Slide 1
Slide 2
Introduction
Digital
Mammography
Detector QC
What is FFDM QC and why is it
important?
What to know before you start
Eric A. Berns, Ph.D.
eric.berns@gmail.com
Overview and compare QC tests
Denver Health Medical Center
University of Colorado at Denver and HSC
Denver, CO
Slide 3
Key take home points
Slide 4
Introduction
8,331 SFM Units
July 1, 2008
8,832
Total Accredited
Mammo Units
13,405
Certified
Facilities with
FFDM units
1,991
Accredited
FFDM units
2,926
8,837
Difference
% Units FFDM
Lorad Selenia
App: Oct ‘02
Lorad CCD
App: Mar ‘02
+5
6%
13,450
Siemens Novation
App: Aug ‘04
% Fac w Dig
10%
8%
Total Certified
Mammo
Facilities
Fuji FCRm
App: Jul ‘06
12%
Certified Statistics – Past Year
July 1, 2007
FFDM vs. Date
+45
Fischer Senoscan
App: Sept ‘01
GE Essential
App: Apr ‘06
4%
GE 2000D
App: Jan 2000
2%
3,366
0%
Jul-98
5,119
GE DS
App: Feb 2004
+1,375
Dec-99
Apr-01
Sep-02
Jan-04
May-05
Oct-06
+2,193
1
Slide 5
Slide 6
Introduction
ScreenScreen-Film
MQSA
– Mammography Quality Standards Act
ACR
– American College of Radiology
Slide 7
Slide 8
ScreenScreen-Film
ScreenScreen-Film
2
Slide 9
Slide 10
ScreenScreen-Film
Slide 11
ScreenScreen-Film
Slide 12
ScreenScreen-Film
FFDM
In FFDM, the manufacturer designs and mandates their
own QC program
In FFDM, you must the manufacturers’
manufacturers’ QC program
3
Slide 13
Slide 14
Vs.
RWS
Slide 15
Slide 16
Quality Control: Why?
Reduce exposure to patients and
personnel
Consistent image quality
Detect and correct for potential problems,
before they impact image quality
What is Quality Control?
Determination of what is “Normal”
Normal”
Detection of what is “Abnormal”
Abnormal”
Understanding of how to return to “Normal”
Normal”
from “Abnormal”
Abnormal”
In particular, in FFDM, how do you know
what you are seeing is what it is supposed to
be?
4
Slide 17
Slide 18
Before You Begin QC
Before You Begin
Golden Rules for QC
– Must use manufacturer’
manufacturer’s QC procedures
Obtain proper training & CE credits (8 hours)
• Mandate action limits
– HandsHands-on training on actual unit:
– Manufacturers’
Manufacturers’ QC may refer to Monitor & Printer
• Mechanics
Manufacturers’
Manufacturers’ QC
– Multimodality Workstations have own separate QC
• Software
– Printers may have their own QC
• Artifacts
– Most failures result in stopping clinical imaging
• Learn vendor specific tests and tricks
until failure can be corrected
Slide 19
Slide 20
Before You Begin
Must have proper continuing experience:
– 2 facilities
– 6 units
– Within last 2 years
Before You Begin
Note:
– For new unit:
unit: Must use most current
version
– For renewal unit:
unit: Can use older
version (version used when tested
previously)
5
Slide 21
Slide 22
Before You Begin
Before You Begin
ACR Accreditation - www.acr.org
– Physics forms
• http://acr.org/accreditation/mammography/mammo_qc_forms.aspx
–
–
–
–
–
GE Senographe 2000D, DS, and Essential
Fischer Senoscan
Lorad Selenia
Siemens Novation
Fuji FCRm
Personnel
Equipment
Testing
Tech QC Forms
Equipment Evaluation
Annual Survey Forms
• Note:
Note: if using unit for both screenscreen-film & CR, you must accredit for
both
FDA Accreditation
– www.fda.gov/cdrh/mammography/
www.fda.gov/cdrh/mammography/
– Other vendors when approved
Slide 23
Slide 24
Before You Begin
Summary Forms
GE
Fischer
Fuji
Lorad
Siemens
Film
6
Slide 25
Slide 26
Before You Begin
Before You Begin
•ACR Accreditation – Equipment Evaluation Forms
GE Medical Systems
Report Date
Survey Date
Model
Site
Site
Senographe 2000D
Room ID
Medical Physicist
X-Ray Unit Manufacturer
Medical Physicist's QC Tests
? 2277390-100 Rev 3, 2001
? 2277390-100 Rev 3 + Addendum 2354312-100, 2003
