Module 1 : Quality Assurance Flashcards
(55 cards)
1
Q
main reason for quality assurance
A
reality of patient misdiagnosis exists if the pages we think we see are not real
2
Q
quality assurance definition
A
- program that ensures proper and consistent operation of imaging system
3
Q
7 things that quality assurance ensures
A
- proper equipment operation
- detection of gradual degradation of performance
- minimizes machine down time
- minimizes repeat examination s
- sonographer and patient safety
- cost efficiency
- maintains standards
4
Q
three main people responsible for QA
A
- physician
- sonographer
- service (biomedical/manufacturer)
5
Q
the physicians role in QA
A
- the director
- assess images for overall quality
6
Q
the sonographers role in QA
A
- the front line
- may perform routine testing and record keeping
- routine maintenance (cleaning filters and visual inspections)
7
Q
routine maintenance the sonographer may do
A
- clean surface
- clean recording devices
- clean air filters
- assess cables and trasnducers
- film/image recording quality
8
Q
the two types of service personnel
A
- the manufacturer
- the biomedical personnel
9
Q
role of the manufacturer in QA
A
- provide routine preventative maintenance and repair equipment as needed
10
Q
role of biomedical personnel in QA
A
- responsible for acceptance testing when machine arrives on site to ensure patient and employee safety
11
Q
what is acceptance testing
A
- sophisticated testing when systems are place into operation
- image performance and power output are measured and the system checked to see that it will work with ancillary equipment in the department
12
Q
what is routine performance testing
A
- aout measuring image performance
- ASSESSING FOR CHANGES OVER TIME
13
Q
the key component to a good QA program is
A
- record keeping
- consistency
+ person, temp, focus, time
14
Q
AIUM 100
A
- older testing device
- plastic case contain 0.75mm steel rods arranges in groups and filled with water alcohol and algicide
- inexpensive but have no grayscale and non attenuation
15
Q
phantoms 2 types
A
- tissue equivalent phantoms
- AIUM 100
16
Q
tissue equivalent phantoms
A
- structure than contains one of more materials to simulate a body of tissue in its interaction with ultrasound
17
Q
phantoms - purpose and characteristics
A
- plastic case that contains a gel mixed with graphite poweder and rod groups plus solid and cystic lesions
- give a much better approximation of clinical performance since they allow for testing of gray scale, attenuation , speed of sound
18
Q
characteristics tissue equivalent phantoms must have to act as soft tissue
A
- attenuation coefficiente (1/2F)
- speed of sound (1540m/s)
- backscatter coefficient/ relative contrast
- elasticity
- thermal properties
19
Q
tissue equivalent phantoms can do what testing
A
- dead zone measurement
- detailed resolution
- distance accuracy
- image uniformity
- depth of penetration
- cyst imaging capabilities
20
Q
what is the dead zone
A
- the area in the near field close to the transducer also known as the MAIN BANG
21
Q
dead zone QA technique
A
- scan rod group a from side A
- the last pin that you can fully resolve closest to the probe is the dead zone depth
- record measurement and check again over time
22
Q
what is axial resolution
A
- ability to separate interfaces along the path of the beam
23
Q
axial resolution QA technique
A
- involves measuring the smallest separation visible between the axial resolution pins at various depths
- watch for changes over time
- scan rod group b from side A
- the smallest distance between the pins that we can resolve is the axial resolution
24
Q
what is lateral resolution
A
- ability to separate interfaces across the beam
- related to beam width
25
lateral resolution QA technique
- measuring the lateral resolution pins and is dependant on depth and focus
- need to have the same depth and focus every time
- side A rod group C
- look at which rod has the least amount of point spreading is and measure the beam width
- look for changes over time
26
what is elevational resolution
- aka slice thickness and Z axis
| - ability to resolve echoes in the 3D plane
27
elevational resolution QA technique
- for quantitative assessment you need a different phantom with a RAMP
