Ultrasound Physics Ch 7: Range Equation

What is the go-return time(GRT) or time-of-flight(TOF)?

time from pulse creation to pulse reception (how long there and back)

The time-of-flight is ____ related to how deep a sound pulse travels.

directly

What is the Average speed of sound in soft tissue?

1.54 mm/us

1,540 m/s

154,000 cm/s

What equation can be used to calculate the depth of a reflector using the go-return time?

Depth(mm) = 1.54mm/us x go-return time(us) > divided by 2

For every 13 ,us of go-return time, the object creating the reflection is ______ deeper in soft tissue.

1 cm

The total distance that a pulse travels is

twice the reflector depth

The pulse repetition period is the go-return time of a sound pulse....

Between the transducer and the bottom of the image

When the depth of view is shallow, PRP is ______.

short

When the depth of view is deep, the PRP is _____.

long

What is the equation for PRP, imaging depth, and the 13 microsecond rule

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

PRP is _______ related to the maximum imaging depth.

directly (the listening time is what is shorter or longer, transmit time remains the same)

Ex. When the depth of view is set to 10 cm,

PRP is 130 us (10 x 13 us).

Ex. When the depth of view is set to 5 cm,

PRP is 65 us (5 x 13 us).

When depth of view is shallow, PRF is ________.

high

When depth of view is deep, PRF is ________.

low

What equation is used to find PRF in soft tissue?

PRF(Hz) = 77,00cm/s divided by imaging depth (cm)

PRF is _____ related to the maximum imaging depth.

inversely.

Ex. The greater the depth, the lower the PRF.

Ex. When the depth of view is set to 7.7 cm, PRF is 10,000 Hz (77,000/7.7 = 10,000).

Ex. When the depth of view is set to 15.4 cm, PRF is 5,000 Hz

(77,000 / 15.4 = 5,000).