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CVT Doppler
CVT Doppler
32
Medical
Professional
09/19/2012

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Term
Nyquist limit
Definition
Velocity at which aliasing occurs
Term
Aliasing
Definition
Velocities that exceed the measuring capacity of a pulsed-Doppler system
Term
Continuous wave
Definition
Elements are constantly transmitting and receiving sound
Term
Pulsed wave
Definition
Single element which acts as both a transmitter and receiver
Term
Modal velocity
Definition
Velocity at which the majority of blood cells are moving
Term
Color Doppler
Definition
Utilization of color and pulsed wave technology to obtain information
Term
For imaging echocardiography, the best image is obtained when the transducer is ____________ to the structures being imaged.
Definition
perpendicular
Term
Qualification
Definition
detects that an abnormality is present. It does not accurately determine the severity of the abnormality.
Term
Quantification
Definition
detects that the abnormality is present & accurately determines the severity.
Term
Doppler flow towards transducer will be where in regards to the baseline?
Definition
above the baseline
Term
Doppler flow away from the transducer will be where in regards to the baseline?
Definition
below the baseline
Term
The velocities portrayed with Doppler represent the “___________,” which is the velocity at which the majority of blood cells are moving.
Definition
modal velocity
Term
The area being measured is selected by moving the “__________” to the area of the heart you want to measure.
Definition
sampling gate
Term
Velocity at which aliasing occurs is called
Definition
Nyquist limit and calculated as:
Nyquist Limit = PRF/2
(Pulse Repetition Frequency)
Term
Aliasing is represented on spectral Doppler by what?
Definition
The flow pattern wrapping around the paper
Term
With color doppler how is aliasing represented?
Definition
Color flow reversal
Term
Peak Velocity Range for TV
Definition
0.3-0.7 m/s
Term
Peak Velocity Range for MV
Definition
0.6-1.4 m/s
Term
Peak Velocity Range for PV
Definition
0.6-0.9 m/s
Term
Peak Velocity Range for AV
Definition
1.0-1.7 m/s
Term
Peak Velocity Range for LVOT
Definition
0.7-1.1 m/s
Term
Used to measure pressure gradients across valves in heart
Definition
Bernoulli equation
Term
Bernoulli equation (formula)
Definition
P = 4 x (V2^2 – V1^2)
–V2 is the velocity on the distal side of the valve in relation to flow
–V1 is the velocity on the proximal side of the valve in relation to flow
–P = Pressure
–If the flow on the proximal side of the valve is 1 m/sec or less you take it out of the equation.
Term
Simplified Bernoulli (formula)
Definition
P=4(V2^2 )
Term
To calculate RVSP the patient must have what?
Definition
some degree of tricuspid regurgitation
Term
Right atrial pressure is estimated based on?
Definition
–Normal values are 5-10 mmhg=normal(not diliated and collapsing >50%
–10-15mmhg=normal size but not collapsing >50%
–15-20mmhg=Dilated and not collapsing at all
Term
ASD (Atrial Septal Defect) (Q)
Definition
–Qp site
•RVOT
–Qs site
•Mitral annulus or LVOT
Term
VSD (Ventricular Septal Defect) (Q)
Definition
–Qp site
•RVOT or mitral annulus
–Qs site
•LVOT
Term
PDA (Patent Ductus Arteriosus)
Definition
–Qp site
•Mitral annulus or LVOT
-Qs site =Tricuspid annulus or RVOT
Term
This is also called stroke volume through a valve
Definition
TVI
Term
Continuity Equation (Formula)
Definition
•Time velocity integral (TVI) Also called VTI(velocity time integral)
•Flow = CSA x Velocity
•Flow = CSA x TVI
•FlowLVOT = FlowAV
•CSALVOT x VelocityLVOT = CSAAV x VelocityAV
•CSALVOT x TVILVOT = CSAAV x TVIAV This is the stroke volume through that valve.
Term
Shunt Equation (Formula)
Definition
–Qp/Qs is used for determining the presence of a shunt and the direction
–Qp/Qs = (SV Qp site) ÷ (SV Qs site) where:
Qp = flow rate at the shunt location
Qs = flow rate at the shunt location
SV = Stroke volume (stroke volume is CSA X TVI)
–The location for determining the stroke volume depends upon the location of the shunt
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