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Resident Physics Series

Resident Physics Series. ACR Mammography Protocols. Mammography QC Manual. Revised Edition, 1999. Radiologist Clinical Image Quality Radiologic Technologist Medical Physicist. Sections. Facility Responsibility. Designate One Lead Interpreting Physician. Radiologist’s Responsibilities.

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Resident Physics Series

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  1. Resident Physics Series ACR Mammography Protocols

  2. Mammography QC Manual Revised Edition, 1999 • Radiologist • Clinical Image Quality • Radiologic Technologist • Medical Physicist Sections

  3. Facility Responsibility • Designate One Lead Interpreting Physician

  4. Radiologist’s Responsibilities • Designate one technologistresponsible for QC • QC tech can delegate responsibilities to others

  5. Lead Physician’s Responsibilities • Ensure technologists have adequate • orientation • based on procedure manual • training • continuing education • Ensure effective QC program

  6. Radiologist’s Responsibilities • Ensure availability of appropriate test equipment • Arrange staffing / scheduling to allow time for QC

  7. Radiologist’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 inconsistentresults

  8. Radiologist’s Responsibilities • Select a medical physicist • administers QC program • performs physicist’s tests • Review physicist’s test results

  9. Radiologist’s Responsibilities • Oversee or designate qualified individual to oversee radiation protection program for • employees • patients • individuals in surrounding area

  10. Radiologist’s Responsibilities • Ensure proper maintenance of records in QC procedures manual • employee qualifications • mammography technique / procedures • quality control / safety / protection • infection control

  11. Radiologist’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.”

  12. Physicist’s Responsibilities • Note: All physicist’s tests are to be done annually or after tube replacement or major service

  13. 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)

  14. 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

  15. Collimation 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

  16. Physicist’s 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. Physicist’s Responsibilities: • Screen Uniformity • compare O.D. of each cassette using phototimer • AEC Reproducibility

  19. Physicist’s 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 > 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. Physicist’s Responsibilities • Viewing conditions • ambient light • viewbox brightness • My experience • Ambient lighting often ignored

  25. Technologist’s 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. Technologist’s ResponsibilitiesMonthly: Visual Checklist • visual checklist • SID indicator • angle indicator • locks • field light • smooth motions

  27. 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

  28. Technologist’s ResponsibilitiesQuarterly • Fixer retention analysis • Fixer affects archivability of films • Repeat analysis • breakdown by cause • motion • positioning • technique • static • etc.

  29. 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

  30. 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

  31. Semi-annual Technologist’s Responsibilities Screen Film Contact

  32. 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

  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

  35. 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.

  36. FDA Inspection Violations (2007)

  37. Why Sites Failed Accreditation2001 - 2003

  38. Units Passing Accreditation2001-2003

  39. Units Passing Accreditation 2003

  40. What is FFDM? • Fly Fishing Democratic Mothers • Far Field Dignified Marketing • Fat Farm for Dumb Maniacs

  41. What is FFDM? • Full Field Digital Mammography

  42. How Popular is FFDM

  43. Number of Accredited FFDM Units Nov 03 Nov 07

  44. Is the Overall # of Mammo Units IncreasingorAre these Replacement Units?

  45. Number of Accredited Units Nov 03 Nov 07

  46. The End Questions?

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