Resident Physics Series

1
Resident Physics Series

• ACR Mammography Protocols

2
Mammography QC Manual
Revised Edition, 1999
Sections

• Radiologist
• Clinical Image Quality
• Radiologic Technologist
• Medical Physicist

3
Facility Responsibility

• Designate One Lead Interpreting Physician

4
Radiologists Responsibilities

• Designate one technologist responsible for QC
• QC tech can delegate responsibilities to others

5
Lead Physicians Responsibilities

• Ensure technologists have adequate
• orientation
• based on procedure manual
• training
• continuing education
• Ensure effective QC program

6
Radiologists Responsibilities

• Ensure availability of appropriate test
  equipment
• Arrange staffing / scheduling to allow time for QC

7
Radiologists Responsibilities

• provide frequent consistent positive negative
  feedback to technologists about film quality QC
• Review technologists test results
• no less than every 3 months
• more often if inconsistentresults

8
Radiologists Responsibilities

• Select a medical physicist
• administers QC program
• performs physicists tests
• Review physicists test results

9
Radiologists Responsibilities

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

10
Radiologists Responsibilities

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

11
Radiologists 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.

12
Physicists Responsibilities

• Note All physicists tests are to be done
  annually or after tube replacement or major
  service

13
Physicists 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)

14
Physicists 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

15
Collimation Assessment

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

16
Physicists Responsibilities

• Focal Spot Performance
• limiting resolution pattern
• kVp accuracy / reproducibility
• Beam quality (HVL)
• minimum maximum
• minimum patient dose
• maximum image contrast

17
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

18
Physicists Responsibilities

• Screen Uniformity
• compare O.D. of each cassette using phototimer
• AEC Reproducibility

19
Physicists Responsibilities

• Breast Entrance Exposure, Average Glandular Dose,
  
• RMI-156 accreditation phantom used for entrance
  exposure / average glandular dose

20
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 gt 800 mR/sec

21
Image Quality Evaluation

• use RMI-156 accreditation phantom
• record
• fibers
• speck groups
• masses
• optical densities
• technique

22
A Poor Phantom Image
23
Artifact Identification

• Artifact evaluation / description
• determination of artifact source
• processor
• other equipment
• Done with phantomfilm

24
Physicists Responsibilities

• Viewing conditions
• ambient light
• viewbox brightness
• My experience
• Ambient lighting often ignored

25
Technologists Responsibilities
All QC must not only be performed but must be
documented!

• Daily
• darkroom cleanliness
• processor quality control
• sensitometric data
• Weekly
• screen cleanliness
• viewboxes and viewing conditions
• Phantom images

26
Technologists ResponsibilitiesMonthly Visual
Checklist

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

27
Technologists 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

28
Technologists ResponsibilitiesQuarterly

• Fixer retention analysis
• Fixer affects archivability of films
• Repeat analysis
• breakdown by cause
• motion
• positioning
• technique
• static
• etc.

29
Semi-Annual Technologists 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

30
Semi-annual Technologists 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

31
Semi-annual Technologists Responsibilities

• Screen Film Contact

32
Semi-Annual Technologists Responsibilities

• Compression
• can use bathroom scale covered with towel
• 25 - 40 pounds for automatic systems
• at least 25 pounds for manual compression

33
From the FDA
34
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 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)
37
Why Sites Failed Accreditation2001 - 2003
38
Units Passing Accreditation2001-2003
39
Units Passing Accreditation 2003
40
(No Transcript)
41
What is FFDM?

• Fly Fishing Democratic Mothers
• Far Field Dignified Marketing
• Fat Farm for Dumb Maniacs

42
What is FFDM?

• Full Field Digital Mammography

43
How Popular is FFDM
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Number of Accredited FFDM Units
Nov 03
Nov 07
45
Is the Overall of Mammo Units IncreasingorAre
these Replacement Units?
46
Number of Accredited Units
Nov 03
Nov 07
47
The End

• Questions?