PROBLEM SOLVING

What is the wavelength of 2 MHZ sound in soft tissue?

0.77 mm

The amplitude of an acoustic wave decreases from 27 pascals to 9 pascals. If the initial power in the wave was 27 watts, what is the wave’s final power?

3 watts

The intensity of a signal declines from 1.5 mW/cm² to 0.75 mW/cm². How many decibels is this change in intensity?

-3 db

A sound beam travels 9 cm in soft tissue. The attenuation coefficient is 3 db/cm. What is the total attenuation that the sound beam experienced?

27 db

A sound beam with an intensity of 45 W/cm² strikes a boundary and 70% of the wave’s intensity is reflected. How much is transmitted?

30%

An ultrasound pulse has a pulse repetition period of 1.2 msec, a spatial pulse length of 0.2 mm, and a wavelength of 0.4 mm. What5 is the axial resolution of the system?

1.0 mm

Two ultrasound system produce acoustic pulses. A pulse from System 1 has a wavelength of 0.5 mm, 4 cycles per pulse, and a pulse repetition period of 1.8 msec. Which ultrasound system will have a lower numerical value of axial resolution?

Both are the same

The diameter of a disc shaped, unfocused piezoelectric crystal is 1.2 cm. The NZL length is 8 cm. What is the best estimate for the lateral resolution at a depth of 16 cm.

1.2 cm

An ultrasound system with a 4.0 MHz transducer is used to image structures as deep as 15 cm. Twenty images are produced each second, each requiring 100 acoustic pulses. What is the PRF of the system

2,000 Hz

Which of the following sector imaging systems will have the best image detail if all other parameters are identical?

A 70 degree with 84 pulses/image