SPI_통합영어 1.

Front

Sound attenuation can be observed by: Reflection, Scattering, Conversion of sound to heat, Compression

Back

Compression

Answer explanation

Attenuation results from reflection, scattering, and absorption. Compression is a phase of the wave, not a loss mechanism.

Front

Increasing transmit power during a pelvic ultrasound examination affects what?

Back

All of the above (Penetration, Acoustic power, Image brightness)

Answer explanation

Increasing transmit power boosts penetration, image brightness, and the acoustic energy sent into the body.

Front

You have decreased the acoustic power by -3 dB. What happens to the intensity?

Back

The intensity has been halved.

Answer explanation

A -3 dB adjustment represents a 50% reduction in intensity in decibel scale.

Front

You are scanning a large mass that is composed primarily of fat. What are you most likely to encounter?

Back

Axial misregistration of objects distal to the mass on the screen due to the slower propagation speed through fat

Answer explanation

Fat has a slower propagation speed than other soft tissues, which can lead to axial misregistration in ultrasound images.

Front

What does a TI reading of 1 indicate during a sonographic examination?

Back

The output level is high enough that temperature could increase as much as 1° C if the transducer were held stationary.

Answer explanation

A TI of 1 suggests that the acoustic output could potentially cause a 1°C rise in tissue temperature under certain conditions, such as prolonged stationary scanning.

Front

In a sonographic examination, if the thermal index (TI) is greater than 1, where would the increase in temperature be greatest? Options: Liver, Lung, Kidney, Bone

Back

Bone

Answer explanation

Bone absorbs ultrasound energy more efficiently than soft tissues, leading to greater temperature increases, especially near bone-tissue interfaces.

Front

Snell's law describes:

Back

The angle of sound transmission at an interface between media having different propagation speeds

Answer explanation

Snell’s law relates the angle of incidence and transmission based on the propagation speed differences between two media.

Front

Which transducer would provide the least amount of signal attenuation in a sonographic exam on a large patient? Options: 2.5 MHz, 3.5 MHz, 5.0 MHz, 10 MHz

Back

2.5 MHz

Answer explanation

Lower-frequency transducers attenuate less and are more effective for deep penetration in large patients.

Front

Imaging a structure that is highly attenuating. Which imaging effect is expected? Options: Enhancement, Increased penetration, Shadowing, Refraction

Back

Shadowing

Answer explanation

Highly attenuating structures absorb and reflect more sound, leading to posterior acoustic shadowing.

Front

What occurs at the boundary of two media with the same acoustic impedance?

Back

All of the sound will be transmitted.

Answer explanation

When acoustic impedance is identical between two media, no reflection occurs and all the sound is transmitted across the boundary.