Quality Control Flashcards
Quality Assurance (QA) & Quality Control (QC) are the two areas of activity designed to
ensure the best possible diagnosis at an acceptable radiation dose and with minimum cost.
Quality assurance deals with
people
Quality control deals with
instrumentation and equipment
_______ ) promotes the “Ten-Step Monitoring and Evaluation Process.”
The Joint Commission on Accreditation of Healthcare Organizations (JCAHO)
What is SMDA?
Safe Medical Devices Act. Mandates that any serious injury or death due to medical device be reported.
What is MQSA?
Mammography Quality Standards Act. Requires mammography facilities to be approved by the FDA
SMDA & MQSA both:
have the greatest impact on the practice of radiologic and imaging sciences.
The Hospital Corporation of America’s FOCUS-PDCA is:
The premier quality measurement consulting book
PDCA is an acronym for
Plan, Do, Check and Act. The PDCA cycle is a way of continuously checking progress in each step of the FOCUS process.
A typical QA program monitors
proper patient scheduling, reception and preparation. For example,
Appropriate exam for pt
Pt properly instructed
QA monitors
image interpretation. for example,
Pt’s disease agree with radiologist’s diagnosis
A typical QA program monitors
Appropriate exam for pt
Pt properly instructed
image interpretation
Outcome analysis
Outcome Analysis
Pt’s disease agree with radiologist’s diagnosis
Outcome Analysis
Pt’s disease agree with radiologist’s diagnosis
QC makes sure that
the equipment is in proper condition to make sure that the radiologist is provided with the best image possible
Other reasons for doing QC besides pt care:
Our litigious society demands QC records
Some insurance companies will only reimburse if there is a QC program
JCAHO will not approve of facility that does not have a QC program
Most states require a QC program
These QA activities should all be monitored by the imaging team, however:
They are principally the responsibility of the radiologist
An acceptable QC program has three steps:
Acceptance testing, routine performance monitoring, error maintenance.
When is acceptance testing performed?
before newly installed or majorly repaired equipment can be accepted by dept.
When is acceptance testing performed?
before newly installed or majorly repaired equipment can be accepted by dept.
Acceptance Testing is to be done by:
someone other than the manufacturer’s rep, such as:
Radiation physicist
Service personnel employed by hospital
Routine maintenance is performed to ensure that
the equipment is performing as expected
Routine maintenance testing helps to:
catch problems before they become radiographically apparent
Routine maintenance May be performed by:
designated tech, radiation physicist or service personnel employed by vendor
Preventive maintenance (PM) usually alleviates
unnecessary repair
QC is principally the responsibility of
the medical physicist
Error maintenance:
when errors occur in equipment performance, corrective action must occur.
Error maintenance corrections will generally be done by:
service personnel employed by the vendor
___________ and _________ have developed guidelines for QC programs in radiography as well as other imaging modalities
American College of Medical Physics and the American Association of Physicists in Medicine
Most important patient protection device of radiographic unit is
filtration of the X-ray beam.
State requires radiographic units have minimum total filtration of
2.5 mm Al
State requires radiographic units have minimum total filtration of
2.5 mm Al
Filtration Measurement is done through
the half-value layer (HVL)
Filtration is tested how often?
Annually, or any time following change in x-ray tube or tube housing
X-ray field must coincide with
light field of variable aperture light localizing collimator
Collimation Misalignment must not exceed
± 2% of the source-to-image receptor distance (SID)
With PBL collimator the x-ray beam must not be larger than
IR except in override mode
Distance tested must be within _____ and centering indicators within _____.
2% of SID, 1% of the SID
Three tools used to measure focal-spot size:
Pinhole camera
Star pattern
Slit camera
Which tool to measure focal-spot size is most popular?
Slit camera.
What tool can be used to measure spatial frequency?
Line-pair test tool
How is kVp calibrated?
Most physicists used devices based on filtered ion chambers or filtered photodiodes
When is kVp calibrated?
kVp calibration evaluated annually or whenever high voltage generator components are changed
How much variation in kVp is needed to affect image optical density & contrast?
4%
kVp should be within ___ of desired kVp
+10%
How is exposure timer accuracy measured?
