Resident Physics Series

ACR Mammography Protocols

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)

19921992

MQSA Requirements

Yearly physics surveysYearly FDA inspections

Georgia x-ray regulators on contract with FDAFY 2013

No violations: 87%

Facility Accreditation by “Accrediting Body”

American College of Radiology (ACR)State of ArkansasState of IowaState of Texas

FDA Facility & Procedure CountJune, 2006 Late 2013 %

Change

Total certified facilities

8850 8691 -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

Number of Accredited FFDM Units

Jun 11Jun 11Nov 03Nov 03

Number of Accredited Units

Jun 11Jun 11Nov 03Nov 03

% FFDM Units

Dec 2003Dec 2003

Jun 2011Jun 2011

FDA-Approved FFDM Units Last 5 YearsDate Manufacture

rModel

6/15/11

Hologic Selenia Encore Direct

4/28/11

Sectra MicroDose Mammography L30 Photon Counting

2/11/11

Hologic Selenia Dimensions Digital Breast Tomosynthesis (DBT)

Direct

2/11/11

Siemens Mammomat Inspiration Direct

11/3/10

Carestream Directview Computed Radiography (CR) CR

2/11/09

Hologic Selenia Dimensions 2D Direct

2/11/09

Hologic Selenia S Direct

2/11/09

Siemens Mammomat Novation S Direct

11/2007

Hologic Selenia with Tungsten target Direct

07/10/06

Fuji Computed Radiography Mammography Suite

CR

04/11/06

General Electric

Senographe Essential Indirect

Mammography QC Manual

RadiologistClinical Image QualityRadiologic TechnologistMedical Physicist

Revised Edition, 1999Revised Edition, 1999

SectionsSections

Quality Assurance (QA)

Every imaging procedure is necessary & appropriate to clinical problem at hand

images contain information critical to solution of that problem

QA should ensureQA should ensure

Quality Assurance (QA)recorded information is

correctly interpretedmade available to patient’s physician in a

timely fashion consistent with image quality objectives,

examination results in lowest possibleradiation exposurecostinconvenience to the patient

Quality Control (QC)

Acceptance Testingdetection of defects in equipment that is

newly installed or has undergone major repair

BaselinesEstablishment of baseline equipment

performance quantitative data when system operating properly

QC is integral part of QAQC is integral part of QA

Quality Control (QC)

DiagnosisDiagnosis of changes in equipment

performance before they become radiologically apparent

VerificationVerification of correction of causes of

deterioration in equipment performance

Facility Responsibility

Designate One Lead Interpreting Physician

Lead Physician’s Responsibilities

Ensure technologists have adequateorientation

based on procedure manualtrainingcontinuing education

Ensure effective QC program

Radiologist’s Responsibilities

Designate one technologist responsible for QC

QC tech can delegate responsibilities

Radiologist’s Responsibilities

Ensure availability of appropriate test equipment

Arrange staffing / scheduling to allow time for QC

Radiologist’s Responsibilities

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

Review technologist’s test resultsno less than every 3 monthsmore often if inconsistent

results

Radiologist’s Responsibilities

Select a medical physicistadministers QC programperforms physicist’s tests

Review physicist’s test results

Radiologist’s Responsibilities

Oversee or designate qualified individual to oversee radiation protection program foremployeespatientsindividuals in surrounding area

Radiologist’s Responsibilities

Ensure proper maintenance of records in QC procedures manualemployee qualificationsmammography technique / proceduresquality control / safety / protectioninfection control

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.”

