Interaction of Sound & Media

Sound waves ________, or attenuate, as they travel in the body.

• weaken

• strengthen

• multiply

• vibrate

The sound that comes back to the transducer is converted to what type of signal?

• Mechanical signal

• Electrical signal

• Light signal

• Magnetic signal

A sound wave must be converted into an electrical signal as it enters the ultrasound system to be made into meaningful information on our image.

• True

• False

This electrical signal is sent to the ultrasound system where it is ________ or amplified.

• strengthened

• weakened

• measured

• delayed

In diagnostic ultrasound, we are often interested in the degree of attenuation or the extent of amplification. What do these terms refer to?

• The loss or gain of sound wave intensity as it travels through tissue

• The speed of sound in different tissues

• The frequency of the ultrasound waves

• The resolution of the ultrasound image

How much did our sound wave weaken?

• By 10 dB

• By 20 dB

• By 30 dB

• By 40 dB

As we scan our patients, our sound waves go through all sorts of different types of media. Which of the following is NOT a type of media mentioned?

• Skin

• Muscle

• Bone

• Blood

At the boundary between these different media, a portion of the sound wave continues traveling deeper into the patient’s body. A weak portion is reflected back to the transducer. What happens to the rest of the sound wave?

• It continues traveling deeper into the patient’s body.

• It is completely absorbed at the boundary.

• It is converted into electrical energy.

• It is scattered in all directions.

Our sound wave weakens more and more as it travels through the patient’s body. This process is called ________.

• attenuation

• reflection

• amplification

• refraction

Our ultrasound system has to be so sensitive to be able to pick up these weak reflections and turn them into something meaningful.

• True

• False