1 MAMMOGRAPHY QAMAMMOGRAPHY QA

Quality Assurance, Quality Quality Assurance, Quality ControlControl

& Equipment& Equipment

Bushong Bushong Ch. 19 & 20Ch. 19 & 20

Rev. Spring 2009/2010

PURPOSE OF QCPURPOSE OF QCASSURES OPTIMUM PATIENT ASSURES OPTIMUM PATIENT

CARECARE by avoiding unnecessary repeat by avoiding unnecessary repeat

exposures due to artifacts, exposures due to artifacts, processing problems and processing problems and

equipment failureequipment failure

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2 MQSA National Statistics

Total annual mammography procedures reported, as of March 1, 20101

38,057,377

  Percent of inspections with no violation 80.2%

Certification statistics, as of March 1, 2010   12,623

Certified facilities with FFDM2 units / Accredited FFDM units

5,402 / 7,963

 

•FEDERAL LEGISLATION•OCT. 1, 1994•EQUIPMENT DESIGN & OPERATION STANDARDS (DEDICATED UNITS)•INTENSIVE QUALITY CONTROL PROGRAM

WHAT DOES MQSA REPRESENT? __________________

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Quality controlQuality control is an equipment and processing is an equipment and processing evaluation program in diagnostic imaging evaluation program in diagnostic imaging centers.centers.

QC involves testingQC involves testing, record keeping and , record keeping and evaluation of imaging equipment and processingevaluation of imaging equipment and processing

QC Team includesQC Team includes Radiographer/Mammographer, Physicists and Radiographer/Mammographer, Physicists and RadiologistRadiologist

QA involves peopleQA involves people – scheduling, reports, waiting – scheduling, reports, waiting time and follow up examstime and follow up exams

““double reads” double reads”

MAMMO & Quality MAMMO & Quality ControlControl

See Bushong – CH. 20 PG 333

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4Elements of QC Elements of QC pg 333pg 333

TASKSTASKS Darkroom CleanDarkroom Clean Processor QC – Processor QC –

sensitometry/densitometrsensitometry/densitometry and DEVELOPER tempy and DEVELOPER temp

Screen CleaningScreen Cleaning VISUAL CHECKVISUAL CHECK Phantom ImagesPhantom Images Repeat Analysis Repeat Analysis (should (should

be less than 2% repeat rate - be less than 2% repeat rate - diagnostic rad = 5%)diagnostic rad = 5%)

FREQUENCYFREQUENCY DailyDaily

WeeklyWeekly

Monthly/Monthly/QuarterlyQuarterly

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5 MAMMO QCMAMMO QCSEMIANNUALLYSEMIANNUALLY DARKROOM FOGDARKROOM FOG SCREEN/FILM SCREEN/FILM

CONTACTCONTACT COMPRESSIONCOMPRESSION

NOT MORE THAN NOT MORE THAN 40 PSI40 PSI

(25 PSI(25 PSI

is average)is average)

MONTHLY Checks

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6 QUALITY CONTROL QUALITY CONTROL TOOLSTOOLS

PHANTOMPHANTOM DIGITAL THERMOMETERDIGITAL THERMOMETER SCREEN CLEANERSCREEN CLEANER LINT FREE CLOTHSLINT FREE CLOTHS FIXER RETENTION TESTING KITFIXER RETENTION TESTING KIT CHARTSCHARTS

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7 Hypo RetentionHypo RetentionChecks for what?Checks for what?

Fixer left on film Fixer left on film – “Archival Properties”– “Archival Properties”

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WIRE MESH WIRE MESH

Checks for what

How long should you wait after loading a cassette to use it?

15 min & placed in an upright position

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9Types of Types of

Safelights?Safelights?

Wratten 6bWratten 6b GBXGBX Check for leaks/cracks?Check for leaks/cracks?

How often?

Bulb Wattage?

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For those still using film…For those still using film…clean crossovers dailyclean crossovers daily

Use “dedicated” Use “dedicated” processor for only processor for only

mammomammo

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These specks were produced by flakes trapped between the film and the screen –

Not calcifications in the breast

DAILY QUALITY CONTROL

DARKROOM CLEANLINESS

WIPE COUNTERSDUST VENTS & LIGHTS

PROCESSORQUALITY CONTROL

Sensitometer stripDensitometer step

PHANTOM IMAGEAssures quality control of Radiographic Image

&graph results

VISUAL VISUAL

CHECKLISTCHECKLIST

MONTHLYMONTHLY

FIXER FIXER RETENTION RETENTION

MONTHLYMONTHLY

REPEATREPEAT

ANALYSISANALYSIS

DARKROOMDARKROOM

FOGFOG

SEMI-SEMI-ANNUALANNUAL

FILM/SCREENFILM/SCREEN

CONTACTCONTACT

SEMI-ANNUALSEMI-ANNUAL

COMPRESSIOCOMPRESSIONN

(25 PSI)(25 PSI)

SEMI-ANNUALSEMI-ANNUAL

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12 PHANTOM IMAGESPHANTOM IMAGES Daily - to assure film Daily - to assure film

density, contrast, density, contrast, uniformity and image uniformity and image quality are optimum – quality are optimum – Using the SAME Using the SAME cassette and technical cassette and technical factors each timefactors each time

4/5 masses 3/4specks 4/6 fibers should be seen (see pg 500 review book)

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REPEAT ANALYSISREPEAT ANALYSIS

Mammography should be less than Mammography should be less than 22%%

Number of repeated filmNumber of repeated film Repeat Rate = --------------------------- X 100Repeat Rate = --------------------------- X 100 Total # of filmsTotal # of films

Diagnostic Radiology = less than 5%Diagnostic Radiology = less than 5% Students = less than 10 %Students = less than 10 %

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15 Mammography Mammography EquipmentEquipment

Bushong – Ch. 19Bushong – Ch. 19

FILM FILM SCREEN SCREEN

& DIGITAL& DIGITAL

When the x-ray tube is tilted in its housing, the effective focal spot is small, the x-ray intensity is more uniform, and tissue against the chest is imaged.

