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Flashcards in Chapter 22 Deck (24):
1

What is quality assurance?

the routine, periodic evaluation of an ultrasound system to guarantee optimal image quality

2

When should quality assurance be performed?

routinely and periodically

3

What are the four requirements for a quality assurance program?

1. assessment of system components
2. repairs
3. preventive maintenance
4. record keeping

4

What are the five goals of quality assurance program?

1. guarantee proper operation of the system
2. detect gradual changes
3. minimize downtime
4. reduce the number of non-diagnostic exams
5. reduce the number of repeat scans

5

What are devices that enable the sonographer to perform quality assurance?

1. tissue equivalent phantom
2. Doppler phantom
3. beam profile/slick thickness phantom

6

What are the proper methods for quality assurance?

1. test under know, defined conditions
2. use constant instrument settings
3. use a phantom with measurable characteristics
4. image in an identical environment

7

What are objective info?

factual, repeatable, and able to be counted
Used for quality assurance programs

8

In what ways are tissue equivalent phantom similar to soft tissue?

speed of soft tissue
attenuation
scattering
echogenicity

9

What is evaluated with tissue equivalent phanotom?

gray scale and tissue texture, also multi-focus and adjustable focus phased arrays

10

What do Doppler phantoms include?

vibrating string
moving belt
flow phantom

11

true or false: Doppler phantoms assess pulse, CW, color and power mode?

true

12

What does slice thickness determine?

elevational resolution

13

When is sensitivity assessed?

when the sonographer adjusts the system controls to change echo brightness from barely visible to full brightness

14

What are normal sensitivity setting?

are those at which all the pins, solid masses, and cystic structures in the test phantom are accurately displayed

15

Where is the dead zone?

is the region close to the transducer where images are inaccurate

16

Which transducer have a thinner dead zone?

higher freq transducers

17

What is vertical depth calibration?

describes the systems accuracy in placing reflectors at correct depths located parallel to the sound beam

18

What are horizontal calibrations?

the systems ability to place echoes in their correct position when the reflectors are perpendicular to the sound beam

19

What is depth calibration?

the accuracy of reflector depth positioning in A mode, M mode, and B-mode and 2D imaging

20

What is axial resolution in quality assurance?

the smallest distance at which two pins positioned parallel to the sound beam are displayed as two distinct echoes
scanning sets of successively closer spaced pins within the phantom

21

What is lateral resolution in phantoms?

min distance at which two side by side pins are displayed as two distinct images

22

What is another way to evaluate lateral resolution?

is to measure the width of reflections on the display that are created by point targets in the phantom

23

What is uniformity?

the systems ability to display similar reflectors in the phantom with echoes of equal brightness.

24

What are mock cysts and solid masses?

tissue equivalent phantom used to evaluate the dimension, texture and fillin of cycts