mammography and acr protocols

GeorgeDavid

Resident Physics SeriesResident Physics Series

ACR Mammography Protocols

GeorgeDavid

Mammography QC ManualMammography QC Manual

• Radiologist

• Clinical Image Quality

• Radiologic Technologist

• Medical Physicist

Revised Edition, 1999Revised Edition, 1999

SectionsSections

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Facility ResponsibilityFacility Responsibility

• Designate One Lead Interpreting Physician

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• Designate one technologist responsible for QC

• QC tech can delegate responsibilities to others

Lead Physician’s Responsibilities

Lead Physician’s Responsibilities

• Ensure technologists have adequate orientation

» based on procedure manual

training continuing education

• Ensure effective QC program

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• Ensure availability of appropriate test equipment

• Arrange staffing / scheduling to allow time for QC

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• provide frequent consistent positive & negative feedback to technologists about film quality & QC

• Review technologist’s test results no less than every 3 months more often if inconsistent

results

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• Select a medical physicist administers QC program performs physicist’s tests

• Review physicist’s test results

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• Oversee or designate qualified individual to oversee radiation protection program for employees patients individuals in surrounding area

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• Ensure proper maintenance of records in QC procedures manual employee qualifications mammography technique / procedures quality control / safety / protection infection control

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Radiologist’s ResponsibilitiesRadiologist’s Responsibilities

• “The radiologist is ultimately responsible for the quality of films produced under his or her direction and bears ultimate responsibility for both proper QC testing and QA procedures in mammography.”

• “The radiologist is ultimately responsible for the quality of films produced under his or her direction and bears ultimate responsibility for both proper QC testing and QA procedures in mammography.”

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Physicist’s ResponsibilitiesPhysicist’s Responsibilities

• Note: All physicist’s tests are to Note: All physicist’s tests are to be done be done annuallyannually or after tube or after tube replacement or major servicereplacement or major service

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

• mechanical stability / identification of sharp edges

• receptor stability

• locks / motions / detents

• operator shielding

• thickness scale accuracy

• indicator lights working

• technique chart posted (see next slide)

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

• Cassettes slide smoothly into/out of holder

• Override available for auto-decompression display must indicate when auto-decompression

turned off

• Manual release of compression if power lost

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Collimation AssessmentCollimation Assessment

• x-ray light field alignment• beam does not exceed receptor by >

2% SID• compression paddle / receptor

alignment at chest wall within 1% SID paddle not visible on image

• Image should fill film Many units by design will not do this

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Physicist’s ResponsibilitiesPhysicist’s Responsibilities

• Focal Spot Performance limiting resolution pattern

• kVp accuracy / reproducibility

• Beam quality (HVL) minimum & maximum

» minimum: patient dose» maximum: image contrast

Automatic Exposure Control (AEC / Phototiming)

Automatic Exposure Control (AEC / Phototiming)

• kVp tracking• Thickness tracking• image mode tracking (cassette sizes, w

w/o grid)

• automatic mode tracking unit selects kVp, target, filter

• density control even steps of ~ 15-20%

Density Step Changes

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Physicist’s Responsibilities:Physicist’s Responsibilities:

• Screen Uniformity compare O.D. of each cassette using

phototimer

• AEC Reproducibility

Physicist’s ResponsibilitiesPhysicist’s Responsibilities

• Breast Entrance Exposure, Average Glandular Dose, RMI-156 “accreditation” phantom used for entrance

exposure / average glandular dose

Breast Average Glandular Dose Limits

Breast Average Glandular Dose Limits

• 0.3 rad (300 mrads, 3 mGy) maximum per view for screen-film receptors using a grid

• 0.1 rad (100 mrads, 1 mGy) maximum per view for non-grid screen-film receptors

• Radiation output rate > 800 mR/sec

Image Quality EvaluationImage Quality Evaluation• use RMI-156 “accreditation”

phantom

• record fibers speck groups masses optical densities technique

A Poor Phantom ImageA Poor Phantom Image

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Artifact IdentificationArtifact Identification

• Artifact evaluation / description determination of artifact source

» processor

» other equipment

• Done with phantomfilm

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Physicist’s ResponsibilitiesPhysicist’s Responsibilities

• Viewing conditions ambient light viewbox brightness

• My experience Ambient lighting

often ignored

Technologist’s ResponsibilitiesTechnologist’s Responsibilities

• Daily darkroom cleanliness processor quality control

» sensitometric data

• Weekly screen cleanliness viewboxes and viewing

conditions Phantom images

All QC must not only be performed All QC must not only be performed but must be but must be documenteddocumented!!

