Siemens MAMMOMAT Novation DR Quality Control Manual

Quality Control ManualMAMMOMAT Novation DR

Order No: SPB7-250.623.50.05.24Version 05 / AG 04/07

Siemens AG Medical SolutionsSpecial SystemsHenkestraße 127D-91052 Erlangen

Germany

CONFIDENTIALITY STATEMENT

This document is the confidential property of Siemens AG Medical Solutions.No part of it maybe transmitted, reproduced, published, or used by other

persons without the permission of Siemens AG Medical Solutions.

The original version of this manual was written in the Englishlanguage.

Contents

MAMMOMAT NovationDR 3SPB7-250.623.50.05.24

Table of Contents

List of Tables 9

List of Figures 11

List of Common Abbreviations 13

1. Introduction 15

1.1 Mammography Equipment Evaluation (MEE) - Medical Physicist (MP)........... 15

1.2 Annually or Every Six Months - Medical Physicist (MP) ................................... 15

1.3 Daily - Technologist (T) .................................................................................... 15

1.4 Weekly - Technologist (T)................................................................................. 15

1.5 Technologist (T)................................................................................................ 15

1.6 Soft Copy Viewing Station ................................................................................ 16

1.7 Laser Camera/Printer ....................................................................................... 16

1.8 Frequency of Required Tests - Technologist.................................................... 17

1.9 Recommended Frequency of QC Tests - Medical Physicist ............................ 18

1.10 Important Notes ................................................................................................ 19

1.11 Required Corrective Action............................................................................... 19

1.12 Required Equipment - Annual Survey, MEE .................................................... 20

2. Start Up and Login 21

2.1 Procedure ......................................................................................................... 21

3. Required Tests - Technologist 22

3.1 Phantom Image Quality .................................................................................... 223.1.1 Objective ........................................................................................................................ 223.1.2 Required Equipment....................................................................................................... 223.1.3 Procedure....................................................................................................................... 223.1.4 Analysis .......................................................................................................................... 253.1.5 Performance Criteria and Corrective Action................................................................... 26

Contents

4 Quality Control ManualSPB7-250.623.50.05.24

3.2 Detector Calibration ..........................................................................................273.2.1 Objective......................................................................................................................... 273.2.2 Required Equipment....................................................................................................... 273.2.3 Procedure ....................................................................................................................... 27

3.3 Artifact Detection...............................................................................................303.3.1 Objective......................................................................................................................... 303.3.2 Required Equipment....................................................................................................... 303.3.3 Procedure ....................................................................................................................... 303.3.4 Performance Criteria and Corrective Action ................................................................... 31

3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements ...............................................323.4.1 Objective......................................................................................................................... 323.4.2 Required Equipment....................................................................................................... 323.4.3 Procedure ....................................................................................................................... 323.4.4 Analysis .......................................................................................................................... 343.4.5 Performance Criteria and Corrective Action ................................................................... 34

3.5 Repeat Analysis ................................................................................................353.5.1 Objective......................................................................................................................... 353.5.2 Procedure ....................................................................................................................... 353.5.3 Analysis .......................................................................................................................... 363.5.4 Performance Criteria and Corrective Action ................................................................... 36

3.6 Compression Force...........................................................................................373.6.1 Objective......................................................................................................................... 373.6.2 Required Equipment....................................................................................................... 373.6.3 Procedure ....................................................................................................................... 373.6.4 Performance Criteria and Corrective Action ................................................................... 37

3.7 Printer Check ....................................................................................................383.7.1 Objective......................................................................................................................... 383.7.2 Required Equipment....................................................................................................... 383.7.3 Procedure ....................................................................................................................... 383.7.4 Performance Criteria and Corrective Action ................................................................... 38

4. Initial Checks - Physicist 39

4.1 Site Audit / Evaluation of Technologist QC Program ........................................394.1.1 Objective......................................................................................................................... 394.1.2 Procedure ....................................................................................................................... 39

4.2 Mechanical Inspection ......................................................................................404.2.1 Objective......................................................................................................................... 404.2.2 Procedure ....................................................................................................................... 40

4.3 Acquisition Workstation Monitor Check ............................................................434.3.1 Objective......................................................................................................................... 434.3.2 Required Equipment....................................................................................................... 434.3.3 Procedure ....................................................................................................................... 434.3.4 Performance Criteria and Corrective Action ................................................................... 44

Contents


5. Required Tests - Physicist 45

5.1 Detector Uniformity and Artifact Detection ....................................................... 455.1.1 Objective ........................................................................................................................ 455.1.2 Required Equipment....................................................................................................... 455.1.3 Procedure....................................................................................................................... 455.1.4 Performance Criteria and Corrective Action................................................................... 47

5.2 Collimation, Dead Space and Compression Paddle Position........................... 485.2.1 Objective ........................................................................................................................ 485.2.2 Required Equipment....................................................................................................... 485.2.3 Procedure....................................................................................................................... 485.2.4 Performance Criteria and Corrective Action................................................................... 51

