BASIC PTE EXAM REVIEW Flashcards
Time Gain Compensation is used on the echo to?
Increase the system gain of the reflected 2d signaals based on their time required to be reflected.
What does the compression knob do?
Improve the gray scale visualization of the 2D image
Which of the following parameters cannot be changed with changing the image depth?
A. Pulse Repitition Frequency
B. Duty Factor
C. Pulse Repitition Period
D. Listening Time
E. Propagation Speed
Propagation Speed
What is the pulse repetition frequency?
The number of pulses per second
What is the duty factor?
The duty factor is the fraction of time that an ultrasound pulse is actually being produced.
AKA Percentage of time the machine is sending out pulses
If the ultrasound is produced as a continuous wave (CW), the duty factor will have a value of 1. Intensity and power are proportional to the duty factor.
What is a pulse repetition period?
Pulse repetition period (PRP):
Time from the beginning of one pulse to the beginning of the next.
Usually expressed in microseconds (µs). PRP decreases as PRF increases. More pulses occur in a second, less time from one to the next.
How does increasing the depth change the PRF (pulse repetition frequency)?
Decreased (Fewer pulses can go out)
How does decreasing the depth change the PRF (pulse repetition frequency)?
Increases PRF; More pulses can go out
How does depth affect listening time?
Deeper the structure = Longer the listening time
How does the duty factor change with imaging depth?
Inversely related
Increased depth = Decrease in Duty Factor
Decreased Depth = Increase in Duty Factor
How does depth affect PRF?
Decreased Depth = Increased PRF
Increased Depth = Decreased PRF
How does PRP change with Depth?
Increased Depth = Increased Pulse Repetition Period
Decreased Depth = Decreased Pulse Repetition Period
If you decrease the spatial pulse length will lead to Improvement in what resolution?
What is equation for spatial pulse length?
Axial Resolution (Ability to distinguish objects front to back)
AXIAL RESOLUTION = 1/2 (SPL)
What is lateral resolution determined by?
Beam Width
more narrow = more you can distinguish two objects close together
What is elevational resolution determined by?
Beam height
The shorter the beam, the better the resolution
Can the pulse duration be adjusted?
No
What is the cosine of 30?
0.87
What is the middle scallop is indicated in the ME Mid-Commissural views for Mitral valve?
A2 scallop = in the Middle
P1 on right, A2 (middle), P3 on left of the screen
Where would you look for the most repairable mitral valve scallop lesion?
ME LAX = P2 scallop
What scallops of the mitral valve are seen in the ME LAX view?
A2 (other unlabeled) and P2 (green arrow)
What omniplane is the RV inflow view obtained?
Insert the probe to the stomach, sector depth 12cm, angle 0°
From mid TG SAX (0°) turn probe right to put RV in center
Rotate omniplane angle to 90° - 120 degrees
Anteflex until RV is horizontal
How do you estimate LVEDP on echo?
Duration of Pulmonary Venous Arterial Wave Reversal (AREV - Duration)
AR REV = Pulmonary Venous atrial reversal vs. Transmitral A wave
If a patient has Deceleration time of 467 ms, Lateral E’ velocity of 5.0 cm/sec and Vp of 30 cm/sec
What is the diastolic function?
Impaired Relaxation
How do you use deceleration time to calculate the Mitral Valve area?
The time from the Vmax to the where the velocity is equal to zero is the deceleration time. Typically, the curve will have to be extrapolated to the zero velocity.
The mitral valve area = 759 / Deceleration time