- for qualitative assessment look at the cystic structures as see how well they are resolved
- side A cyst group e
- look for number of internal echoes have focus right at the cyst so you know lateral resolution is at its best
- look for changes over time
28
distance accuracy
- both horizontal and vertical distance accuracy can be measured using pins
- IMPORTANT TO MEASURE OVER LARGE DISTANCE TO DETECT SMALL MARGINS OF ERROR
29
distance accuracy QA technique
- measuring pins at a known distance with callipers and comparing numbers
- look for changes over time
30
TGC characteristics
- user specific test where results are based on the observation of the individual performing the test
- images may be captures with different slide pod configurations under different conditions and compared over time
31
image uniformity
- test a linear arrays consistency along th array
| - look for inhomogeneous regions or areas of non uniformity
32
what is sensitivity
- ability to detect weak echoes
33
sensitivity QA technique
- maximum depth of visualization
| - power and gain are optimized for penetration and the observer records the death where brightness starts to fade
34
dynamic range
- measures the number of shades of gray displayed the machine
- subjective test need good record keeping
- images compared over time
35
what is contrast resolution
- measures the ability to distinguish between simulated lesion to similar echogenicity
- controlled by dynamic range
- BIT DEPTH IS ULTIMATELY RESPONISIBLE FOR CONTRAST RESLOLUTION
36
contrast resolution QA technique
- scanning solid, cystic, hypo echoic, echogenic lesions
| - see how well you can differentiate lesions from other surrounding tissue
37
contrast vs contrast resolution
- can have lots of contrast but still have poor CONTRAST RESOLUTION
38
registration
- test for older static b scanner to ensure arm positioning is accurate for the reconstruction of an image
39
registration QA technique
- involves scanning pins from 3 sides to see if the lines intersect at one point
40
two types of doppler phantoms
- flow = like TE phantom
| - string or belt = like AIUM 100 test object
41
flow doppler phantoms
- like TE phantoms
- close match to clinical experience
- expensive
42
flow phantoms can measure what factors
- maximum depth (sensitivity for color)
- gate position accuracy
- volume flow and velocity accuracy
- color flow penetration
- image congruency test
43
string or belt doppler phantoms
- move a string or belt in a water bath
- do not match the clinical experience
- cheap
44
3 other applications for phantoms
- demonstration
- training
- research
45
7 other specialty phantoms
- biopsy
- mass
- 3D
- cryosurgery
- brachytherapy
- HIFU (high intensity frequency ultrasound)
- IVUS (intravenous ultrasound)
46
what are output testing devices
- used by service personnel or manufacturers to evaluate the systems power output
47
3 types of output testing devices
- hydrophone
- power (force) balancers
- calorimeter
48
hydrophone also had 4 other parts
- plotter (articulated arm)
- spectrum analyzer
- oscilloscope
- schlieren system (acoustic optical method)
49
what is a hydrophone
- small (1mm) transducer that produces a voltage proportional to the received acoustic pressure (piezoelectric element)
- used with a plotter to be moved throughout the sound field and produce a beam profiler
50
hydrophone capabilities with an oscilloscope
- SPL
- PD
- PRP
- PRF
- DF
51
hydrophone capabilities with a spectrum analyzer
- resonant frequency
- bandwidth
- fractional bandwidth
- Q factor
52
what is force balance used to measure
- power
53
what is a force balance
- sophisticated sensitive micro balance that is phased in the sound field and calibrated to determine acoustic power and intensity
54
what is a calorimeter
- essentially a heat meter used to measure acoustic power
| - an enclosed fluid container with a very sensitive thermocouple detects temp change and can determine acoustic power
55
future QA developments
- as tech changes need new products
- phantoms designed to have increased durability and longevity but have to keep up with advancements to technology
+ thin film phantom
+ smaller resolution point targets
- some machines have ability to self evaluate which would help with subjectivity of manual evaluation