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16 EQUIPMENT EQUIPMENT DIFFERENCESDIFFERENCES

TARGET TARGET MATERIAL –MATERIAL –

MOLYBDENUMMOLYBDENUM MO/RHODIUMMO/RHODIUM SMALLER SMALLER

FOCAL SPOTSFOCAL SPOTS SHORTER SIDSHORTER SID

KVP RANGESKVP RANGES LOW ~ 24 – 30 LOW ~ 24 – 30

23 – 28 23 – 28 (Bushong)(Bushong) (type of target (type of target

used)used) MASMAS PHOTOCELLSPHOTOCELLS

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17 Mammography Imaging Mammography Imaging SystemSystem

High frequency generatorsHigh frequency generators TARGET MATERIAL:TARGET MATERIAL:

Tungsten (W), (z = ____?) Tungsten (W), (z = ____?) 7474

Molybdenum (Mo), (z = ___ ?) Molybdenum (Mo), (z = ___ ?) 4242

or rhodium (Rh) target (z = ___ ?) or rhodium (Rh) target (z = ___ ?) 4545

Focal spot sizes Focal spot sizes 0.3/0.1 mm0.3/0.1 mm (Bushong)(Bushong)

with tilted tubewith tilted tube Maximum 600 mAs limitMaximum 600 mAs limit

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18 Mammography Imaging Mammography Imaging SystemSystem

Inherent filtration Inherent filtration 0.1 Al0.1 Al equivalent equivalent

Heel effect used to advantageHeel effect used to advantage Compression Compression reduces motion, reduces motion,

improves spatial resolution, improves spatial resolution, lowers patient doselowers patient dose

High-transmission cellular High-transmission cellular gridgrid

Automatic exposure controlAutomatic exposure control

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19 DEDICATED MAMMOGRAPIC EQUIPMENT

KVP RANGE : 23 – 28 kvp (BUSHONG)

TARGETS: Molybdenum / Rhodium (vs. Tungsten)

FOCAL SPOTS

(can range from 0.1 – 0.6)

SID 60 –70 cm (vs. 100cm)

Compression Paddle

Heel Effect (fat/cat)

GRIDS : 4:1 or 5:1 (vs 8 to16:1)

What does “DEDICATED”

Mean in the above title?

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20Anode Heel Effect –

Which portion should

Be under the cathode

Side of the TUBE?

The heel effect can be used to advantage in mammography by positioning the cathode toward the chest wall to produce

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DIGITAL MAMMODIGITAL MAMMO DIGITAL has a DIGITAL has a

resolution of resolution of approximately approximately

5 lp/mm5 lp/mm – but also has – but also has MORE CONTRASTMORE CONTRAST

CONVENTIONAL CONVENTIONAL FILM/SCREEN: FILM/SCREEN: resolution of resolution of approximately approximately 12 12 lp/mmlp/mm

No need for an additional exposure to the patient

22 MAMMOGRAPHIC IMAGESMAMMOGRAPHIC IMAGES

The BREAST has a low subject The BREAST has a low subject contrast – little differences in contrast – little differences in

density = soft tissue radiographydensity = soft tissue radiography

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23 Compression in mammography has three Compression in mammography has three principal advantages: improved spatial principal advantages: improved spatial resolution, improved contrast resolution, and resolution, improved contrast resolution, and lower patient dose.lower patient dose.

Can affect:

kVp & mAs ranges

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24 •A high-transmission cellular grid designed specifically for mammography.

•4:1 or 5:1 grid ratio

•40 line/cm frequency

•4:1 grid doubles pt dose –

•but improves contrast significantly p 327

•Correct way to load mammography film and position the cassette. •Spatial resolution improves when the x-ray film is placed closest to the breast and •between the x-ray tube and the radiographic intensifying screen.

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Position of AEC

over breast tissue

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Remove all ambient light when possible – for better images

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28 Risk Factors for Breast Risk Factors for Breast CancerCancer

Age: Age: the older you are, the higher the riskthe older you are, the higher the risk Family history: Family history: mother, sister with breast cancermother, sister with breast cancer Genetics: Genetics: presence of presence of BRCA1BRCA1 or or BRCA2BRCA2 genes genes Breast architectureBreast architecture; dense breast tissue; dense breast tissue Menstruation: Menstruation: onset before age 12onset before age 12 Menopause: Menopause: onset after age 55onset after age 55 Prolonged use of Prolonged use of estrogenestrogen Late age at birth of first childLate age at birth of first child or or no childrenno children Education: Education: risk increases with higher educationrisk increases with higher education SocioeconomicsSocioeconomics: risk increases with higher : risk increases with higher

status status