Secound Physics Test

1. The effects of ultrasound upon tissue are called

Angle of incident

Absorption

Bioeffects

2. A sound beam travels a total of 10 cm in 2 seconds. What is the speed of the sound in this medium?

10/cmsec

2 cm/sec

5 cm/sec

0.2 cm/sec

3. The higer the emitted frequency the more likely a pulsed wave signal is to alias.

True

False

4. Only pulsed wave Doppler exams have a sample volume

True

False

5. A sound beam is traveling from east to west. Blood is traveling from north to south. Which statement is true?

No Doppler shift will be created

A maximum Doppler shift is created

A minimum Doppler shift is created

The Doppler shift is in the MHz range

6. The power in a beam is 1 watt and the area is 5cm^2. What is the beam's intensity?

5 W/cm^2

1 W/cm^2

0.2 W/cm^2

1 W/cm^2

7. What is the difference between speed and velocity?

Speed has velocity

Velocity has magnitude

Speed has direction and magnitude

Velocity has magnitude and direction

8. What is the current method of processing Doppler signals?

Autocorreclation

Zero crossing detection

Range gating

FFT Fast Fourier Transfrom

9. The shallower the sample volume is the more likely a signal is to alias

True

False

10. What is the fram rate if each image of ultrasound system is created in 0.02 seconds (1/50th sec)?

20 Hz

100 Hz

50 Hz

15 Hz

11. The Doppler effect is present as a ______ when the source and the receiver are _-

Frequency shift, in motion relative to each other

Velocity shift, in motion relative to each other

Frequency shift, in motion not relative to each other

12. All of the these decrease temporal resolution except:

Lower frame rate

Deeper imaging

Multi focus imaging

Narrower sector

13. Which of the following will increase frame rate by a factor of three?

Setting imaging depth to 3 cm

Changing imaging depth from 10 cm to 3 cm

Changing sector angle from 90 to 45 degrees

Changing imaging depth from 21 to 7 cm

Increasing output power by 3 db

14. Starting from the same point, the receiver is moving towards the west at 12 miles/hour and the source is moving towards the west at 10 miles/hour. The Doppler shift is

Positive

Negative

15. Doppler shift produces information about

Location

Red blodd cells motion

Velocity

16. What is the typical range of Doppler shift found in diagnostic imaging examinations?

1 - 20 Hz

20 Hz and 20 kHz

1 - 10,000 Khz

17. You are using a tissue equivalent phantom. At a particular depth, reflections are no longer observed. What are you evaluating?

Dynamic range

Spatial resolution

Axial resolution

Sensitivity

18. The accuracy of placing reflections on an A-mode B-mode or M-mode in relation to the depth of the reflectors is called

Dynamic range

Spatial positivity

Axial resloution

Depth calibration

19. Which of the following will have no effect upon temporal resolution?

Increasing imaging depth

Increasing transducer frequency

Increasing # of foci

Decreasing imaging depth

Decreasing sector size

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

True

False

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

Explanation

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

21. Starting from the same point, the sound source is moving towards the west at 12 miles/hour and the receiver is moving towards the west at 10 miles/hour. The Doppler shift is

Positive

Negative

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

True

False

The critical factor in determing frame rate, line density and imaging depth is time.

Explanation

The critical factor in determing frame rate, line density and imaging depth is time.

23. Using a tissue equivalent phantom, two pins at depths of 2 cm and 10 cm are imaged. On the system display, you measure the distance between two reflections created by these pins. What are you evaluating?

Dynamic range

Range calibration

Spatial postivity

Lateral resolution

24. If the intensity remains the same while the power is doubled, what happens to the beam area?

Quadrupled

Doubled

Halved

Unchanged

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

The frame rate increases

The temporal resolution decreases

The imaging quality decreases

The temporal resolution increases

26. Two pins in a test object are 100 mm apart. The ultrasound system displays these pins as being 90 mm apart. How far apart will the system display a pair of pins that are actually 70 mm apart?