Speed

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O.D

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Technologist’s ResponsibilitiesMonthly: Visual Checklist

Technologist’s ResponsibilitiesMonthly: Visual Checklist

• visual checklist• SID indicator• angle indicator• locks• field light• smooth motions

Technologist’s ResponsibilitiesMonthly: Visual Checklist

Technologist’s ResponsibilitiesMonthly: Visual Checklist

• cassette lock Is cassette held firmed in place when tubestand tilted

• Compression device & firm compression Smooth edges Holds pressure

• hand switch placement• visibility• switches/ lights/ meters• cones/ collimators

Technologist’s ResponsibilitiesQuarterly

Technologist’s ResponsibilitiesQuarterly

• Fixer retention analysis Fixer affects archivability of

films

• Repeat analysis breakdown by cause

» motion» positioning» technique» static» etc.

Semi-Annual Technologist’s Responsibilities: Darkroom Fog

Semi-Annual Technologist’s Responsibilities: Darkroom Fog

• must use sensitized film

» partially cover previously exposed phantom film in darkroom for 2 minutes

• up to .05 O.D. increase acceptable

Semi-annual Technologist’s Responsibilities

Semi-annual Technologist’s Responsibilities

Screen Film Contact

• 40 lines/inch Copper mesh

• subjective results

• poor contact can result if time (15 minutes) not provided for air to bleed out of cassette after closing NOTE: 15 minutes between cassette loading & exposure

must be provided for all clinical films to insure good contact

Semi-annual Technologist’s Responsibilities

Semi-annual Technologist’s ResponsibilitiesScreen Film Contact

Semi-Annual Technologist’s Responsibilities

Semi-Annual Technologist’s Responsibilities

Compression• can use bathroom scale covered

with towel

• 25 - 40 pounds for automatic systems

• at least 25 pounds for manual compression

GeorgeDavid

From the FDAFrom the FDA

FDA Facility & Procedure Count(as of November 1, 2007)

FDA Facility & Procedure Count(as of November 1, 2007)

• Total certified facilities: 8,837 Total accredited units: 13,590

• Certified facilities with FFDM units: 2,434 Accredited FFDM units: 3,644

• Total annual mammography procedures: 35,385,494

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MQSA Violation LevelsMQSA Violation Levels

• Level 1 (Most serious) Example: Unqualified personnel Requires written response within 15 days

• Level 2 May compromise quality of service provided Example: No physics survey within 14 months Requires written response within 30 days

• Level 3 Minor deviations from MQSA standards Example: missing QC records No written response required.

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FDA Inspection Violations (2007)FDA Inspection Violations (2007)

1%16%

7%

76%

Level 1 (most serious)Level 2Level 3No Violation

Why Sites Failed Accreditation2001 - 2003

Why Sites Failed Accreditation2001 - 2003

71.1%

23.1%

5.5%

0.3%

Clinical Images Only

Phantom Images Only

Clinical & PhantomImagesDose

Units Passing Accreditation2001-2003

Units Passing Accreditation2001-2003

86.4%

96.7%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

On 1st Attempt On 2nd Attempt

Units Passing Accreditation 2003

Units Passing Accreditation 2003

88.7% 88.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Initial Accreditation Renewel Accreditation

MQSA Inspections Without Adverse Observations

0102030405060708090

100

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

%

GeorgeDavid

What is FFDM?What is FFDM?

• Fly Fishing Democratic Mothers

• Far Field Dignified Marketing

• Fat Farm for Dumb Maniacs

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What is FFDM?What is FFDM?

• Full Field Digital Mammography

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How Popular is FFDMHow Popular is FFDM

Number of Accredited FFDM Units

Number of Accredited FFDM Units

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Nov 07Nov 03

Is the Overall # of Mammo Units Increasing

orAre these Replacement Units?

Is the Overall # of Mammo Units Increasing

orAre these Replacement Units?

Number of Accredited UnitsNumber of Accredited Units

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Nov 07Nov 03

GeorgeDavid

The EndThe End

Questions?