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63 Cards in this Set
- Front
- Back
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Ultrasound Imaging Component |
pulser, transducer, receiver, memory, display |
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Using the velocity mode, the higher the position on the color bar, the slower the velocity of the RBCs |
False |
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The operator has control over the receiver function demodulation? |
false |
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Which is not a primary component of the diagnostic US imaging system? |
Picture Archiving and communication system |
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For 32 shades of gray, how many bits per pixel are required? |
2^5 2x2x2x2x2=32 |
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Write the Doppler shift formula |
2 x speed of blood x T x F x cos/ prop. speed |
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Multiple focal zones are typically used to image |
testees and thyroid |
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List some functions that are considered to be preprocessing? |
TGC; Dyn Range; Res; Fill in Interpolation |
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Post processing? |
Annotation; Calipers; Inversion; Read mag |
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Which functions is related to adjustment for attenuation of sound? |
TGC |
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What imaging system component is responsible for receiving and processing the echo information? |
receiver |
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How are signals stored in a digital scan converter? |
binary numbers |
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What part of the imaging unit can handle the smallest dynamic range? |
monitor |
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How can the sonographer amplify the signal and make the overall image brighter? |
gain |
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What’s another name for old school tv monitor? |
Cathode Ray Tube CRT |
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PACS |
picture archiving and communication system |
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Resistance to motion because of two moving objects touching each other is called? |
friction |
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the tendency of an object to maintain its “status quo” is? |
inertia |
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The fluids thickness or stickiness is called? |
viscosity |
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What does M-mode record? |
time- horizontal axis motion- vertical axis |
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A higher persistence level will make your image appear how? |
smoother image |
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The operator has control over all of the following receiver functions EXCEPT for |
demodulation |
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Poiseuille’s equation is used to predict what in long straight tubes? |
volume flow rate |
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Which imaging system component is responsible for storing digital echo signal information? |
receiver |
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In variance mode the color green on the display indicates what type of flow? |
turbulent |
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The process of eliminating or suppressing small voltage amplitudes in order to reduce noise is called? |
rejection/ threshold |
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What process turns the negative signal components into positive ones? |
rectification |
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What is threshold? |
process of eliminating or suppressing small voltage amplitudes to reduce noise |
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In Dopple ultrasound, the red blood cells act mainly as what? |
reflector/ scatter of sound |
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Three receiver functions that the operator has control over? |
rejection compression amplification |
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When does aliasing occur? |
nyquist line exceeded |
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When an electron beam is directed in a fixed pattern of a horizontal sweeps across the monitor from left to right and top to bottom, what is produced? |
raster scan |
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The formula “penetration depth x number of focal zones x lines per frame is less than or equal to 77,000 relates to what resolution? |
temporal |
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How many shades of gray can be displayed using a 4-but system? |
16 shades |
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How does the sonographer fix aliasing? |
image depth |
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Can you name 4 advantages of power doppler? |
angle independence no aliasing improved sensitivity deeper penetration |
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Formula for doppler shift? |
2 c speed of blood x t x f x cos/ speed |
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What is the term used to describe the number of pulses used to interrogate a single Color line? |
packet size |
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What is the greatest source of pressure in the body? |
heart |
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M mode records ? on the horizontal axis and ? on the vertical axis? |
time ; motion |
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What is the responsibility of the receiver? |
process and receive echo info |
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Fill in Interpolation is a technique used to fill in missing what? |
pixels |
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Which image system component is responsible for storing digital echo signal information? |
digital scan converter |
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By adjusting overall ? the sonographer amplifies the signal to make the overall image brighter |
gain |
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If flow resistance is doubled, what happens to volume flow rate? |
halved |
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Processing and analysis of the frequency present in a pulses wave doppler signal is accomplished by using what mathematical process? |
FFT |
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The operator has control over all of the following receiver functions EXCEPT for |
demodulation |
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In Doppler ultrasound, the red blood cells act mainly as what? |
reflector |
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When does aliasing occur? |
when the nyquist line is exceeded |
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Positive Doppler shift |
reflector moving toward sound of source |
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High resolution monitors advantages |
better spatial res. more lines and pixels |
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What angle between the sound beam and the direction of motion will the doppler shift be at a minimum? |
90 degrees |
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When using color doppler, what happens to frame rate? |
decreases |
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on the color doppler display, the color blue indicates flow in what direction from the transducer? |
away |
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When the reflector and the source are moving toward each other, what color would be displayed? |
red |
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What’s the advantage of storing info in a digital format? |
uniformity, durability, speed, stability, accuracy |
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Turbulent blood flow |
chaotic random different noisy |
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speed vs velocity |
speed- magnitude velocity- magnitude and direction |
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Black vessel? |
color gain too low less than 90 degree angle no flow |
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What does autocorrelation determine? |
mean and variance of Doppler shift signal color flow doppler |
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Doppler shift echo are commonly detected in the signal processor using a mathematical technique called? |
FFT |
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A digital scan converter stores signals by using what? |
binary numbers |
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What makes teleradiology possible? |
picture archiving and communication system |
