Physics QA

Question 1

Who directs the QA program?

Answer 1

Physician

Question 2

Who assesses quality of images?

Answer 2

Radiologist

Question 3

Who are the 2 types of service personnel?

Answer 3

Manufacturer and biomedical personnel

Question 4

What does the manufacturer do?

Answer 4

Preventative maintenance and repair equipment

Question 5

What does the biomedical personnel do?

Answer 5

Acceptance testing when machine arrives on site to ensure safety.

Question 6

What is acceptance testing?

Answer 6

Sophisticated testing before machines are operated.

Question 7

What can a phantom assess?

Answer 7

Resolution, sensitivity, accuracy, etc

Question 8

What is the key component to a good QA program?

Answer 8

Record keeping

Question 9

How many times are is the accuracy checked in a year?

Answer 9

2-3 times under warrranty.

Question 10

What is the AIUM 100?

Answer 10

Older testing device, encased in plastic case that contains 0.75mm steel rods arranged in groups and filled with water, 9% alcohol and algaecide

Question 11

Why are AIUM 100’s not used?

Answer 11

No greyscale and do not attenuate.

Question 12

What are the films made of on the tissue phantoms?

Answer 12

Saran or polyurethane

Question 13

What are the containers made of?

Answer 13

ABS, PVC or acrylic

Question 14

How is a “good” phantom characterized?

Answer 14

Attenuation coefficient, speed of sound, back scatter coefficient, elasticity, thermal properties

Question 15

What can phantoms test?

Answer 15

Dead zone, detailed res, distance accuracy, image uniformity, depth of pen, cyst imaging capabilities

Question 16

Describe the dead zone

Answer 16

Area in near field close to transducer (AKA: main bang)

Question 17

What is an acceptable dead zone measurement?

Answer 17

15mm

Question 18

When can the dead zone be very larger?

Answer 18

Old mechanical probes

Question 19

Ability to separate interfaces along the path of the beam?

Answer 19

Testing axial resolution

Question 20

Ability to separate interfaces across the beam?

Answer 20

Testing lateral resolution - measuring pins

Question 21

What is lateral res dependant on?

Answer 21

Depth and focus

Question 22

What test requires a different type of phantom?

Answer 22

Elevation resolution/slice thickness

Question 23

What kind of phantom is used for elevational testing?

Answer 23

Spherical void phantom or beam profile phantom

Question 24

Is elevational resolution qualitative or quantitative?

Answer 24

Quantitative

Question 25

How can we detect margins of error?

Answer 25

Measure over larger distances to detect small errors

Question 26

What does it mean when we see a dark vertical band?

Answer 26

Usually a broken crystal

Question 27

What does sensitivity test?

Answer 27

Ability to detect weak echoes | - increase depth until it darkens

Question 28

What is dynamic range?

Answer 28

Number of shades of grey (contrast)

Question 29

How can we determine capability of dynamic range?

Answer 29

Compare images over time/ compare to previous records

Question 30

Contrast resolution

Answer 30

Ability to distinguish between simulated lesions of similar echogenicity

Question 31

What does contrast res detect?

Answer 31

Difference in appearances of solid, cystic, echogenic, hypoechoic lesions

Question 32

When is registration tested?

Answer 32

Tested on older static B scanners to ensure arm positioning is accurate to reconstruct an image

Question 33

What does registration look like?

Answer 33

Scanning pins from 3 different sides to see if lines intersect at one point

Question 34

What are the different types of Doppler phantoms?

Answer 34

Flow & String/belt

Question 35

What is a flow Doppler phantom?

Answer 35

Match clinical experience - expensive

Question 36

What are string phantoms?

Answer 36

Move string or belt in water belt and are affordable

Question 37

What do flow phantoms measure?

Answer 37

``` Max depth Gate position accuracy Volume flow & velocity accuracy Colour flow penetration Image congruency test ```

Question 38

What else can phantoms be used for?

Answer 38

Demonstration, training, research & development

Question 39

Hydrophone

Answer 39

Measure aspects of our beam technical parameters | Produces a voltage proportional to received acoustic pressure wave

Question 40

Output testing devices

Answer 40

Hydrophone, power balances, calorimeter

Question 41

What can a hydrophone measure with an oscilloscope?

Answer 41

``` SPL PD PRP PRF DF ```

Question 42

What can a hydrophone measure with a spectrum analyzer?

Answer 42

Resonant (f), bandwidth, Q factor

Question 43

What does a force balance measure?

Answer 43

Acoustic power

Question 44

Calorimeter

Answer 44

“Heat meter” used to measure acoustic power (thermocouple) | - amount of heat produced determines power that is being produced

Question 45

What is being tested when scanning in axial resolution?

Answer 45

Reverberation

Question 46

What is added to a hydrophone to measure fractional bandwidth?

Answer 46

Spectrum analyzer

Question 47

What is considered a “good” tissue equivalent phantom?

Answer 47

One half the frequency times the path length

Question 48

Who is responsible for semi-annual maintenance?

Answer 48

Manufacturer

Question 49

What uses a sound absorbing block and sophisticated scale to measure acoustic power and intensity?

Answer 49

Force balance

Question 50

What test is performed with a Doppler phantom ensure that colour flow is displayed accurately on the screen?

Answer 50

Image congruency

Question 51

What is the AIUM 100 test object used to assess?

Answer 51

Dead zone

Question 52

What is the systems best axial resolution based on?

Answer 52

Greatest separation between pins (2mm)

Question 53

Who is the leader to carry out QA performance testing?

Answer 53

Radiologist & sonographer

Question 54

Role of manufacturer

Answer 54

Routine preventative maintenance and repair

Question 55

Role of biomedical personnel

Answer 55

Acceptance testing

Question 56

How are pins configured in phantoms?

Answer 56

“J” configuration - compensates for reverb artifact

Question 57

What group of pins is used to assess the lateral resolution?

Answer 57

Vertical group - will show beam width related to point spreading at various depths