? Mobile 2371698-100 Rev 0, 2003 ? Seno Advantage 2391082-100 Rev 1, 2003
PASS/FAIL/NA
Slide 27
Report Date
Survey Date
Model
SenoScan
Room ID
Signature
Medical Physicist's QC Tests
GE QC manual version(s) at facility (check all that apply):
1. Flat Field (as described in radiologic technologist tests)
2. Image Quality (Phantom) (as described in radiologic technologist tests)
CNR
(required)
Change in CNR =0.2 (NA for Equipment Evaluations)
Fibers Specks Masses
Phantom IQ Test on AWS
(* NA for units with Seno
Phantom IQ Test on RWS – Left*
Phantom IQ Test on RWS – Right*
Advantage workstations)
Phantom IQ Test on Printer
3. MTF Measurement (as described in radiologic technologist tests)
4. AOP Mode and Signal-to-Noise (SNR) (as described in radiologic technologist tests)
5. Collimation Assessment
Deviation between X-ray field and light field is less than 2% of SID
X-ray field does not extend beyond any side of the IR by more than 2% of SID
Chest wall edge of compression paddle doesn't extend beyond IR by more than 1% of SID
6. Evaluation of Focal Spot Performance
Measured performance within acceptable limits for large focal spot
Measured performance within acceptable limits for small focal spot
7. Breast Entrance Exposure, Average Glandular Dose and Reproducibility
Average glandular dose for average breast is below 3 mGy (300 mrad)
Average glandular dose to a 4.2-cm-thick breast on your unit is
mrad
Exposure reproducibility (CV) for R and mAs must be less than 0.05
8. Artifact Evaluation and Flat Field Uniformity
9. Viewing Condition Check and Setting
10. Monitor Calibration
11. Image Quality – SMPTE Pattern
12. Analysis of Review Work Station (RWS) or Seno Advantage Screen Uniformity
(required for Equipment Evaluations and as necessary)
13. kVp Accuracy and Reproducibility
Measured average kVp within ±5%of indicated kVp
kVp coefficient of variation =0.02
14. Beam Quality Assessment (Half-Value Layer Measurement)
15. Radiation Output
Radiation output is =800 mR/s
mR/s
16. Mammographic Unit Assembly Evaluation
Fischer
Date of Installation
Medical Physicist
Signature
? 2277390-100 Rev 1, 2000
? 2371472-100 Rev 0, 2003
MEDICAL PHYSICIST'S MAMMOGRAPHY QC TEST SUMMARY
Full-Field Digital – Lorad
MEDICAL PHYSICIST'S MAMMOGRAPHY QC TEST SUMMARY
Full-Field Digital - Fischer
MEDICAL PHYSICIST'S MAMMOGRAPHY QC TEST SUMMARY
Full-Field Digital – GE Medical Systems
Site
X-Ray Unit Manufacturer
Date of Installation
Fischer QC manual version
at facility (check one) :
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
? P-55943-OMIssue 1, Rev. 000 (2002)
? P-55943-OMIssue 1, Rev. 3 (July 2003)
? P-55943-OM Issue 1, Rev. 1 (April 2003)
? P-55943-OM Issue 1, Rev. 7 (March 2004)
PASS/FAIL/NA
X-Ray Field Size Alignment and Chest Wall Missed Tissue Checks
X-ray field size aligns with field area indicated on breast support within =2% SID
Chest wall edge of the digital image to the ruler reference mark of breast support is =8.5 mm
Compression Paddle Alignment
Compression paddle edges not visible within field of view
Chest wall edge of compression paddle extends beyond image by =1% SID
kVp Accuracy Test
Measured average kVp within ±5% of indicated kVp
kVp coefficient of variation =0.02
Linearity, Reproducibility and Accuracy
Linearity <0.08
Reproducibility <0.035 for each technique
Half-Value Layer and Output
HVL =0.33 mm Al at 30 kVp, 100 mA
Dosimetry – Average Glandular Dose and Output
Average glandular dose for average breast is below 3 mGy (300 mrad)
Average glandular dose to a 4.2-cm-thick breast on your unit is
mrad
Phantom Image Acquisition Test
No obvious artifacts
