silicon with Gadolinium oxysulfide or cesium iodide |
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Gadolinium oxysulfide forms what type of scintillation layer |
unstructured |
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Cesium iodide is considered what type of scintillator |
structured |
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What is another term for unstructured layer |
Turbid |
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The purpose of the barcode label is to match the image information with |
the patient |
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When the imaging plate is irradiated, stimulated electrons enter what layer |
Active |
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Each light photon is assigned a number during |
digitization |
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the process of scanning the moving imaging plate is known as |
Translation |
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kVp should be chosen to |
provide penetration |
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mAs is chosen for |
number of electrons needed |
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When insufficient light is produced by the imaging plate phosphor, the image will be |
grainy |
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Scintillators are phosphors that |
Absorb x-ray photons and emit light |
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Use thin crystalline needles, very little light spread |
CSI detectors |
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The oldest indirect conversion technology used in a variety of image capture applications |
charged-coupled device |
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When voltage gates close, it (allows/stops) the flow of electrons? |
allows |
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Common types of noise affecting image quality |
Statistical noise, "dark" current noise, and amplification noise |
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Dopants |
turn semi conductors into full electrical conductors |
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A programmable device that can store, retrieve, and process data |
Computer |
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How many bits are in a single Byte |
8 |
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What keeps the radiofrequencies generated within the computer electronics from interfering with outside devices |
the case |
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What is the largest circuitry board inside the computer |
Motherboard |
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What device runs the startup instructions during boot-up of the computer |
BIOS |
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Which is the most versatile port found on a computer |
USB |
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What type of monitor is most common in hospitals? |
LCD |
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If the transistor circuit is closed, allowing current to pass through, it is assigned a value of |
1 |
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What are the functions of the computer encasement |
1. Holds all components In a cool, clean, safe environment2. Shields the outside environment from radio frequencies being emitted by the computer |
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Two major configurations of a computer |
horizontal and tower |
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the BUS |
a series of connections, controllers, and chips that creates the information highway of the computer |
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What are the two major types of monitors |
CRT or LCD |
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Dot triad |
A grouping of one red dot, one green dot, and one blue dot |
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The measurement of how close the dots are located to one another within a pixel |
Dot pitch |
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Three major operating systems |
1. Macintosh OS 2. Windows my Microsoft 3. UNIX/Linux |
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Modern PACS uses what type of Operating system |
windows |
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Network |
Two or more objects sharing resources and information |
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Network classifications based on geographic location |
LAN, WAN, MAN |
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On a server-based network, is each computer considered equal? |
no |
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Which type of network does the centralized computer have control over the entire network? |
Server-based and client-based |
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Which types of computers on a network can work independently of the network and process and manage its own files |
Thick client |
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Which network communication medium has a single conductive wire surrounded by a grounded shield of braided wire |
Coaxial cable |
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What is the most delicate network communication medium? |
fiber optics cable |
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What provides the interface between the computer and the network medium |
Network interface card |
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What is the simplest network hardware device that can be used to connect several computers |
Network hub |
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An agreed upon set of rules that data uses to move through a network |
Network protocol |
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Thin client |
Requests services and resources from a server. |
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Similar to a hub, but sends data only to those devices to which the data are directed |
network switch |
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What are the four common topology configurations |
bus , ring, star, mesh |
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Fluoroscopy is the domain of the |
radiologist |
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Fluoroscopy is what type of exam |
dynamic, real time |
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Fluoroscopic mA range |
.5-5mA |
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During fluoro, the SOD on a fixed unit cannot be less than how many inches |
15 |
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During fluoro image intensification, the X-ray beam exits the patient and strikes the |
input screen |
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What does the output screen do |
absorbs electrons and emits light photons |
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What shape is the input screen |
concave |
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Edge distortion is also known as
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vignetting |
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Mobile flouro systems have a limited SOD of |
12 inches |
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Photocathode |
Absorbs light and emits electrons |
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Electrostatic lenses |
Accelerate and focus the electrons |
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Function of an AEC |
remove the need for the radiographer to set an exposure time |
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Most important fact to remember then using AECs |
positioning |
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What configuration are the AECs usually in |
three chamber |
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What happens if the primary beam is collimated over an AEC |
overexposure |
