Doppler Flashcards
Maximum flow is when the Doppler beam is?
A) parallel to flow
B) perpendicular to flow
C) oblique to flow
D)unattainable
A) parallel to flow
What is range resolution?
The ability to distinguish between two objects
Which Doppler has range resolution, pulse wave or continuous wave?
PW
Which Doppler has a limit on the maximum velocity pulse wave or continuous wave?
PW
What is the Doppler equation?
V= c / /cos sine x f2
Which valve lesion has the highest Doppler peak?
A) TR
B) MR
C) AI
D) PI
B) MR
What’s a typical gradient for AS?
A) 1.0-1.6 m/sec
B) 2.0-3.0 m/sec
C) 3.0-5.0 m/sec
D) 1.6-2.0 msec
C) 3.0-5.0 m/sec
Laminar flow is ?
A) irregular
B) smooth
C) shaggy
D) jagged
C) smooth
With laminar flow, where is the area of highest velocity?
The center
Smooth flow in the same direction is called?
Laminar or parabolic
What kind of flow is bullet shaped?
Laminar/ parabolic
What flow is “bullet shaped?”
Laminar/parabolic
What flow creates vortices?
Turbulent flow
Turbulent flow has blood cells that move in ____ directions with ___ velocities
Different ; varying
What are 4 factors that affect blood flow?
Pressure
Length of vessel
Diameter of vessel
Blood viscosity
The longer the vessel the greater the?
Resistance
(because the longer the vessel the more it resistance it needs to push blood through it)
The smaller diameter of the vessel the greater the?
Resistance
(the smaller the space the more resistance required to pass through)
High viscosity means high ___ and low___
Resistance ; velocity
The lower the viscosity the lower the ____ and higher ___
Resistance ; velocity
What is ghosting in color Doppler?
Flashes of color caused by moving from atomic structures and not blood flow
What would you do to prevent ghosting?
A) increase gain
B) roll the patient
C) increase water filter
D) decrease sector size
C) increase wall filter because the flashes are low velocity
