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Mammography Regulations
and Quality Assurance
Presented on November 28, 2007
Karen Farris, BS RT(R)(M)
What is Quality Assurance?
� Quality Assurance is a comprehensive
concept that includes all aspects of a facility
operations
� QA includes:
� Continuing Education
� Quality Control
� Preventative Maintenance
� Calibration of Equipment
� Management Policies
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The QA program should:
� Include all of the policies and procedures for
the facility
� Be kept in a single binder
� This includes the mission statement (goals
and direction of the facility)
The QA program should:
� Include the responsibilities of each team
member
� Radiologist
� Medical Physicist
� Mammographer
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The QA program should:
� List the tests performed by the Quality
Control Technologist
� A primary QC tech should be selected;
� It is beneficial to have a back up QC tech trained
� Include test procedures
� Include forms to be used
The QA program should:
� Describe the orientation program
� Overall content
� Who receives orientation
� Who presents orientation
� When is orientation received
� How orientation is documented
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Orientation Program
� Proper use of the mammography equipment
� The facility’s techniques to be used for patients
� 1. kVp
� 2. Image receptors for each size breast
� 3. Target-filter combinations (Mo/Mo, Mo/RH, and
Rh/Rh)
Orientation Program
� 4. Average glandular dose
� 5. Information on proper compression
� 6. Positioning
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The QA Manual
� Reference for any staff member
� Reference for patients about the program
� Enough information to run the program
� Conduct any QC test
� Document any procedure
� Demonstrate compliance with any regulation
REMEMBER:
� An important aspect of the QA program is
assessing the effectiveness of the
mammography program.
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QA/QC
� A QA program is designed to optimize the
facility.
� One very important part of the QA program is
Quality Control.
� Quality Control is defined as a series of tests
and tasks that ensure high-quality imaging
� Four steps involved in optimizing a facility.
� 1. Acceptance testing� Look for defects in new or repaired equipment
� 2. Establish a baseline
� 3. Detect changes in equipment performance before it
effects image quality
� 4. Verify that the necessary corrections have been
made
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Remember
� The QA program is a “Team Approach”
� and everyone is working towards the end result -
Quality Images.
� An effective QA program will not eliminate
problems
� It will allow the identification of problems before
they affect the images.
� A well run QC program will provide a
reference that gradual or subtle problems can
be identified, isolated, and corrected.
� This is important since what we are looking
for small and subtle changes in the breast.
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Remember
� With breast tissue, there is little difference in
absorption between healthy tissue and
disease tissue.
Mammography Quality Assurance
� Darkroom Cleanliness
� Processor Quality Control
� Screen Cleanliness
� Phantom Images
� Repeat Analysis
� Fixer Retention
� Darkroom Fog
� Film-screen Contact
� Compression
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� To minimize artifacts on mammography images
by maintaining a clean environment in the
darkroom.
� Frequency: Daily
� Smoking and eating in the darkroom should be
prohibited
� Keep hands clean
� No extraneous material in the darkroom
DARKROOM
CLEANLINESS
FACILITY CLEANLINESS
� Establish and implement protocols for
cleaning and maintaining darkrooms, screens,
and viewboxes
� The facility shall document that cleaning
procedures are performed at the frequency
established in the policy and procedure
manual.
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PROCESSOR QUALITY CONTROL
� To confirm and verify that the processor and
chemistry system is working in a consistent
manner.
� Frequency: daily
� Each day that mammograms are processed
� before any images are processed.
Processor Quality Control
� The test includes an assessment of base plus
fog, mid-density, and density difference.
� The mammography film used at the facility is
used to conduct this test
� Establish operating levels after cleaning the
processor and adding fresh chemistry
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� The base plus fog shall be within +0.03 of the
established operating level.
� The mid-density shall be within +/- 0.15 of the
established operating level.
� The density difference shall be within +/- 0.15 of
the established operating level.
PROCESSOR QUALITY CONTROL
� Done to assure that film optical density, contrast
(density difference), uniformity, and image
quality are maintained at optimum levels
� Frequency: weekly
PHANTOM IMAGES
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Phantom Images
� A mammographic phantom is used
� The cassette and film used are the same as
used clinically for mammography.