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What happened if your collimating is too wide |
underexposure |
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Emphysema causes |
underexposure |
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Fluid in the lungs causes |
overexposure |
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How many women are diagnosed with breast cancer annually |
209,000 |
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How many men are diagnosed with breast cancer annually |
1,900 |
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what is the ESE for a 5-cm compressed breast |
1,000 mR |
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When was the first dedicated mammography machine introduced |
1967 |
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The first dedicated screen/film system for mammography was called? -When was it introduced? |
Lo Dose I -1972 |
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Lo Dose I reduced exposure to the patient by how much |
20X |
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What was the downside to the Lo Dose I system |
loss of resolution |
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What system did Kodak introduced in 1975 |
Min-R |
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What phosphor did Min-R use |
Gadolinium oxysulfide |
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When did the exam for mammography become implemented by the ARRT |
1991 |
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First digital mammography unit was introduced in |
2000 |
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Mammography units use what type of generators |
high-frequency |
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What is good about using a high-frequency generator |
Allow better control of kVp, mAs and exposure time and reduces equipment bulk |
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kVp selections for mammography will range from |
22-40 |
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What kVp range is used in clinical practice |
25 and 28 kVp |
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What is the disadvantage of using the low kVp |
high absorption rate which contributes to patient exposure |
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Mammography machines have a mA selection from |
20-100 |
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Power ratings of mammography generators is |
3-10 kW |
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In clinical practice, typical exposure times for a standard projection would be |
0.4 to over 1 second |
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In clinical practice, typical exposure times for a magnification technique would be |
2 to 4 seconds |
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Using an AEC on a 4cm compressed breast, the exposure time can range from |
0.05 ms to over 1 second |
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What purpose do the AECs have for mammography |
They decrease repeat rate- it is impossible to tell how dense a breast is which makes it difficult to figure out a manual technique |
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Optical density of the mammographic phantom should be |
no less that 1.20 and preferably about 1.30 OD |
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For AECs, the backup timer shuts off at what mAs for grid exposures |
600 mA |
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For AECs, the backup timer shuts off at what mAs for non-grid/ magnification exposures |
300 mA |
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How should the radiographer adjust for the repeat radiograph if the backup time is reached during a breast exposure |
Increase kVp |
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What technique should be used when imaging breast implants |
manual technique |
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Grids will increase exposure to the patient by how much |
2-3X
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What ratio are mammography grids |
low - 4:1 or 5:1 |
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Grids remove what percent of scatter |
80-90% |
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What is the function of the compression device |
to decrease the thickness of the breast and increase contrast |
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Advantages of using the compression device |
- reduced mag -reduced tissue thickness -reduced exposure -reduced motion unsharpness - improved visualization - more uniform exposure |
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Resolution on mammography machines |
10 lp/mm |
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Advantages of digital mammography |
- ability to manipulate the image's contrast and density -capacity to transmit images - archiving for simplified storage and ready access |
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What are the different types of detectors with digital mammography |
-Phosphor flat panel -Phosphor CCD -Selenium flat panel -Computer radiography imaging plates |
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Why is quality control testing done |
to ensure that high image quality is always maintained |
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What is the first line of defense in preventing, recognizing, and reporting QC issues |
The tech |
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A comprehensive set of activities designed to monitor and maintain a system or piece of equipment |
Quality Control |
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What are the techs daily QC Duties |
-inspect and clean cassettes - inspect hinge and latch - erase imaging plates -verify digital interfaces and network - inspect laser printer |
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What are the techs weekly QC duties |
-Clean and inspect receptors - clean air intakes of the reader - Clean display screen - Clean computer keyboard and mouse |
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What are the techs monthly QC duties |
- reject analysis - reject reasons - positioning errors - marker errors - equipment malfunction errors -clean imaging plates - artifact identification - problem reporting |
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When should you erase the imaging plates |
If they have not been exposed for over 24 hours or if you're unsure of the last exposure |
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Physicists responsibilities include |
-Reestablish baseline values. -Check exposure indicator accuracy with calibrated ion chamber. - Determine exposure trends. -Analyze repeat rates. - Review QC records. -Analyze service history. |
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How often will the physicist come to review |
semiannually to annually |
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three types of focal spot test tools |
1. Line pair resolution tools 2. Star test patterns 3. Pinhole cameras |
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How is the collimator tested |
A lead marker is placed on each corner of the light field |
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How much can your collimator be off between your primary beam image and your light field |
+/- 2% |
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How much can your central ray be off |
1% |
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How much can your distance vary |
+/- 10% |
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How much can your centering be off |
+/- 2% |
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How much can your angle vary |
+/- 1% |
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How much can your kVp vary |
+/- 5% |
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How much can your mA be off |
+/- 10% |
