PREPRY

Question 1

PRP and PRF relationship

Answer 1

Inverse

Question 2

Pulse duration is

Answer 2

The number of cycles x the period (whenever you have an equation with a multiplication sign, whatever is on the opposite side is directly related)

Question 3

Doppler shift = (equation)

Answer 3

2 x velocity x transducer frequency x cosine (angle of incidence) ALL DIVIDED BY propagation speed

(With division, numerator is directly related, denominator is inverse)

Question 4

Units Mega is 10 to the what power

Answer 4

6

Question 5

Unit Micro is 10 to the what power

Answer 5

-6

Question 6

Unit Centi is 10 to the what power

Answer 6

-2

Question 7

Unit Milli is 10 to the what power

Answer 7

-3

Question 8

Unit Kilo is 10 to the what power

Answer 8

3

Question 9

Sound cannot travel in a

Answer 9

Vacuum

Question 10

All sound waves are these two things

Answer 10

Mechanical, longitudinal

Question 11

The unit for pressure is _______ and it is

Answer 11

Pascals (Pa) and pressure is the concentration of force in an area

Question 12

What are the 7 acoustic parameters to describe a sound wave

Answer 12

1. Period
2. Frequency
3. Amplitude
4. Power
5. Intensity
6. Wavelength
7. Propagation speed

Question 13

Amplitude is units of

Answer 13

Pressuer

Question 14

Frequency is units per

Answer 14

Second

Question 15

Sonographer can only adjust these three things

Answer 15

Amplitude, power, intensity - by changing the gain

Question 16

Infrasound range

Answer 16

<20 Hz

Question 17

Audible range

Answer 17

20 Hz - 20 KHz

Question 18

Ultrasound range

Answer 18

> 20 kHz

Question 19

Propagation speed is only determined by the

Answer 19

Medium

Question 20

What determines the medium’s ability to affect propagation speed?

Answer 20

Density
Stiffness

Question 21

Stiffness aka

Answer 21

Bulk modulus

Question 22

Stiffness and what are DIRECTLY related

Answer 22

Propagation speed

Question 23

If stiffness goes up, the propagation speed will

Answer 23

Also go up (directly related)

Question 24

If density goes up, the propagation speed will

Answer 24

Go down (inverse relationship)

Question 25

Propagation speed of different mediums from low to high

Answer 25

Air, Lung, Adipose, Water, Liver, Blood, Muscle, Tendon, Bone

Question 26

Propagation speed in soft tissue

Answer 26

1540 m/s or 1.54 mm/microsecond

Question 27

Compressibility aka

Answer 27

Elasticity (low stiffness)

Question 28

Power is

Answer 28

The strength of the US beam (output power aka gain is adjustable by sonographer)

Question 29

Intensity is

Answer 29

The strength of the US beam - it is the CONCENTRATION of energy

Question 30

What are the 5 pulsed sound parameters

Answer 30

PRP PRF PD SPL DF

Question 31

Pulse duration unit

Answer 31

Microseconds

Question 32

Pulse Repetition Period what unit

Answer 32

Milliseconds

Question 33

Pulse duration is the

Answer 33

Transmission time of pulse

Question 34

Pulse Repetition Frequency (think “frequently”)

Answer 34

*how “frequently” can you send out the next pulse

Question 35

Describe the relationship of PRF and PRP in relation to a shallow and deeper depth

Answer 35

At greater imaging depths, it takes more time (PRP) for a pulse of sound to travel and how frequently (PRF) a pulse can be transmitted decreases… Greater depths = longer PRP, lower PRF (More time required pulses sent out less frequently) Shallower depths = shorter PRP, higher PRF (Less time is required, pulses can be sent out more frequently

Question 36

Duty Factor of CW is

Answer 36

100% or 1

Question 37

Duty Factor formula is

Answer 37

PD divided by PRP