(ADU values required for both QC and Equipment Evaluations; P/F results are NA for Equipment Evaluations)
Background StDev
within +50/-0 ADU counts of baseline
Background mean
within ±100 ADU counts of baseline
ADU level difference
within ±300 ADU counts of baseline
Image Quality
Largest 4 fibers, 3 speck groups and 3 masses
Fibers Specks Masses
Phantom IQ Test on Review Work Station
System Resolution/Scan Speed Uniformity
Standard imaging mode @ 7 lp/mm: =5 transitions, =10% modulation
High resolution imaging mode @ 11.1 lp/mm: =5 transitions, =5% modulation
Flat Field Test
Flat field test
Deviations between corner ROIs and center within ±20%
Geometric Distortion and Resolution Uniformity
Automatic Decompression Control
System Artifacts
Image Display Monitor(s) Check (review daily log)
Image Viewing Room Illuminance Test (=50 lux)
X-Ray Unit Manufacturer
Date of Installation
Medical Physicist
Lorad
Report Date
Survey Date
Model
Room ID
Signature
Selenia
Medical Physicist's QC Tests
? June 11, 2002
? 9-500-0285, Rev. 004 (2004)
Lorad QC manual version at facility (check one) :
? 9-500-0285, Rev. 003 (2003)
? 9-500-0285, Rev. 002 (2003)
PASS/FAIL
1. Mammographic Unit Assembly Evaluation
Autodecompression can be overidden to maintain compression (& status maintained)
Manual emergency compression release can be activated in the event of power failure
2. Collimation Assessment
Deviation between X-ray field and light field is less than 2% of SID
X-ray field does not extend beyond any side of the IR by more than 2% of SID
Chest wall edge of compression paddle doesn't extend beyond IR by more than 1% of SID
3. Artifact Evaluation
Artifacts were not apparent or not significant
4. kVp Accuracy and Reproducibility
Measured average kVp within ±5% of indicated kVp
kVp coefficient of variation =0.02
5. Beam Quality Assessment - HVL Measurement
Half-value layer is within acceptable lower and upper limits at all kVp values tested
6. Evaluation of System Resolution
Measured performance within acceptable limits
7. Breast Entrance Exposure and Average Glandular Dose
Average glandular dose for average breast is below 3 mGy (300 mrad)
Average glandular dose to a 4.2-cm-thick breast on your unit is
mrad
8. Radiation Output Rate
Radiation output rate is greater than 800 mR/sec
mR/sec
9. Phantom Image QualityEvaluation
5 largest fibers, 4 largest speck groups and 4 largest masses are visible
Phantom image quality scores:
Fibers
Background Optical Density
Disk Optical Density
Specks
Masses
Disk Contrast
Hard copy background density must be =1.20 (with operating level =1.40)
Hard copy density difference over acrylic disk must be =0.35 (with operating level =0.40)
10. Signal-To-Noise Ratio and Contrast-To-Noise Ratio Measurement
Signal-To-Noise Ratio should be equal or greater to 40
SNR
Contrast-To-Noise Ratio should not vary by more than ±15%
CNR
11. Viewbox Luminance and Room Illuminance
Mammographic viewbox is capable of a luminance of at least 3000 cd/sq m (nit)
Room illuminance (viewbox surface as seen by observer) is 50 lux or less
Room illuminance (monitor surface) is 20 lux or less
12. Softcopy Workstation QC
White level performance
Black level performance
Quality level performance
Uniformity performance
Slide 28
Before You Begin
Mammo Unit Evaluation
ScreenScreen-Film Mammo
– Ensure locks, detents, angulation indicators, and
mechanical support devices operate properly
FFDM
– Same
7
Slide 29
Slide 30
Collimation
Collimation
Fuji FCRm
GE
2000D,
DS,
Essential
Fischer
Senoscan
Lorad
Selenia
Siemens
Novation
Same as ScreenScreen-Film
X
X
X
X
X
Multiple target/filter
combo’
combo’s
X
X
ScreenScreen-Film Mammo
– Assure XX-ray field aligns with the light field