5.3 AEC Thickness Tracking Test .......................................................................... 525.3.1 Objective ........................................................................................................................ 525.3.2 Required Equipment....................................................................................................... 525.3.3 Procedure....................................................................................................................... 525.3.4 Performance Criteria and Corrective Action................................................................... 53

5.4 Spatial Resolution............................................................................................. 545.4.1 Objective ........................................................................................................................ 545.4.2 Procedure....................................................................................................................... 545.4.3 Performance Criteria and Corrective Action................................................................... 55

5.5 SNR, CNR and AEC repeatability .................................................................... 565.5.1 Objective ........................................................................................................................ 565.5.2 Required Equipment....................................................................................................... 565.5.3 Procedure....................................................................................................................... 565.5.4 Analysis .......................................................................................................................... 585.5.5 Performance Criteria and Corrective Action................................................................... 58

5.6 Image Quality and Radiation Dose................................................................... 595.6.1 Objective ........................................................................................................................ 595.6.2 Required Equipment....................................................................................................... 595.6.3 Procedure....................................................................................................................... 595.6.4 Analysis .......................................................................................................................... 615.6.5 Performance Criteria and Corrective Action................................................................... 62

5.7 HVL and Radiation Output................................................................................ 635.7.1 Objective ........................................................................................................................ 635.7.2 Required Equipment....................................................................................................... 635.7.3 Procedure....................................................................................................................... 635.7.4 Calculating HVL.............................................................................................................. 655.7.5 Performance Criteria and Corrective Action................................................................... 65

5.8 Tube Voltage Measurement & Reproducibility ................................................. 665.8.1 Objective ........................................................................................................................ 665.8.2 Required Equipment....................................................................................................... 665.8.3 Procedure....................................................................................................................... 665.8.4 Calculations.................................................................................................................... 675.8.5 Performance Criteria and Corrective Action................................................................... 68

Contents


5.9 Printer Check ....................................................................................................695.9.1 Objective......................................................................................................................... 695.9.2 Required Equipment....................................................................................................... 695.9.3 Procedure ....................................................................................................................... 695.9.4 Performance Criteria and Corrective Action ................................................................... 69

6. Optional Test 70

6.1 Ghost Image Evaluation....................................................................................706.1.1 Objective......................................................................................................................... 706.1.2 Required Equipment....................................................................................................... 706.1.3 Pre Requisites ................................................................................................................ 706.1.4 Procedure ....................................................................................................................... 706.1.5 Performance Criteria and Corrective Action ................................................................... 72

7. Appendix 1 – QC Forms Technologist Tests 73

Test Form 3.1 Phantom Image Quality .....................................................................75Phantom image quality .............................................................................................................. 75

Test Form 3.2 Detector Calibration ...........................................................................77

Test Form 3.3 Artifact Detection................................................................................79Clinically Relevant Artifacts ....................................................................................................... 79

Test Form 3.4 Signal-to-Noise Ratio (SNR) andContrast-To-Noise Ratio (CNR) Measurements........................................................81

Signal-to-Noise Ratio and Contrast-To-Noise Ratio Measurements ......................................... 82

Test Form 3.5 Repeat Analysis .................................................................................83Mammography Repeat Analysis................................................................................................ 83

Test Form 3.6 Compression Force............................................................................85

Test Form 3.7 Printer Check .....................................................................................87Printer Check ............................................................................................................................. 88

8. Appendix 2 – QC Forms Physicist Tests 91

Test Form 4.1 Site Audit / Evaluation of Technologist QC Program .........................93

Test Form 4.2 Mechanical Inspection .......................................................................95Mechanical Inspection and Follow Up ....................................................................................... 95

Test Form 4.3 Acquisition Workstation Monitor Check .............................................97Acquisition Monitor Check and Viewing Conditions................................................................... 97

Test Form 5.1 Detector Uniformity and Artifact Detection.........................................99Detector uniformity..................................................................................................................... 99Results from ROI statistics ...................................................................................................... 100Clinically Relevant Artifacts ..................................................................................................... 100

Contents


Test Form 5.2 Collimation, Dead Space and Compression Paddle Position .......... 101Collimator Assessment ............................................................................................................ 101Compression Paddle Overlap on Chest Wall Side .................................................................. 105Chest Wall Missed Tissue ....................................................................................................... 106

Test Form 5.3 AEC Thickness Tracking Test ......................................................... 107

Test Form 5.4 Spatial Resolution............................................................................ 109Spatial Resolution.................................................................................................................... 109

Test Form 5.5 SNR, CNR and AEC repeatability.................................................... 111AEC Image Stability and Reproducibility and Signal-to-Noise Ratio (SNR) ............................ 111

Test Form 5.6 Image Quality and Radiation Dose .................................................. 113Phantom image quality ............................................................................................................ 113Mean Glandular Dose.............................................................................................................. 114HVL Values from Test Form 5.7 HVL and Radiation Output .................................................. 114Compression release............................................................................................................... 114Compression thickness ........................................................................................................... 114