“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 Proliferation of Digital MammographyTotal mammography units in US (10/1/2010)

12,445Total digital mammography units (10/1/2010

8748 (70.3%)Total digital mammography units (4/1/2010

or 6 months ago)8195 (65.2%)

Increase in digital units~ 92/month

Physicists & Digital MammoraphyPhysicist must insure equipment meets

manufacturer’s specificationsEquipment specs now defined by

manufacturer, not ACR/FDA

Physicist’s Responsibilities

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

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

mechanical stability / identification of sharp edges

receptor stabilitylocks / motions / detentsoperator shieldingthickness scale accuracyindicator lights workingtechnique chart posted (see next

slide)

Technique ChartEven though most mammo is

phototimed, still need technique chartFor given breast size, density, view

specify machine set-upPhototimer mode (auto standard,

contrast, dose, …)Density (-2, -1, 0, …)

Technique 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 view

Should provide enough guidance to allow a technologist who has not worked in this room or facility to properly set up a study

Physicist’s Responsibilities: Mammography Unit Assembly Evaluation

Cassettes slide smoothly into/out of holderOverride available for auto-decompression

display must indicate when auto-decompression turned off

Manual release of compression if power lost

Collimation Assessment

x-ray light field alignmentbeam does not exceed receptor

by > 2% SIDcompression paddle / receptor

alignment at chest wall within 1% SIDpaddle not visible on image

Image should fill filmMany units by design will not do this

Physicist’s Responsibilities

Focal Spot Performancelimiting resolution pattern

kVp accuracy / reproducibility

Beam quality (HVL)minimum & maximum

minimum: patient dose maximum: image contrast

Automatic Exposure Control (AEC / Phototiming)kVp trackingThickness trackingimage mode tracking (cassette sizes, w

w/o grid)automatic mode tracking

unit selects kVp, target, filterdensity control

even steps of ~ 15-20% Density Step Changes

0

2

4

6

8

10

12

14

16

18

-5 -4 -3 -2 -1 0 1 2 3 4 5

Step

% C

han

ge

Series1

Physicist’s Responsibilities:

Screen Uniformitycompare O.D. of each cassette using

phototimerAEC Reproducibility

Physicist’s Responsibilities

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

entrance exposure / average glandular dose

Breast Average Glandular Dose Limits

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

Image Quality Evaluationuse RMI-156 “accreditation” phantomrecord

fibersspeck groupsmassesoptical densitiestechnique

A Poor Phantom Image

Artifact Identification

Artifact evaluation / descriptiondetermination of artifact source

processor other equipment

Done with phantomfilm

Physicist’s Responsibilities

Viewing conditionsambient lightviewbox brightness

My experienceAmbient lighting

often ignored

Technologist’s Responsibilities

Dailydarkroom cleanlinessprocessor quality control

sensitometric data

Weeklyscreen cleanlinessviewboxes and viewing

conditionsPhantom images

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

Speed

1.11

1.31

1.51

6/2/

97

6/3/

97

6/4/

97

6/5/

97

6/6/

97

6/9/

97

6/10

/97

6/11

/97

6/12

/97

6/13

/97

6/16

/97

6/17

/97

6/18

/97

6/19

/97

6/20

/97

6/23

/97

6/24

/97

6/25

/97

6/26

/97

6/27

/97

6/30

/97

7/1/

97

7/2/

97

7/3/

97

7/7/

97

7/8/

97

7/9/

97

7/10

/97

7/11

/97

7/14

/97

O.D

.

Technologist’s ResponsibilitiesMonthly: Visual Checklist

visual checklistSID indicatorangle indicatorlocksfield lightsmooth motions

Technologist’s ResponsibilitiesMonthly: Visual Checklist

cassette lockIs cassette held firmed in place when tubestand

tilted

Compression device & firm compressionSmooth edgesHolds pressure

hand switch placementvisibilityswitches/ lights/ meterscones/ collimators

Technologist’s ResponsibilitiesQuarterly

Fixer retention analysisFixer affects

archivability of filmsRepeat analysis

breakdown by cause motion positioning technique static etc.

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 ResponsibilitiesScreen Film Contact

40 lines/inch Copper meshsubjective resultspoor contact can result if time (15 minutes)

not provided for air to bleed out of cassette after closingNOTE: 15 minutes between cassette loading

& exposure must be provided for all clinical films to insure good contact

Semi-annual Technologist’s ResponsibilitiesScreen Film Contact

Semi-Annual Technologist’s Responsibilities

Compressioncan use bathroom scale covered with

towel25 - 40 pounds for automatic systemsat least 25 pounds for manual

compression

The End

Questions?