13 & 14 Ultrasound Physics

A sonographer increases the line density from 1 line per degree of sector to 3 lines.  What is the consequence

Which of the following is associated with uniform brightness of an image?

increasing the number of scan lines in one frame improves which of the following?

Electronic noise is reduced in the ultrasound system by this method:

Which of the following will require the TGCs to be adjusted in the most shallow portion of the display?

The lines per frame and the frame rate determine the pulse repetition frequency?

The ratio of the largest to the smallest signal that a system can handle is termed:

an adjustment is made that increased the patient exposure to ultrasound energy.  Which control below was adjusted?

With regard to ALARA, what is the best way to image deeper?

All of the following decrease temporal resolution except

You have expanded the image sector width to improve visuals What can you do to maintain the same temporal resolution

You wish to improve contrast resolution to enhance the visibility of the lesion.  you can do this by doing what?

The fundamental limitation of temporal resolution is acoustic velocity.

the sonographer turns off the multi-focus feature.  What is a consequence of this action

Which of the following is associated with uniform amplification of all signals?

What is the rationale for the ALARA principle?

What control should you adjust to account for the attenuation of sound as it propagates through tissue?

Referring to the image above, which adjustment is needed?

in real time scanning, the required PRF depend on the number of --- per frame and ---

Each completion scan of the sound beam produces an image on the display that is called a __________.

Refer to the image above.  Which adjustment is best when the image does not display any difference in tissue density?

what receiver function listed below is NOT adjustable?

Which receiver function converts the negative portion of the signal to positive?

if the image's near field was difficult to see, what adjustment is needed?

which of the following resolutions improves when the frame rate increases?

what two systems affect frame rate?

What system control should you adjust to account for sound attenuation with depth?

  The critical factor in determining frame rate, line density, and imaging depth is the type of transducer used.

As frame rate increases, the image quality may degrade.

The lines per frame and the frame rate determine the sound wave's frequency?

Which operator control affects frame rate?

What part of the ultrasound instrument is responsible for apodization, beam steering, focusing, and aperture control?

Which of the following adjustments would NOT decrease frame rate?

a sonographer changes the image sector size from 90 degrees to 45 degrees frame rate remains unchanged What else changed

Preamplification processes extremely weak signals that are susceptible to noise and often takes place in the transducer.

if the image's far field is difficult to see, what adjustment is needed?

what system control determines the amount of amplification that occurs in the reciever?

Increasing the number of foci reduces 

An entire ultrasound image is too dark.  What is the first adjustment that should be made to make the image brighter?

which of the following would decrease temporal resolution?

  What receiver function decreases the difference between the smallest and largest received signal amplitudes?

what is the frame rate if the ultrasound system creates an image in 0.02 seconds (1/50th sec)?

What is the most common way to improve signal-to-noise ratio?

which operator control adjusts the intensity of the transmitted pulse

Which adjustment is needed to improve this image

what adjustment will better display the reflectors located in the region closest to the trasnducer?

Which operator control adjusts the dynamic range of the displayed echoes?

What is the time needed to make a single image if the frame rate of the ultrasound system is 20 Hz?

A sonographer doubles the depth of view from 10 cm to 20 cm.  If frame rate is the same, which one also changes?

you wish to increase the frame rate to evaluate the fetal heart.  What should you do

Temporal resolution is only determined by ________.