Term
| What are the 5 things you should adjust first? |
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Definition
1) Image in long axis
2) Steer the color box
3) Gain
4) Scale (PRF)
5) Filter |
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Term
ACOUSTIC POWER
_____ this to improve color filling. |
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Definition
| - Increase, but remember this increases the patient exposure. |
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Term
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Definition
- Can be controlled by operator
- Increase it to improve axial resolution
- Decrease it to improve scale and penetration |
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Term
Wider boxes _____ FR.
Longer boxes ______ FR.
Deeper boxes _____ FR. |
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Definition
- Decrease
- Decrease
- Decrease |
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Term
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Definition
- Steer the box to give optimal angle with the flow.
- Steer function isn't available with SECTOR probe.
- Use heel toe instead. |
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Term
| How does FR (line density) affect color filling? |
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Definition
| - The more lines the better color filling and resolution, however the slower the FR. |
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Term
| How does Data number affect color filling? |
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Definition
| - Data number or packet size (number of pulses sent out to interrogate each line) improves color filling, especially with low velocities, however the bigger packet size, the slow the FR. |
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Term
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Definition
| Scale ADJUSTS the MINIMUM and MAXIMUM VELOCITIES displayed in COLOR. |
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Term
| What functions does the receiver do? |
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Definition
- Gain (Amplification)
- Filter (High-pass filter) |
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Term
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Definition
| - AMPLIFICATION of the RETURNED signal is needed because RBCs are POOR REFLECTORS. |
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Term
| What do you get if the gain is high? |
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Definition
| A "Noisy" image; lots of "CONFETTI" |
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Term
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Definition
- FILTER is a HIGH-PASS FILTER or WALL FILTER that only allows HIGH VELOCITIES to pass, meaning the returning echoes of slower velocities are filtered out and therefore not displayed.
- INCREASE filter to get rid of noise
- DECREASE filter to pick up the low flow velocities |
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Term
| What functions does the scan converter do? |
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Definition
- Reverse
- Map type
- Color CDI smooth
- Frame interpolate
- Balance
- M.A.P. |
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Term
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Definition
- With REVERSE (INVERT) you can DISPLAY which color signifies FLOW TOWARDS THE PROBE.
> RABT
> BART |
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Term
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Definition
| - ADJUSTS the FRACTION towards or away. |
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Term
| What are the different MAP TYPES? |
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Definition
- Velocity
- Variance
- Power |
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Term
| Explain FRAME INTERPOLATION |
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Definition
- FRAME INTERPOLATION creates INTERMEDIATE frames to show CONTINUOUS motion and AVERAGES them.
- DOES NOT affect temporal resolution. |
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Term
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Definition
- PERSISTANCE AVERAGES several FRAMES to show CONTINOUS MOTION.
- FRAME RATE is NOT AFFECTED (SAME # of frames are displayed)
- TEMPORAL RESOLUTION is AFFECTED (temporal changes may be lost due to averaging) |
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Term
| Explain CDI TIME SMOOTHING |
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Definition
- WIth CDI TIME SMOOTHING several lines are averaged.
- TEMPORAL RESOLUTION is NOT AFFECTED. |
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Term
| Explain CDI SPATIAL SMOOTHING |
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Definition
- Averages several pixels in the longitudinal or transverse direction for a SMOOTHER appearance.
- TEMPORAL RESOLUTION is NOT affected. |
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Term
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Definition
| COLOR PRIORITY (AKA THRESHOLD or BALANCE) prioritizes color or 2D image. |
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Term
| What happens if the Balance is low? |
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Definition
| - If the balance (threshold, color priority) is low, the COLOR's PRIORITY will be low, hence showing more of a black and white 2D in the vessel instead of color. |
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Term
| What happens if the balance is high? |
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Definition
| If the balance (threshold, color priority) the COLOR's PRIORITY will be high, hence showing lots of color in the vessel instead of black and white. |
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