– Collimator allows full coverage of receptor
– Chest wall edge of compression paddle aligns with chest
wall of receptor
Multiple paddle
positions
FFDM
– Same
– Multiple targe/filters
targe/filters and/or multiple paddle positions
– Chest Wall Missed Tissue
– Compression Plate Overlap on the Chest Wall Side
Slide 31
X
X
Chest Wall & Missed
Tissue
X
X
X
X
Compression Plate
Overlap on Chest
Wall
X
Slide 32
Limiting Spatial Resolution
Spatial Resolution
ScreenScreen-Film Mammo
Fuji FCRm
– LineLine-pair test tool
GE
2000D,
DS,
Essential
Fischer
Senoscan
Lorad
Selenia
Siemens
Novation
X
X
• Focal spot
FFDM
– LineLine-pair test tool
• Focal spot
• Detector & imaging chain
Same as ScreenScreen-Film
(Focal Spot Eval)
Eval)
Measure using LP
phantom on top of
acrylic
MTF
X
X
X
X
8
Slide 33
Slide 34
GE 2000D, DS, & Essential
GE 2000D
MTF Measurement – Monthly – Raw Image
Focal Spot Evaluation
•Mo/Mo
•Rh/Rh
•Large & Small Spots
(1.5 mag)
mag)
MTF (%) = (Std. Dev.) x 222 / (Mean Dark ROI – Mean Light ROI)
MTF (%) @ 2 lp/mm
lp/mm > 58%
Slide 35
MTF (%) @ 4 lp/mm
lp/mm > 25%
Slide 36
GE 2000D
2000D Addendum: SubSub-system MTF
– Optional replacement for MTF & Focal spot
– No need for film
• Use specific bar pattern & 4.5 cm acrylic block
GE DS & Essential
MTF and CNR Measurement - Weekly
– Test consistency of CNR and ensure
contrast is adequate
• IQST Test tool
• Use ROI tools to calculate subsub-system MTF
• Repeat at 1.8 mag
Action Limit:
– MTF @ 2 lp/mm
lp/mm > 58%, MTF @ 4 lp/mm
lp/mm > 25%
– Change in CNR must not exceed 0.2
9
Slide 37
Slide 38
Lorad & Siemens
Fuji FCRm
Evaluation of System Resolution
System Resolution
– 5-15 lp/mm
lp/mm Test Pattern
– Up to 10 lp/mm
lp/mm Test Pattern
The system limiting spatial resolution must be:
– 4 cm acrylic
> 7 lp/mm
lp/mm
– Parallel & Perpendicular to tube with 33-5
degree angle
The system limiting spatial resolution must be:
> 8 lp/mm
lp/mm + 2 lp/mm
lp/mm (6 to 10 lp/mm)
lp/mm)
Slide 39
Slide 40
AEC Performance
AEC
ScreenScreen-Film Mammo
– Measure optical densities
Fuji FCRm
GE
2000D,
DS,
Essential
Lorad
Selenia
Siemens
Novation
X
X
X
X
X
X
X
X
Fischer
Senoscan
Same as ScreenScreen-Film
• Different thicknesses using clinical modes
• Different density settings ((-2, -1, 0, +1, +2, etc.)
FFDM
– Measure resultant techniques
– Measure signal, exposure, & SNR values
Density Control
Function
X
ACR Reproducibility
X
Image Mode Tracking
X
CNR
X
SNR
10
Slide 41
Slide 42
GE 2000D
GE DS & Essential
DS specific QC tests
AOP Mode and SNR Check
– Variable thicknesses of acrylic
– Std, Auto
– Evaluate:
• Correct techniques?
• Adequate SNR?
Acrylic
Thickness
2.5 cm
TargetFilter
Mo-Mo
Selected
kVp
27 kVp
Selected
mAs
20-60
4.0 cm
Mo-Rh
28 kVp
35-90
6.0 cm
Rh-Rh
32 kVp
– AOP Mode and SNR Check
• Use builtbuilt-in software for image acquisition
2.5 cm
Acrylic
• AOP: STD/Auto
Exposure Parameters
For AOP STD mode oly
Acrylic Thickness
(mm)
4.0 cm
Acrylic
Track/Filter
mAs
kV
25
Mo/Mo
2020-60
26
50
Rh/Rh
4040-90
29
60
Rh/Rh
4545-95
31
35-90
Each “raw”
raw” image must have a measured SNR of
at least 50
Slide 43
SNR must be > 50
6.0 cm Acrylic
Slide 44
Lorad Selenia
Automatic Exposure Control
– AUTOAUTO-FILTER – 2, 4, 6, 8 cm
Siemens Novation
AEC Image Stability and Reproducibility and SNR
– ACR Phantom
– 4 cm ((-5 thru +5, or -3 to +4)
– Use ROI to measure mean pixel value
inside virtual AEC detector
Performance Criteria
– Pixel value should not vary by more
than 10% of mean
– Exposure compensation steps shall
meet requirements in pixel value table
– Mo/Mo, 28 kV, “H”, sensor 1
– Record mAs,
mAs, SNR, Mean, Entrance Exposure (5 times)
Action Limits:
– Coef.
