Week 7 Range Equation

Question 1

The elapsed time from pulse creation to pulse reception is

Answer 1

go-return time or time of flight

Question 2

How is time of flight and how deep a pulse travels related?

Answer 2

Directly

Question 3

Greater distances…….

Answer 3

Prolong the time of flight

Question 4

depth of a reflector formula

Answer 4

mm= 1.54mm/us x go-return time (us)/2

Question 5

13 Microsecond rule

Answer 5

for every 13 Microseconds of go-return time, the object creating the reflection is 1 cm deeper in the body.

Question 6

Total distance traveled

Answer 6

is twice the reflector depth

Question 7

13 us time of flight is equal to…..

Answer 7

Reflector depth = 1 cm
Total distance traveled = 2 cm

Question 8

26us time of flight is equal to

Answer 8

reflector depth = 2 cm
Total distance traveled = 4 cm

Question 9

When a sonographer adjust a systems maximum imaging depth…..

Answer 9

PRP is altered

Question 10

PRP is

Answer 10

Go return time of a sound pulse between the transducer and the bottom of the image.

Question 11

Depth of view is shallow

Answer 11

PRP is short

Question 12

Depth of view is deep

Answer 12

PRP is long

Question 13

How are PRP and depth of view related?

Answer 13

Directly Related

Question 14

PRP formula

Answer 14

PRP (us)= imaging depth (cm) x 13 us/cm

Question 15

When depth of view is 10 cm, what is PRP ?

Answer 15

130 microseconds

Question 16

How are PRF and maximum imaging depth related?

Answer 16

Inversely

Question 17

PRF formula

Answer 17

PRF (Hz)= 77,000cm/s / imaging depth (cm)

Question 18

When depth of view is shallow

Answer 18

PRF is High

Question 19

When depth of view is deep

Answer 19

PRF is low

Question 20

When depth of view is set to 7.7 cm PRF is what?

Answer 20

10,000 Hz
77,000/7.7

Question 21

When depth of view is set to 15.4 PRF is what

Answer 21

5,000 HZ
77,000/15.4

Question 22

A sound wave is created by a transducer, reflects off an object and returns to the transducer. The go-return time is 26 us. What is the depth of the reflector

Answer 22

2 cm

2cm x 13us =26us

Question 23

The maximum imaging depth during an ultrasound exam is 10 cm. The sonographer adjusts the imaging depth to 20 cm, what happens to the PRP?

Answer 23

it doubles