Exposure time measured based on irradiation time of ion chamber or photodiode assembly
How often should exposure timer accuracy be tested?
Timer should be checked annually or whenever part of high voltage generator or operating console has undergone major repairs
Exposure timer accuracy should be within ___ of the indicated time for exposure times greater than 10 ms
+5%
Accuracy of ___ is acceptable for exposure times of 10 ms or less
+20%
Accuracy of ___ is acceptable for exposure times of 10 ms or less
+20%
AEC is evaluated by
exposing IR through various thicknesses or Al or acrylic
If the phototimer fails, the backup timer should terminate the exposure at
6s or 600 mAs, whichever occurs first
Spinning Top Test may be used to measure
the exposure timer on single phase generators.
Motorized synchronous spinning top may be used for
testing the exposure timer on three-phase units.
Electronic Timers should be able to go as low as
1 ms
The ability of a radiographic unit to produce a constant radiation output for various combinations of mA and exposure time is called
exposure linearity
The linearity is determined by a precision
radiation dosimeter
Exposure linearity must be within ____ for mA stations
±10%
If, when using any combination of kVp, mA and exposure time, the RT decides to change one factor and then return to the previous value of radiation exposure, the previous value should be precisely the same
This is known as
exposure reproducibility
Two methods used to evaluate exposure reproducibility:
Both utilize a radiation dosimeter.
Mathematical formulas can be used to determine reproducibility in both cases
Output radiation intensity should not vary by more than
±5%
Intensifying Screens Require periodic attention to minimize appearance of artifacts. How often?
Screens should be cleaned with soft, lint-free cloth and cleaning solution Not less than every other month
Aprons, gloves and gonadal shields should be radiographed or fluoroscoped _____ for defects
annually
Viewbox illumination should be photometrically analyzed
annually
Intensity of Viewbox illumination should be at least
1500 cd/m2 and Should not vary by more than ±10% over surface of illuminator
Viewbox intensity Should not vary by more than ____ over surface of illuminator
±10%
Fluoroscopy Exposure Rate – federal law and most states require that ESE (entrance skin exposure) shall not exceed
10R/min (100 mGy/min)
For interventional procedures fluoro may be equipped with a high level control
This allows an ESE up to
20 R/min (200 mGy/min)
_______________ are required to determine the adequacy of any automatic brightness stabilization (ABS) system
Lucite, Al, copper and lead filters
An ESE of approximately ____ mR may be assumed for a cassette spot film
200
An ESE of approximately ___ mR may be assumed for a photofluorospot
100
Use of a grid during photofluorospot does what to the ESE?
approximately doubles
Use of a grid during photofluorospot does what to the ESE?
approximately doubles
All fluoro systems contain either automatic brightness control or automatic exposure control. They function in manner similar to phototimer of radiographic imager.
These systems tend to deteriorate or fail with use & therefore:
should be evaluated annually
The indicated section that is to be tomogrammed and the measured level should be within
±5mm
Increments from one tomo section to the next should be accurate within
±2mm
TQM stands for:
Total Quality management
CQI stands for:
Continuous Quality Improvement
SMPTE stands for:
Society of Motion Pictures & Television Engineers
ACR suggests monitor luminescence testing be performed at least monthly by using:
SMPTE test pattern
used to evaluate monitor display reflection and assess ambient light conditions
Illuminance Meter
Near-Range luminescence meters are used:
in close proximity to monitor
Telescopic Luminance Meters: used to test from a distance of 1m
used to test from a distance of 1m
DICOMM:
Digital Imaging and Communication.
Standard that enables imaging systems from different manufacturers to communicate
DICOMM:
Digital Imaging and Communication.
Standard that enables imaging systems from different manufacturers to communicate
GSDF
Gray Scale Display Function.
Allows medical images to be transferred according to DICOM standards. Compatible with any DICOM display device.
Consistent grayscale appearance.
DIN 2001
addressed requirements for digital display systems
VESA
Video Electronics Standard Association
Provides set of instructions to help evaluate system performance
AAPM TG 18
American Association of Physicists in Medicine Task Group Report 18.
Set of test patterns to ensure acceptable clinical performance