Coef. of Var for mAS and X < 5%
– SNR and Mean shall not vary by + 15% of Mean
11
Slide 45
Slide 46
Siemens Novation DR
Fuji FCRm
AEC Thickness Tracking
Density Control Function
– 2, 4, and 6 cm
– “H” mode
– 4 cm acrylic, ACR phantom technique
– Max deviation = (Max difference / mean value ) * 100
– Repeat at -2, -1, 0, +1, +2 etc. density
– Record mAs
– mAs change should be 5 to 15% per step
Slide 47
Slide 48
Fuji FCRm
Fuji FCRm
Reproducibility & Image Mode Tracking
– 4 cm acrylic with clinical technique
– Position ion chamber in beam
CNR Per Object Thickness
– Record mAs and X
– Repeat 3 times
– CNR using clinical technique for 2 cm
– Repeat in each mode (small, large, mag,
mag, no grid)
– Action Limits:
Limits:
– Repeat for 4 and 6 cm
• Coefficient of variation for Exposure or mAs must not exceed
0.05
• No significant difference in exposure between small and large
bucky when using similar grids
– Action Limits:
Limits:
• CNR of 2 cm relative to 4 cm must be > 100%
• CNR of 6 cm relative to 4 cm must be > 75%
12
Slide 49
Slide 50
Uniformity of Screen Speed &
Detector Performance
ScreenScreen-Film Mammo
Detector Performance
GE
Fuji FCRm
– Measure if OD’
OD’s are consistent
FlatFlat-Field Uniformity
Detector Calibration
Lorad
Selenia
X
X
X
X
X
Siemens
Novation
X
CR Reader Scanner
Performance
X
Dynamic Range
X
– FlatFlat-field uniformity
Primary Erasure
X
– Detector calibration
InterInter-Plate
Consistency
X
– Pixel correction test
Fischer
Senoscan
Same as ScreenScreen-Film
(Screen Uniformity)
– Check for artifacts
FFDM
2000D,
DS,
Essential
Geometric Distortion
X
X
Pixel Correction
– CR Reader Scanner Performance
Slide 51
Ghosting
X
Slide 52
Fuji FCRm
Dynamic Range
– To confirm the dynamic range of reader and plate
– Use 2 & 4 cm acrylic
Fuji FCRm
CR Reader Scanner Performance
– Establish that IP reader & optics do not exhibit scan or
print jitter
– Technique for 6 cm
– NonNon-grid exposure
– View image to determine if 3 regions are visible
– Position rulers in “T” formation
and discernable
– Expose & process
– Action Limit: Image must have smooth borders free
from jagged edges or defects
13
Slide 53
Slide 54
Fuji FCRm
Fuji FCRm
Primary Erasure (Additive & Multiplicative)
– To assess the erasure performance of reader and
InterInter-Plate Consistency
plates
– To confirm xx-ray absorption & SNR consistency
– Additive: Shoot phantom, process, wait 1 minute,
– Expose plates using clinical technique with 4cm
reprocess, change S value to 10X original,
acrylic
inspect for visibility of phantom image
– Multiplicative: Shoot & process phantom, shoot 4
– Record mAS (must be within +10%)
cm acrylic on same cassette, process and inspect
– Calculate SNR (must be within +15%)
for visibility of phantom image
Slide 55
Slide 56
GE 2000D, DS, & Essential
FlatFlat-field uniformity
– Test to ensure detector performance acceptable
• Measures detector uniformity (signal & noise)
• Measures bad pixels
– System automatically calculates pass/fail
Lorad Selenia
Detector Calibration – Weekly
– 4 cm acrylic block – no paddle
– Built in Calibration software
– Follow onon-screen instructions
• Review image for artifacts
• Repeat until you have 8 images
• End calibration
QAP
• Calibration is performed automatically
14
Slide 57
Slide 58
Siemens Novation DR
Detector Uniformity
Siemens Novation
Detector Calibration Test
– Objective: to determine if system
– Make exposure: 28 kV, 50 mAS,
mAS,
was correctly gain calibrated
Mo/Mo
– Select ROI 128 x 128 pixels
– Must be done weekly
– Record measurements in corners
(technologist)
and center
– Follow onon-screen instructions
– Pixel value inside each of 5 ROI’
ROI’s
– Acquire 8 images
shall not differ by more than 10%
– Images should be free of artifacts
of mean
Slide 59
Slide 60
Siemens Novation DR
Pixel Correction Test
– Calibration mode
Artifacts
ScreenScreen-Film Mammo
– Create new pixel map
– Follow onon-screen instructions
– Evaluate cassettes
– Acquire image
– Evaluate image is free from
FFDM
collimator or debris artifacts
– System compiles new pixel map
– System display results – must
meet requirements
– Evaluate detector
– CR: Imaging Plates
15
Slide 61
Slide 62
Artifacts
Artifacts
