QA/stats

Question 1

4 test devices/phantoms used as part of a QA program to assist sono to validate the accuracy and consistency of the US systems

Answer 1

1. test object
2. tissue equivalent phantom
3. doppler phantom
4. slice thickness phantom

Question 2

Hydrophone is used to evaluate (4)

Answer 2

Pulse amplitude
PD
PRP
Period

Question 3

What does the hydrophone do

Answer 3

Measures acoustic output / pressure

Question 4

What do the tissue phantoms and test object measure? (3)

Answer 4

Penetration
Registration
Resolution

Question 5

What QA method used refraction properties of water to evaluate beam pattern and measure intensity

Answer 5

Schlieren method

Question 6

A calorimeter is used to measure the

Answer 6

Power of the beam

Converts sound energy into heat - measures tiny changes in temperature

Question 7

Dead zone

Answer 7

Distance closest to the transducer in which imaging cannot be performed

Question 8

Hydrophone specifically evaluates which parameters (3)

Answer 8

Acoustic output - relationship btwn amt of acoustic pressure and the voltage produced. Measures period, PRP, PD

Question 9

Sensitivity - define and formula

Answer 9

Ability to detect PRESENCE of disease

TP/TP+FN

Question 10

Specifity - define and formula

Answer 10

Ability to detect ABSENCE of disease

TN/TN+FP

Question 11

Negative predictive value - define and formula

Answer 11

How often test is correct when its negative for the disease

TN/TN+FN

Question 12

Accuracy - define and formula

Answer 12

% of exams that agree with gold standard

TP + TN/ TP+TN+FP+FN

Question 13

Elastography depicts tissue ….

Answer 13

Stiffness

Question 14

Positive predictive value - define and formula

Answer 14

How often test is correct when positive for disease

TP/TP+FP

Question 15

Quality assurance

• Routine evaluation of (2)
• What does it provide assessment of? What does it ensure?
• What testing device will QA program usually use?

Answer 15

Routine evaluation of the transducers AND ultrasound system

Provides assessment of image quality, ensures consistency

Testing via tissue equivalent phantom

Question 16

Beam profiler measures

Answer 16

Transducer characteristics

Question 17

AIUM 100 test object cannot evaluate (3)

Answer 17

Penetration
Grey scale
Compression

Question 18

What does the AIUM 100 test object evaluate?

Answer 18

System sensitivity

Question 19

Transducer characteristics evaluated by

Answer 19

Beam profiler

Question 20

Force-balance system measures

Answer 20

Power of the sound beam

Question 21

Acoustic output testing considers only the (2)

Answer 21

Pulser/beam former

and transducer

Question 22

Which testing device can simulate pulsatile or retrograde flow?

Answer 22

Moving string phantom

Question 23

*TO evaluates

Answer 23

System sensitivity

Question 24

*Beam profiler is a testing device that measures:

Answer 24

Transducer characteristics

Question 25

*The ability to place reflections in proper positions regardless of the imaging orientation describes

Answer 25

Registration accuracy

Question 26

*Testing device a QA program will likely use

Answer 26

Tissue equivalent phantom

Question 27

*what evaluates operation of the US system?

Answer 27

Tissue equivalent phantom

Question 28

What can the TEP measure that the test object cannot? (3)

Answer 28

Compression, penetration, contrast resolution