Term
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Definition
| Perfuses the face and scalp |
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Term
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Definition
| Perfuses the brain and eyes |
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Term
| What branch off the carotid artery is medial? |
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Definition
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Term
| What branch off the carotid artery is lateral? |
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Definition
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Term
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Definition
| Supplies both the ICA and ECA |
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Term
| What is the function of a duplex study? |
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Definition
| Ultrasound image for anatomy and doppler for physiology |
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Term
| What are the characteristics of ICA flow? |
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Definition
| low-resistance with lots of diastolic flow. "Whoosh" sound |
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Term
| What are the characteristics of ECA flow? |
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Definition
| Somewhat higher-resistance than ICA with less diastolic flow. Sharp sound. |
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Term
| What are the characteristics of CCA flow? |
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Definition
| Elements of both ICA and ECA since it supplies both. |
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Term
| What is the Doppler principal? |
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Definition
| Frequency is shifted by motion. |
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Term
| What is the Doppler equation and what are the influences on freqency shift? |
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Definition
Δf = 2f0V(cosθ)/c
Δf=frequency shift
is enfluenced by:
f0=emitted frequency
V=velocity
cosθ=angle
c=velocity of waves in the medium (tissue) |
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Term
| Considering the Doppler Principle, does a positive shift in frequency suggest higher velocity than a negative shift? |
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Definition
| Yes, because frequency shift has a direct relationship with velocity. |
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Term
| What is spectral analysis? |
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Definition
Assign a pixel to each separate shifted frequency. Pixel is brighter or darker depending on the strength of the echo at that frequency.
The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. |
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Term
| What are the 3 elements (kinds of information) on the spectral display? |
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Definition
1. Time as demonstrated on the X axis
2. Frequency shift (velocity) as demonstrated on the Y axis
3. Echo strength for a given frequency shift as demonstrated with pixel brightness. |
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Term
| What does a bright pixel signify? |
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Definition
| Lots of blood moving at a set velocity. |
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Term
| What does a dark pixel signify? |
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Definition
| Not much blood moving at a set velocity. |
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Term
| What Doppler angles are ok and why? |
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Definition
| 50-60°, For trade consistency |
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Term
| How do you produce good Doppler angles? |
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Definition
| Rock the beam or steer the angle. |
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Term
| How do you tell whether flow is toward the beam or away? |
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Definition
| Visualize a perpendicular line to the beam direction. If the flow direction is above that perpendiclar line, flow is more toward the beam than away. If flow direction is below the perpendicular line, then flow is more away than toward. Steer the beam to the right so flow is toward the beam. Steer the beam to the left so flow is away from the beam. |
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Term
| What should you ask yourself before freezing a waveform for measurement? |
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Definition
| 1. Are the waveforms clear? 2. Are the walls clear? 3. Is the angle-correct cursor lined up with the walls? |
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Term
| What do you always do after freezing an image but before measuring? |
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Definition
| Double-check the angle correction. The ends of the cursor should be parallel to the walls. |
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Term
| What do you measure on a Doppler waveform? |
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Definition
| Peak systolic volume and end diastolic volume |
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Term
| What Peak Systolic Volume (PSV) suggests hemodynamically significant stenosis of the ICA? |
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Definition
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Term
| What End Diastolic Volume (EDV) suggests really severe (>80%) stenosis? |
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Definition
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Term
| What End Diastolic Volume (EDV) suggests >70% stenosis? |
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Definition
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Term
| What governs diastolic flow character? |
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Definition
Diastolic flow character is governed by distal resistance.
"If it's a low-resistance vascular bed (e.g., the brain, or any organ), then there will be lots of forward flow during diastole. If high-resistance (e.g., the lower extremities), then there will be reversal of flow during diastole. An intermediate-resistance bed (e.g., the face/scalp perfused by the ECA, or the upper extremity) will be sharper but still may have a bit of diastolic flow." ~Ridgway~ |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Anterior Wall a.k.a. Free Wall |
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Term
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Definition
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Term
| On an Apical Doppler, where should you place the gate (sample volume) for stenosis? |
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Definition
| For evaluating stenosis, get the gate at the tips of the open leaflets. (AV valves for diastole and SL valves for systole) |
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Term
| On an Apical Doppler, where should you place the gate (sample volume) for regurgitation? |
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Definition
| For evaluating regurgitation, get the gate behind the leaflets and check for flow when valve is closed. (AV valves for systole and SL valves for diastole) |
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Term
| What is normal velocity values for the aortic valve? |
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Definition
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Term
| What is normal velocity values for the mitral valve? |
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Definition
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Term
| What is normal velocity values for the pulmonic valve? |
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Definition
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Term
| What is normal velocity values for the tricuspid valve? |
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Definition
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Term
| Where within the heart are velocities lower and why? |
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Definition
| Right heart; pressure gradient is not as high |
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Term
| How do you orient yourself while doing a carotid scan and Doppler? |
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Definition
| Feet are always to the right of the screen |
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Term
| How do you orient yourself while doing an apical 4-chamber and 5-chamber cardiac scan and Doppler? |
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Definition
| The right heart is on the left and the left heart is on the right with the apex at the top and the base at the bottom. |
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Term
| Where do you set the baseline while doing a Doppler on AV valves? |
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Definition
| Since blood flow is toward the beam, the Doppler waves will be above the baseline; therefore, set the baseline low on the scale. |
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Term
| Where do you set the baseline while doing a Doppler on SL valves? |
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Definition
| Since blood flow is away from the beam, the Doppler waves will be below the baseline; therefore, set the baseline high on the scale. |
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Term
| What are the characteristics of AV valve Doppler images? |
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Definition
| AV valve have a M-shape characteristic somewhat like M-mode due to primary passive filling and secondary active filling with the atrial kick. |
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Term
| What are the characteristics of SL valve Doppler images? |
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Definition
| SL valves have a single-phase waveform. |
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Term
| What do you measure for cardiac Doppler? |
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Definition
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Term
| If velocities are higher than WNL, what does that signify? |
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Definition
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Term
| How is the pressure gradient across a valve calculated? |
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Definition
Bernoulli's equation
V1A1=V2A2 |
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