Mammography Quality Standards Act MQSA to ensure the safety and reliability of mammography and help detect breast cancer in its earliest most treatable stages Mammography practice under federal control FDA ID: 785568
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Slide1
Resident Physics Series
ACR Mammography Protocols
Slide2Mammography Quality Standards Act (MQSA)
“
to ensure the safety and reliability of mammography and help detect breast cancer in its earliest, most treatable stages
”Mammography practice under federal control (FDA)
1992
Slide3MQSA Requirements
Yearly physics surveys
Yearly FDA inspections
Georgia x-ray regulators on contract with FDAFY 2013No violations: 87%
Slide4Facility Accreditation by “Accrediting Body”
American College of Radiology (ACR)
State of Arkansas
State of IowaState of Texas
Slide5Slide6FDA Facility & Procedure Count
June, 2006
Late 2013
% Change
Total certified facilities
88508691
-1.8
Total accredited units
13588
12195
-10.3
Certified facilities with FFDM units
1027
8004
+679.4
Accredited FFDM units
1455
12195
+738.1
Annual mammography procedures
33,940,037
38,596,266
+13.7
Slide7Number of Accredited FFDM Units
Dec 13
Nov 03
Slide8Number of Accredited Units
Nov 03
Nov
13
Slide9% FFDM Units
Dec 2003
June 2015
Slide10Mammography QC Manual
Radiologist
Clinical Image Quality
Radiologic TechnologistMedical Physicist
Revised Edition, 1999
Sections
Slide11Quality Assurance (QA)
Every imaging procedure is necessary & appropriate to clinical problem at hand
images contain information critical to solution of that problem
QA should ensure
Slide12Quality Assurance (QA)
recorded information is
correctly interpreted
made available to patient’s physician in a timely fashion consistent with image quality objectives, examination results in lowest possible
radiation exposurecostinconvenience to the patient
Slide13Quality Control (QC)
Acceptance Testing
detection of defects in equipment that is newly installed or has undergone major repair
Baselines
Establishment of baseline equipment performancequantitative data when system operating properly
QC is integral part of QA
Slide14Quality Control (QC)
Diagnosis
Diagnosis of changes in equipment performance before they become radiologically apparent
VerificationVerification of correction of causes of deterioration in equipment performance
Slide15Facility Responsibility
Designate
One
Lead Interpreting Physician
Slide16Lead Physician
’
s Responsibilities
Ensure technologists have adequateorientationbased on procedure manual
trainingcontinuing educationEnsure effective QC program
Slide17Radiologist
’
s Responsibilities
Designate one technologist
responsible for QCQC tech can delegate responsibilities
Slide18Radiologist
’
s Responsibilities
Ensure availability of appropriate test equipment
Arrange staffing / scheduling to allow time for QC
Slide19Radiologist
’
s Responsibilities
provide frequent consistent positive & negative feedback to technologists about film quality & QCReview technologist’
s test resultsno less than every 3 monthsmore often if inconsistentresults
Slide20Radiologist
’
s Responsibilities
Select a medical physicistadministers QC programperforms physicist
’s testsReview physicist’s test results
Slide21Radiologist
’
s Responsibilities
Oversee or designate qualified individual to oversee radiation protection program foremployees
patientsindividuals in surrounding area
Slide22Radiologist
’
s Responsibilities
Ensure proper maintenance of records in QC procedures manualemployee qualifications
mammography technique / proceduresquality control / safety / protectioninfection control
Slide23Radiologist
’
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.
”
Slide24Physicists & Digital Mammoraphy
Physicist must insure equipment meets manufacturer
’
s specificationsEquipment specs now defined by manufacturer, not ACR/FDA
Slide25Physicist
’
s Responsibilities
Note: All physicist
’s tests are to be done annually or after tube replacement or major service
Slide26Physicist
’
s Responsibilities: Mammography Unit Assembly Evaluation
mechanical stability / identification of sharp edgesreceptor stability
locks / motions / detentsoperator shieldingthickness scale accuracyindicator lights workingtechnique chart posted (see next slide)
Slide27Technique Chart
Even though most mammo is phototimed, still need technique chart
For given breast size, density, view specify machine set-up
Phototimer mode (auto standard, contrast, dose, …)Density (-2, -1, 0, …)
Slide28Technique Chart
Wrong (my opinion)
Display kVp, mAs, target, filter calculated by machine for given image
Correct (my opinion)
Display machine settings selectable by technologist for this breast and viewShould provide enough guidance to allow a technologist who has not worked in this room or facility to properly set up a study
Slide29Physicist
’
s Responsibilities: Mammography Unit Assembly Evaluation
Cassettes slide smoothly into/out of holderOverride available for auto-decompression
display must indicate when auto-decompression turned offManual release of compression if power lost
FilmCR
Slide30Collimation Assessment
x-ray light field alignment
beam does not exceed receptor by > 2% SID
compression paddle / receptor alignment at chest wall within 1% SIDpaddle not visible on image
Image should fill filmMany units by design will not do this
Film
Slide31Physicist
’
s Responsibilities
Focal Spot Performancelimiting resolution pattern
kVp accuracy / reproducibilityBeam quality (HVL)minimum &
maximumminimum: patient dosemaximum: image contrast
Slide32Automatic Exposure Control (AEC / Phototiming)
kVp tracking
Thickness tracking
image mode tracking (cassette sizes, w w/o grid)
automatic mode trackingunit selects kVp, target, filterdensity controleven steps of ~ 15-20%
Slide33Physicist
’
s Responsibilities:
Screen Uniformitycompare O.D. of each cassette using phototimerAEC Reproducibility
Film
Slide34Physicist
’
s Responsibilities
Breast Entrance Exposure, Average Glandular Dose, RMI-156 “
accreditation” phantom used for entrance exposure / average glandular dose
Slide35Breast Average Glandular Dose Limits
0.3 rad (300 mrads, 3 mGy) maximum per view for screen-film receptors using a grid
Same for film and digital
0.1 rad (100 mrads, 1 mGy) maximum per view for non-grid screen-film receptors
Radiation output rate > 800 mR/sec
Slide36Image Quality Evaluation
use RMI-156
“
accreditation” phantomrecord
fibersspeck groupsmassesoptical densitiestechnique
Slide37A Poor Phantom Image
Slide38Artifact Identification
Artifact evaluation / description
Done with phantom
Slide39Physicist
’
s Responsibilities
Viewing conditionsambient lightviewbox brightness
My experienceAmbient lighting often ignored
Film
Slide40Technologist
’
s Responsibilities
Dailydarkroom cleanliness
processor quality controlsensitometric dataWeekly
screen cleanlinessviewboxes and viewing conditionsPhantom images
All QC must not only be performed but must be
documented
!
Film
Film
Slide41Technologist
’
s Responsibilities
Monthly: Visual Checklistvisual checklist
SID indicatorangle indicatorlocksfield lightsmooth motions
Slide42Technologist
’
s Responsibilities
Monthly: Visual Checklistcassette lock
Is cassette held firmed in place when tubestand tiltedCompression device & firm compressionSmooth edgesHolds pressure
hand switch placementvisibilityswitches/ lights/ meterscones/ collimators
Slide43Technologist
’
s Responsibilities
QuarterlyRepeat analysis
breakdown by causemotionpositioningtechniquestaticetc.
Slide44Semi-Annual Technologist
’
s Responsibilities
Compressioncan use bathroom scale covered with towel
25 - 40 pounds for automatic systemsat least 25 pounds for manual compression
Slide45The End
Questions?