90 mm

70 mm

63 mm

60 mm

7 mm

The 10 mm error stated in the question represents 10% underestimation of distance. 70/0.10 = 7 70-7= 63

Explanation

The 10 mm error stated in the question represents 10% underestimation of distance. 70/0.10 = 7 70-7= 63

27. Which of the following is most important in determining the frame rate of a system?

Speed of sound in the medium

Dynamich range of the reciever

Frequency of the transducer

Transmitter output

28. A sonographer adjusts an ultrasound machine 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 changed?

Increased line density

Wider sector

Multi focus imaging turned on

Narrower sector

29. An 8 MHz transducer with a PRF of 5,000 Hz is imaging to a depth of 7 cm. What is the Nyquist frequency?

4 MHz

3.5 MHz

2.2 kHz

2.5 d b

The actual Nyquist limit is 1/2 of the PRF, in this example 2.5kHz or 2,500 Hz. In this ex. the perfect answer does not appear in the choice. In cases such as this, select the answer that is closest to the actual answer

Explanation

The actual Nyquist limit is 1/2 of the PRF, in this example 2.5kHz or 2,500 Hz. In this ex. the perfect answer does not appear in the choice. In cases such as this, select the answer that is closest to the actual answer

30. Which of the following waves will have the shortest wavelengths?

Low frequency traveling in a fast medium

Low frequency traveling in a slow medium

High frequency traveling in a fast medium

High frequency traveling in a slow medium

31. A sonographer changes an image's sector size from 90 to 45 degrees. The frame rate remained unchanged. What else must have happened?

The temporal resolution was doubled

The sector size was doubled

The line density was doubled

The imaging depth was halved

32. A sonographer using a phased array ultrasound system turns off the multi-focus feature. What is the most likely consequence of this action?

The temporal resolution was doubled

The sector size was doubled

The line density was doubled

The imaging depth was halved

Secound Physics Test

1. The effects of ultrasound upon tissue are called

2.

What first name or nickname would you like us to use?

2. A sound beam travels a total of 10 cm in 2 seconds. What is the speed of the sound in this medium?

3. The higer the emitted frequency the more likely a pulsed wave signal is to alias.

4. Only pulsed wave Doppler exams have a sample volume

5. A sound beam is traveling from east to west. Blood is traveling from north to south. Which statement is true?

6. The power in a beam is 1 watt and the area is 5cm^2. What is the beam's intensity?

7. What is the difference between speed and velocity?

8. What is the current method of processing Doppler signals?

9. The shallower the sample volume is the more likely a signal is to alias

10. What is the fram rate if each image of ultrasound system is created in 0.02 seconds (1/50th sec)?

11. The Doppler effect is present as a __________ when the source and the receiver are _____-

12. All of the these decrease temporal resolution except:

13. Which of the following will increase frame rate by a factor of three?

14. Starting from the same point, the receiver is moving towards the west at 12 miles/hour and the source is moving towards the west at 10 miles/hour. The Doppler shift is

15. Doppler shift produces information about

16. What is the typical range of Doppler shift found in diagnostic imaging examinations?

17. You are using a tissue equivalent phantom. At a particular depth, reflections are no longer observed. What are you evaluating?

18. The accuracy of placing reflections on an A-mode B-mode or M-mode in relation to the depth of the reflectors is called

19. Which of the following will have no effect upon temporal resolution?

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

21. Starting from the same point, the sound source is moving towards the west at 12 miles/hour and the receiver is moving towards the west at 10 miles/hour. The Doppler shift is

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

23. Using a tissue equivalent phantom, two pins at depths of 2 cm and 10 cm are imaged. On the system display, you measure the distance between two reflections created by these pins. What are you evaluating?

24. If the intensity remains the same while the power is doubled, what happens to the beam area?

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

26. Two pins in a test object are 100 mm apart. The ultrasound system displays these pins as being 90 mm apart. How far apart will the system display a pair of pins that are actually 70 mm apart?

27. Which of the following is most important in determining the frame rate of a system?

28. A sonographer adjusts an ultrasound machine 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 changed?

29. An 8 MHz transducer with a PRF of 5,000 Hz is imaging to a depth of 7 cm. What is the Nyquist frequency?

30. Which of the following waves will have the shortest wavelengths?

31. A sonographer changes an image's sector size from 90 to 45 degrees. The frame rate remained unchanged. What else must have happened?

32. A sonographer using a phased array ultrasound system turns off the multi-focus feature. What is the most likely consequence of this action?

11. The Doppler effect is present as a ______ when the source and the receiver are _-