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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

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???QUESTIONS???