Fuji FCRm
GE
2000D,
DS,
Essential
Fischer
Senoscan
Lorad
Selenia
Siemens
Novation
X
X
X
X
X
Same as ScreenScreen-Film
Expose Using Acrylic
Slide 63
Slide 64
Artifacts
Image Quality
Artifact evaluation
ScreenScreen-Film Mammo
– ACR Phantom Scores
– Optical Density & Contrast
FFDM
– ACR Phantom Scores
• Pass/fail requirements differ by vendor
– SignalSignal-toto-Noise Ratio (SNR)
– ContrastContrast-toto-Noise Ratio (CNR)
Mo/Mo
Mo/Rh
Mo/Rh
Rh/Rh
16
Slide 65
Slide 66
Image Quality
Fuji FCRm
Image Quality
GE
2000D,
DS,
Essential
Fischer
Senoscan
X
X
Lorad
Selenia
ACR Phantom Imaging
Siemens
Novation
GE & Fischer &
Fuji
Lorad &
Siemens
Fibers
4
5
Specks
3
4
Masses
3
4
Same as ScreenScreen-Film
Manual Techniques
Clinical Technique
X
CNR
X
X
Slide 67
X
X
Partial
X
X
Slide 68
GE 2000D
ACR Phantom Imaging
– Manual technique (Mo/Mo, 26
kVp,
kVp, 125 mAS)
mAS)
– Score the processed image
GE 2000D
ContrastContrast-toto-Noise Test (CNR)
– To examine consistency of CNR
ratio measured over time
– Use the raw image
– + 20% of baseline
– Acquisition workstation
– Each monitor of the RWS
Background ROI
Mass ROI
– Laser imager
CNR = (Mean
(Meanbackground - Meanmass)/SDbackground
17
Slide 69
Slide 70
GE DS & Essential
Lorad Selenia
Phantom Image Quality
Phantom Image Quality
– Select clinical exposure mode (i.e. AUTOAUTO-FILTER)
– Print film
– Manual technique: Rh/Rh,
Rh/Rh, 29 kVp,
kVp, 56 mAs
– Measure background OD and density difference –
MTF and CNR Measurement
Plot on tech worksheets
– Use IQST test tool
• Background must be > 1.20 OD + 0.20
– Use builtbuilt-in software for image acquisition
• DD must be > 0.40 + 0.05
– Score on each Soft Copy Workstation
– Manual technique: Rh/Rh 30 kVp,
kVp, 56 mAs
• 5 fibers
– Results are automatically displayed (pass/fail)
• 4 speck groups
– Same action limits as 2000D
Slide 71
• 4 masses
Slide 72
Siemens Novation DR
Lorad & Siemens
Phantom Image Quality
– Position phantom 1 cm
over chest wall edge
– Select: 28 kV, AECAEC-Auto,
Mo/Mo
– Score on RWS or Film
SNR and CNR Measurements
– SNR at least > 40
– CNR should stay within ±15% of baseline
– Fiber > 5
– Specks > 4
• Obtained during acceptance testing
– Masses > 4
18
Slide 73
Slide 74
Fuji FCRm
kVp
ScreenScreen-Film Mammo
ContrastContrast-toto-Noise Test (CNR)
– Assure that actual kVp is
– To examine consistency of CNR ratio measured over time
– Use 4 cm acrylic & 0.2 mm Al
• Accurate (+
(+ 5% of indicated)
– Manual technique (Mo/Mo, 26 kVp,
kVp, 125 mAs)
mAs)
• Reproducible (Coeff
(Coeff.. Var. < 2%)
– Calculate CNR using software
FFDM
– + 20% of baseline
– Same
Slide 75
Slide 76
HVL
ScreenScreen-Film Mammo
– Assure HVL is adequate to minimize patient
dose
– HVL shall meet FDA’
FDA’s Performance Standards
FFDM
Dose
ScreenScreen-Film Mammo
– Dose for single CC view of ACR phantom shall
not exceed 3.0 mGy per exposure
FFDM
– Same
– Same
Note the lead sheet
19
Slide 77
Slide 78
Viewing & Viewing Conditions
Radiation Output
ScreenScreen-Film Mammo
ScreenScreen-Film Mammo
– System shall be capable of producing a
– Luminance (>
(> 3000 cd/m2)
minimum output of 7.0 mGy/sec
mGy/sec @ 28 kVp
– Room illuminance (< 50 lux)
lux)
Mo/Mo over 3.0 second period
– Viewbox cleaning
FFDM
– Same
FFDM
– S value confirmation
– Same
– Exposure Linearity
Slide 79
Slide 80
Assessing Tech QC
ScreenScreen-Film Mammo
Film Processing
ScreenScreen-Film Mammo
– Measure optical densities
– Assess site’
site’s QC program
– Check that QC tests are properly performed
– Independent checks of tech QC tests
• Density difference, midmid-density, base+fog
• Measures consistency
FFDM
– Manufacturers’
Manufacturers’ recommendations
FFDM
– Same
– Some refer to printer manufacturers’
manufacturers’ recommendations
– Typically identical to ACR SFM Manual
20
Slide 81
Slide 82
Film Processor QC
Fuji FCRm
Follow Printer
Manufacturers QC
If Not, Use Theirs
GE
2000D,
DS,
Essential
Fischer
Senoscan
X
X
X
X
X
X
Follow FFDMs’
FFDMs’ QC
Film Processing
Lorad
Selenia
X
MidMid-Density
Siemens
Novation
X
Wet Processing
Laser Printer
Northwestern Memorial Hospital - Processor ID: 2 - MAR 2006
Mid-Density
Northwestern Memorial Hospital - Processor ID: Kodak 8900 - Oct 2006
Mid-Density
