Ch 22: Quality Assurance

Question 1

This is the routine periodic evaluation of an u/s system to guarantee optimal image quality.

Answer 1

quality assurance (QA)

Question 2

QA evals must be performed how often?

Answer 2

periodically and routinely

Question 3

Four requirements for a QA program are:

1. __ of system components
2. repairs
3. __ maintenance
4. __ keeping

Answer 3

assessment, preventive, record

Question 4

Five goals of a QA program are:

1. guarantee proper system __
2. detect gradual __
3. minimize __
4. reduce the # of __ exams
5. reduce the # of __ scans

Answer 4

operation, changes, downtime, non-diagnostic, repeat

Question 5

Three kinds of QA phantoms:

Answer 5

1. tissue equivalent
2. Doppler
3. beam profile/slice thickness

Question 6

Proper methods for a QA program are:

1. test under __ conditions
2. use __ instrument settings
3. use a phantom with __
4. image in an __

Answer 6

defined, constant, measurable characteristics, identical environment

Question 7

T/F? Subjective information is factual and repeatable.

Answer 7

FALSE, objective

Question 8

T/F? A subjective statement is influenced by a person’s experience and beliefs.

Answer 8

true

Question 9

QA programs should be base on (objective/subjective) standards.

Answer 9

objective

Question 10

This kind of phantom is used to evaluate gray scale and tissue texture.

Answer 10

tissue equivalent

Question 11

In what ways is a tissue equivalent phantom similar to soft tissue?

Answer 11

1. speed of sound
2. attenuation
3. scattering characteristics
4. echogenicity

Question 12

This kind of phantom is used to evaluate Doppler systems.

Answer 12

Doppler phantom

Question 13

This kind of phantom includes a circulation pump which propels fluid through ‘vessels’.

Answer 13

Doppler phantom

Question 14

T/F? Doppler phantoms can assess pulsed and continuous wave Doppler, but not color and power mode.

Answer 14

FALSE, all Doppler modalities

Question 15

This kind of phantom evaluates slice thickness and elevational resolution.

Answer 15

slice thickness phantom

Question 16

This kind of phantom contains a diffuse scattering plane that is at an angle to the incident sound beam.

Answer 16

slice thickness phantom

Question 17

T/F? Soft tissue phantom can be used to measure slice thickness.

Answer 17

FALSE, only slice thickness phantoms

Question 18

This refers to the ability of a system to display low-level echoes.

Answer 18

sensitivity

Question 19

Two forms of sensitivity are…

Answer 19

normal and maximum.

Question 20

At this sensitivity setting, all the pins, solid masses, and cystic structures in the test phantom are accurately displayed.

Answer 20

normal

Question 21

All subsequent QA and performance measurements are made at __ sensitivity.

Answer 21

normal

Question 22

T/F? Normal sensitivity setting should not vary from one test to the next.

Answer 22

true

Question 23

At this sensitivity setting, the output power and amplification of the system are at maximum practical levels.

Answer 23

maximum

Question 24

At which sensitivity level is the depth of the display measured?

Answer 24

maximum

Question 25

This is the region close to the transducer where images are inaccurate.

Answer 25

the dead zone

Question 26

The dead zone results from the time it takes the system to...

Answer 26

switch from transmit to receive mode.

Question 27

__ frequency transducers have a thinner dead zone than __ frequency transducers.

Answer 27

Higher, lower

Question 28

This can be positioned between the transducer and the patient to allow accurate imaging of superficial structures.

Answer 28

acoustic standoff or gel pad

Question 29

This is the ability of the system to place reflections in proper position while imaging from different orientations.

Answer 29

registration accuracy

Question 30

This describes the system's accuracy in placing reflectors at correct depths located parallel to the sound beam.

Answer 30

range accuracy or vertical depth calibration

Question 31

An increasingly deeper dead zone may indicate a...

Answer 31

cracked crystal, detached backing material, or a longer pulse duration.

Question 32

Errors in range accuracy may be caused by...

Answer 32

system malfunction or the phantom sound speed not being 1540 m/s.

Question 33

This is the system's ability to place echoes in their correct position when the reflectors are perpendicular to the sound beam

Answer 33

horizontal calibration

Question 34

Digital calipers should be checked in __ directions.

Answer 34

both vertical and horizontal

Question 35

The accuracy of reflector depth positioning in A-, M-, B-mode and 2-D imaging is called...

Answer 35

depth calibration.

Question 36

Axial resolution tests use pins that are __ to the sound beam.

Answer 36

parallel

Question 37

Lateral resolution tests use pins that are __ to the sound beam.

Answer 37

perpendicular

Question 38

This kind of phantom is used to evaluate the dimension, texture, and fill-in of cysts.

Answer 38

tissue equivalent