� Use the same cassette each time to eliminate
inconsistent results.
Phantom Images
• The Phantom
• a device used to attenuate the x-ray beam in a way that is similar to a typical compressed breast and simulate breast tissue pathology.
• A mammography phantom contains test objects that are similar to microcalcifications, fibers, and masses.
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Phantom Images
• The x-ray images of the phantom are evaluated
in terms of the number of test objects of each
type that are visualized under standard viewing
conditions.
� A phantom is used to assess image quality and
to detect changes in image quality.
Phantom Images
� The optical density of the film at the center of
the image of the phantom shall be at least
1.20 when exposed under typical conditions
(the same technique used for patients should
be used for the phantom).
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Phantom Images
� The optical density of the film at the center of
the phantom image shall not change by more
than +/-0.20 from the established operating
level.
Phantom Images
� The phantom shall achieve at least the
minimum score established by the
accreditation body.
� In the U.S.
� four fibers
� three speck groups
� three masses
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Phantom Images
� The density difference between the
background of the phantom and an added
test object shall not vary by more than +/-
0.05 from the established operating levels
� Test object
� an acrylic disc-4mm thick, 1cm diameter
� used to assess image contrast
FIXER RETENTION
� To determine the quantity of residual fixer (hypo)
in processed film as an indicator of keeping quality.
� Residual hypo indicates insufficient washing and
considerably degrades image stability.
� Frequency: Quarterly
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FIXER RETENTION
� The stain is compared to a hypo estimator strip.
� The hypo estimator provides estimates of the
amount of residual hypo in the film in units of
grams per square meter
FIXER RETENTION
� The residual fixer shall be no more than 5
micrograms per square cm.
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REPEAT ANALYSIS
� Done to determine the number and cause of
repeated mammograms and rejected films.
� Analysis helps identify way to improve
efficiency and reduce patient exposures.
� Frequency: Quarterly.
� If the total repeat or reject rate changes
by more than 2% from the previous
measured rate, the reason for the
change shall be investigated.
� Corrective action shall be recorded and
the results of the corrective action
assessed.
REPEAT ANALYSIS
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� To assure that the darkroom safelights and
other light sources inside and outside the
darkroom do not fog the mammography film
� Frequency: Semi-annually
DARKROOM FOG
DARKROOM FOG
� Use the mammography film used at the facility
� Make an exposure with the typical techniques using
the mammography phantom
� Place the film on the darkroom countertop, with ½
the film covered, for 2 minutes under typical
darkroom conditions
� The mid-density must be no less than 1.20 O.D.
� The optical density difference between the covered
and uncovered parts of the film shall not exceed
0.05
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DARKROOM FOG
� Typical darkroom conditions:
� If the darkroom uses a safelight for
mammography film, the safelight shall be on
during the test.
FILM-SCREEN CONTACT
� Done to assure optimum contact is maintained
between the screen(s) and film in each cassette
� Frequency: Semi-annually
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FILM-SCREEN CONTACT
� Testing for film-screen contact shall be done
using a 40 mesh copper screen. All
cassettes used at the facility shall be tested.
COMPRESSION
� To assure the mammography unit can
provide adequate compression in either the
manual or power mode.
� Frequency: Semi-annually
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COMPRESSION
� Essential for several reasons:
� Reduces the thickness of tissue and thereby
reduces scatter
� Increases contrast
� Reduces radiation to the breast
� Improves image sharpness
� Minimizes patient motion
� Makes the breast more uniform and abnormalities
easier to interpret.
COMPRESSION
� A compression force of 25 pounds shall be
provided.
� The maximum compression shall be between
25 pounds and 45 pounds.
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ANNUAL MEDICAL PHYSICIST
TESTING
� Automatic Exposure Control (AEC)
� KVP Accuracy
� Focal Spot
� Half Value Layer
� Breast Entrance Air Kerma and AEC Reproducibility
� Dose
� X-ray Light Field Alignment
� Uniformity of Screen Speed
� Artifact Evaluation
� Radiation Output
� To reach us:
Commonwealth of Massachusetts
Radiation Control Program
529 Main Street, Suite 1M2A
Charlestown, MA 02129
617-242-3035
617-242-3457- fax