2.30
1.70
MD Step=12
2.20
1.60
2.10
1.50
2.00
1.40
1.90
1.30
1.20
1.80
Mid-Density Upper Control Limit = 1.48
1.10
1.70
Mid-Density Daily Value
1.00
Mid-Density Upper Control Limit = 2.06
1.60
Mid-Density Daily Value Operating Level = 1.33
Mid-Density Daily Value
Mid-Density Lower Control Limit = 1.18
0.90
Mid-Density Daily Value Operating Level = 1.91
1.50
Mid-Density Lower Control Limit = 1.76
0.80
1.40
6
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Slide 84
RWS QC
Follow monitor
manufacturers QC
If Not, Use FFDM’
FFDM’s
Fuji FCRm
GE
2000D,
DS,
Essential
X
X
X
X
X
X
AGFA IMPAX MA3000
Fischer
Senoscan
Lorad
Selenia
Siemens
Novation
–
–
–
–
–
–
–
Clean monitor surface
Measure display white & black
Measure quality level
Measure uniformity
Calibrate displays
View SMPTE pattern
Viewing conditions
GE Seno Advantage
Use FFDM
manufacturers’
manufacturers’s QC
X
X
–
–
–
–
Viewing conditions check and setting
Monitor calibration
Image quality – SMPTE pattern
Analysis of screen uniformity
Siemens MammoReport Plus
–
–
–
–
–
–
–
Geometric distortion
Reflection
Luminance Response
Luminance Uniformity
Resolution
Noise
Overall Evaluation
21
Slide 85
Slide 86
New FDA Hot Topics
Barco
–
–
–
–
I-Guard Check
Quality Level
Display White
Calibration Settings Check
Tungsten w/ Silver or Rhodium
– Calibration:
Calibration: FDA requires all air kerma measuring
Eizo
–
–
–
–
instruments be calibrated to NISTNIST-traceable
Pattern Check
Luminance Check
Grayscale Check
Uniformity Check
standard for at least one targettarget-filter combination in
the mammo x-ray range…
range…,
Planar
–
–
–
–
–
Monitor Cleaning
Viewing Conditions Check
Monitor Calibration Check
Image Quality – SMPTE
Visual Inspection for Display
Defects
Slide 87
– Do not require such a calibration for W/Ag or W/Rh
W/Rh
– May require corrections for solid state instruments
Slide 88
New FDA Hot Topics
Tungsten w/ Silver or Rhodium
– kVp Measurements:
Measurements:
• Scenario 1:
1: If using kVp meter certified for W/Ag or
W/Rh
W/Rh and a mammo calibrated ion chamber, then ok
• Scenario 2:
2: If not, you need to include a correction
factor in kVp measurements obtained from kVp meter
manufacturer, or, by working with service engineer
and comparing measurements
• Scenario 3:
3: If not W certified and using a separate
New FDA Hot Topics
Tungsten w/ Silver or Rhodium
– HVL Measurements:
Measurements:
• Scenario 1:
1: If using integrated solidsolid-state instrument
that is manufactured for W/Ag or W/Rh
W/Rh,, then ok.
• Scenario 2: If using integrated solidsolid-state instrument
that is not manufactured for W/Ag or W/Rh
W/Rh,, then
obtain necessary correction factors.
solidsolid-state probe, then follow scenario 2.
22
Slide 89
Slide 90
New FDA Hot Topics
New FDA Hot Topics
Use of Foam Cushions on FFDM
QC testing for Printers
– FDA recommends using pads for QC
– Follow FFDM manufacturer’
manufacturer’s QC Manual
if used clinically
– Then, follow printer’
printer’s QC manual
– Required if manufacturer’
manufacturer’s QC
– To determine the appropriate testing
manuals specifies the pad be present
during QC
Slide 91
Slide 92
ACR FFDM QC Manual Project
The current ACR QC Manual was written for
screenscreen-film
– Most does not apply to digital
Subcommittee on QA is writing new manual
– Chair - Eric Berns,
Berns, Ph.D.
– Members – Radiologists, technologists, medical physicists, MITA
reps
ACR FFDM QC Manual Project
QC tests
– Will apply to all manufacturers and models
– Fewer tests and written to be “tech friendly”
friendly”
– New phantom to be more applicable to digital (but usable with
screenscreen-film)
– When ready, draft will be sent to manufacturers for their input before
it is final
Standardize QC tests, performance criteria and
When final, ACR will apply for FDA alternative
frequencies across all systems
standard
Clinical section specific to digital issues
Hope to have draft completed by end of 2008
23
Slide 93
Slide 94
Suggestions
Archive QC images periodically on a CD
Perform flatflat-field imaging before phantom
Troubleshooting QC
Repeat test
– Clean plexiglass & move slightly
Questions to ask yourself:
– Are you using the correct image? Raw vs.
Processed?
