Test 7 (Chapter 13 & 14)

True or false. Compensation processes all reflected signals in a similar manner.

False.

True or false. If 100 scan lines make up an image and the frame rate is 30 per second, then the transducer's frequency is 3,000 Hz.

False.

True or false. If the imaging depth of a scan is 15 cm and there are 100 lines in the image, then the number of pulses making up the scan is 1500.

False.

True or false. The critical factor in determining frame rate, line density, and imaging depth is the transducer style.

False.

True or false. The number of lines per frame and the frame rate determine the frequency.

False.

True or false? An ultrasound system with a longer pulse duration will generally have better temporal resolution.

False.

True or false? The length of a pulse does not directly influence the temporal resolution.

False.

Which of the following choices is best when the image on your ultrasound system displays reflectors only in a region far from the transducer but no reflectors in a region close to the transducer? A. adjust the system's compensation B. use a higher frequency transducer C. decrease the output power D. adjust the reject level

A.

Which of the following choices is best when the image on your ultrasound system displays only reflectors in a region close to the transducer but no reflectors that are deep? A. adjust the system's compensation B. use a higher frequency transducer C. increase the output power D. adjust the reject level

A. adjust the system's compensation

Which of the following is most important in determining the frame rate of a system? A. depth of view B. dynamic range of the receiver C. transducer frequency D. transmitter output

A. depth of view

A sonographer reduces the sector angle from 90 degrees to 30 degrees. At the same time, the ultrasound system automatically increases the line density from 1 line per degree to 2 lines per degree. No other changes are made. What will happen to the frame rate? A. increases B. decreases C. remains unchanged

A. increases

A sonographer adjusts an ultrasound machine to change the sector size from 90 to 45 degrees. Nothing else changes. What happens to the frame rate? A. it is doubled B. it remains unchanged C. it is halved D. it is tripled

A. it is doubled

A sonographer adjusts an ultrasound scan to double the depth of view from 5 cm to 10 cm. What happens to the frame rate? A. it is halved B. it doubles C. it increases from 5 to 10 hz D. it is unchanged

A. it is halved

This type of pulser generates numerous electrical spikes, which ultimately create a single sound pulse: A. pulsed wave, phased array B. continuous wave C. pulsed wave, single crystal

A. pulsed wave, phased array

Which of the following is most important in determining the frame rate of a system? A. speed of sound in the medium B. dynamic range of the receiver C. transducer frequency D. transmitter output

A. speed of sound in the medium

All of the following are components of an ultrasound system except: A. transducer B. alternator C. display D. pulser E. synchronizer F. receiver

B. alternator

This type of pulser generates a constant electrical signal in the form of a sine wave: A. pulsed wave, array B. continuous wave C. pulsed wave, single crystal

B. continuous wave

What is the fundamental limitation of temporal resolution? A. imaging depth B. speed of sound in the medium C. line density D. sector size

B. speed of sound in the medium

A sonographer increases the line density from line per degree of sector to 3 lines per degree of sector. What is the most likely consequence of this action? A. frame rate increases B. temporal resolution decreases C. imaging quality decreases D. temporal resolution increases

B. temporal resolution decreases

What is the time needed to make a single image if the frame rate of an ultrasound system is 20 Hz? A. 1 s B. 0.02 s C. 0.05 s D. 15 Hz

C. 0.05 s

Under certain conditions, an ultrasound system creates each image in 0.01 seconds. What is the frame rate? A. 1 Hz B. 10 sec C. 100 Hz D. 200 Hz E. 0.02 Hz

C. 100 Hz

What is the frame rate if each image of the ultrasound system is created in 0.02 sec (1/50 sec)? A. 20 Hz B. 100 Hz C. 50 Hz D. 15 Hz

C. 50 Hz

Place these functions in the order in which of the ultrasound system performs them: A. reject B. demodulation C. amplification D. compression E. compensation

C. amplification E. compensation D. compression B. demodulation A. reject (HINT: it is in alphabetical order)

Which of the following choices is best when the image on your ultrasound system is saturated (too bright everywhere)? A. decrease the amplification or gain B. use a higher frequency transducer C. decrease the output power D. adjust the reject level

C. decrease the output power

Which of the following will improve a system's temporal resolution? A. increased sector angle B. increased line density C. increased PRF D. increased frequency

C. increased PRF

A sonographer adjusts an ultrasound system to change the sector size from 90 to 45 degrees. The frame rate was unchanged. What else must have happened? A. temporal resolution B. sector size was doubled C. line density was doubled D. imaging depth was halved

C. line density was doubled

This type of pulser generates a single electrical spike, which ultimately creates a single sound pulse: A. pulsed wave, phased array B. continuous wave C. pulsed wave, single crystal

C. pulsed wave, single crystal

A sonographer reduces the sector angle from 90 degrees to 30 degrees. At the same time, the ultrasound system automatically increases the line density from 1 line per degree to 3 lines per degree. No other changes are made. What will happen to temporal resolution? A. increases B. decreases C. remains unchanged

C. remains unchanged

Which of the following forms of resolution improve when frame rate increases? A. lateral B. longitudinal C. temporal D. spatial resolution

C. temporal

The acoustic power of a sound beam emitted from a transducer is determined by the __________ of the pulser's signal. A. pulse repetition frequency B. frequency C. voltage D. rectification

C. voltage

When the frame rate is 30 Hz, how long does it take to create a frame? A. 30 sec B. 3 sec C. 0.3 sec D. 1/30 sec E. 1/3 sec

D. 1/3 sec

Which of the following is consistent with improved temporal resolution? A. color Doppler B. more gray shades C. more detail D. higher frame rate

D. Higher frame rate

All of the following are functions of the receiver except: A. demodulation B. suppression C. amplification D. attenuation

D. attenuation

A sonographer adjusts an ultrasound scan to double the depth of view from 5 cm to 10 cm. If the frame rate remains the same, which one of the following also occurs? A. increased line density B. wider section C. multi-focus D. narrower section

D. narrower section

All of the following decrease temporal resolution except: A. lower frame rate B. deeper imaging C. multi-focus D. narrower sector

D. narrower sector

A sonographer, using a phased array ultrasound system, turns off the multi-focus feature. What is the most likely consequence of this action? A. frame rate decreases B. temporal resolution degrades C. imaging depth increases D. temporal resolution improves

D. temporal resolution improves

True or false. Amplification processes all reflected signals in a similar manner.

True.

True or false. If 100 scan lines make up an image and the frame rate is 30 per second, then the system's pulse repetition frequency is 3,000 Hz.

True.

True or false. If the imaging depth of a scan is 15 cm and there are 100 lines in the image, then the number of pulses making up the scan is 100.

True.

True or false. The number of lines per frame and the frame rate determine the pulse repetition frequency.

True.