– Are the ROI’
ROI’s in the correct location?
imaging tests
Perform testing in the morning
Have a system for monitoring the “Auto
ReRe-boot system
Print/Auto Push”
Push” functions
Call service
– ReRe-calibration solves most image quality problems
Slide 95
Slide 96
Key Take Home Points
Obtain relevant handshands-on training
Must perform manufacturer specific QC tests
Artifacts – most problems can be seen here
ReRe-booting and/or rere-calibrating fixes most
problems
Laser Printer
– Dmax at least 3.5 OD
– MidMid-density about 1.5 OD
Key Take Home Points
Review workstation monitors – look at the
clinical images!
– Do they match?
– Appropriate dark and light levels
Be aware of separate QC for printers &
monitors
Know, and be involved with, your site QC
program
24
Slide 97
Slide 98
SAM Questions
Digital Mammography QC
In digital mammography, who
mandates the pass/fail criteria for site
QC?
20% 1. The American College of Radiology
20% 2. The FDA
20% 3. The FFDM unit manufacturer
20% 4. NEMA
20% 5. MQSA
Eric Berns,
Berns, PhD
10
Slide 99
Slide 100
Answer: 3 - The FFDM unit
manufacturer
References
MQSA Regulations 900.12(e)(6)
http://www.fda.gov/CDRH/MAMMOGRA
PHY/frmamcom2.html#s90012
Answer 3: The FFDM unit
manufacturer
Explanation
“the quality assurance program shall be
substantially the same as the quality
assurance program recommended by the
image receptor manufacturer, except that
the minimum allowable dose for screenscreenfilm systems in this section”
section”
25
Slide 101
Slide 102
How do you accredit a Fuji CR
Mammography system which uses
both CR and screenscreen-film on the same
x-ray system?
25% 1.
Answer: 2 – As 2 mammography
units
References
As 1 mammography unit?
http://www.acr.org/accreditation/mammography/
mammo_faq/mammo_faq_mamac.aspx#8.0.1
As 2 mammography units?
You cannot use CR and film on the
same unit.
25% 4. CR is exempt from accreditation
25% 2.
25% 3.
10
Slide 103
Slide 104
What are the minimum passing ACR
phantom scores for the Lorad Selenia for
weekly QC?
Answer: 2 - As 2 mammography
units
Explanation
As of November 15, 2006 facilities using
both screenscreen-film and CR on the same
mammography units must accredit these
2 systems as 2 separate units.
20%
1.
20%
2.
20%
3.
20%
4.
20%
5.
5 Fibers, 4 Speck Groups, 3 Masses
4 Fibers, 3 Speck Groups, 3 Masses
5 Fibers, 4 Speck Groups, 4 Masses
4 Fibers, 4 Speck Groups, 3 Masses
4 Fibers, 4 Speck Groups, 4 Masses
10
26
Slide 105
Slide 106
Answer 3: 5 Fibers, 4 Speck Groups, 4
Masses
Answer 3: 5 Fibers, 4 Speck Groups, 4
Masses
References
Explanation
Hologic.
Hologic. Lorad Selenia Quality Control
Manual MANMAN-00093, Revision 003,
Bedford (MA): Hologic,
Hologic, 2005
The Lorad Selenia QC manual states that the ACR
Phantom minimum passing scores are as
follows:
5 Fibers
4 Speck Groups
4 Masses
Slide 107
Slide 108
To meet the FDA requirement for continuing
experience, how many mammography
facilities and mammography unit surveys
must be performed within the previous 24
months?
20%
1.
20%
2.
20%
3.
20%
4.
20%
5.
6 Facilities and 2 mammography units
4 Facilities and 12 mammography units
2 Facilities and 6 mammography units
1 Facilities and 6 mammography units
2 Facilities and 12 mammography units
10
Answer 3: 2 Facilities and 6 Mammography
Units
References
http://www.fda.gov/CDRH/MAMMOGRAPHY/robohelp/
START.HTM
900.12(a)(3)(iii)(B): Continuing experience. Following
the second anniversary date of the end of the calendar
quarter in which the requirements of paragraphs
(a)(3)(i) and (a)(3)(ii) of this section were completed or
of April 28, 1999, whichever is later, the medical
physicist shall have surveyed at least two
mammography facilities and a total of at least six
mammography units during the 24 months immediately
preceding the date of the facility’
facility’s annual MQSA
inspection or the last day of the calendar quarter
preceding the inspection or any date in between the
two. The facility shall choose one of these dates to
determine the 2424-month period. No more than one
survey of a specific facility within a 1010-month period or
a specific unit within a period of 60 days can be
counted towards this requirement.
27
Slide 109
Answer 3: 2 Facilities and 6 Mammography
Units
Explanation
The FDA requires:
2 Facilities
6 Mammography Units
Within past 24 months
28