Test Form 5.7 HVL and Radiation Output............................................................... 117Beam Quality (HVL)................................................................................................................. 117Calculated HVL Values............................................................................................................ 118Radiation Output...................................................................................................................... 118

Test Form 5.8 Tube Voltage Measurement & Reproducibility ................................ 119Tube voltage and reproducibility.............................................................................................. 119

Test Form 5.9 Printer Check ................................................................................... 121Printer Check........................................................................................................................... 121

Test Form 6.1 Ghost Image Evaluation .................................................................. 125Ghost Image Evaluation .......................................................................................................... 126

Contents


Tables


List of Tables

Table 1 Frequency of QC Tests - Technologist ..................................................... 17Table 2 Frequency of QC Tests - Medical Physicist .............................................. 18Table 3 Object Score Criteria for the accreditation phantom Test ......................... 26Table 4 Object Score Criteria for the accreditation phantom Test ......................... 62Table 5 HVL action limits for the different Anode/Filter combinations ................... 65

Tables


Figures


List of Figures

Figure 1 Patient Registration Icon........................................................................... 22

Figure 2 Positioning of the accreditation phantom .................................................. 23

Figure 3 Service Patient.......................................................................................... 24

Figure 4 Potentially Visible Objects in the accreditation phantom .......................... 25

Figure 5 Calibration image ...................................................................................... 28

Figure 6 Accept/Reject Calibration Images............................................................. 29

Figure 7 Patient Registration Window..................................................................... 31


Figure 9 CNR Measurement ................................................................................... 33

Figure 10 Discarded images ..................................................................................... 35

Figure 11 Stand display ............................................................................................ 37

Figure 12 Error Indication Lamp Symbol................................................................... 40

Figure 13 Manual compression................................................................................. 41

Figure 14 Light Field Luminance Measurement........................................................ 42

Figure 15 Location of Squares .................................................................................. 43

Figure 16 Location of Contrast Bar Patterns............................................................. 44

Figure 17 Pixel Test Areas on the Detector .............................................................. 46

Figure 18 ROI Statistics ............................................................................................ 46

Figure 19 Placing the Coin........................................................................................ 49

Figure 20 Placing the Coins ...................................................................................... 50

Figure 21 Positioning the PMMA (seen from above) ................................................ 52

Figure 22 Placing the Resolution Phantom............................................................... 55

Figure 23 Selection of an AEC Sensor ..................................................................... 57


Figure 25 Potentially Visible Objects in the accreditation phantom .......................... 60

Figure 26 Image Attributes........................................................................................ 64

Figure 27 Ghosting 180 sec measurement. .............................................................. 71

Figures


Abbreviations


List of Common Abbreviations

AEC Automatic Exposure Control

AEC D Button AEC Detail Mode Button

AEC H Button AEC Low Dose Button

AWS Acquisition Work Station

CFR Code of Federal Regulations

CNR Contrast-to-Noise Ratio

CSE Customer Service Engineer

FD Flat Detector

FFDM Full Field Digital Mammography

HVL Half Value Layer

kVp Kilovolt Peak

mAs milli Ampere seconds

MEE Mammography Equipment Evaluation

Mo/Mo Molybdenum/Molybdenum

Mo/Rh Molybdenum/Rhodium

MP Medical Physicist

PMMA Poly Methyl Methacrylate

QC Quality Control

ROI Region of Interest

SID Source Image Distance

SMPTE Society of Motion Picture and Television Engineers

SNR Signal-to-Noise Ratio

SOD Source Object Distance

SP Special Systems

T Technologist

W/Rh Tungsten/Rhodium

Abbreviations


For notes

IntroductionMammography Equipment Evaluation (MEE) - Medical Physicist (MP)


1. Introduction

1.1 Mammography Equipment Evaluation (MEE) - Medical Physicist (MP)The MEE tests of the MAMMOMAT NovationDR must be performed whenever a new MAMMOMAT NovationDR system has been installed, reassembled, and whenever changes that might affect performance have been made to an existing system. For example, the MEE tests shall be performed if the system has been disassembled and reassembled or if major components have been changed or repaired.

The MEE tests of the MAMMOMAT NovationDR involve performance of all relevant QC procedures in this Quality Control Manual, ensuring that a basic minimum image quality criteria is met before the system is used on patients. For each part of the MEE tests, action levels that must be met are specified. Furthermore, the values obtained during the MEE tests are to be used as baseline values, and then referred to during future tests to determine if equipment performance is stable or changing.

In facilities under US jurisdiction, the MEE tests must be performed by a qualified medical physicist who meets the final regulation requirements of CFR 900.12(a)(3).

1.2 Annually or Every Six Months - Medical Physicist (MP)For facilities under US jurisdiction, these tests shall be performed at least yearly by a qualified medical physicist as part of the annual physics survey of the mammography unit. Elsewhere, some of them may be performed by a technologist. The tests include comparisons to values measured during the MEE tests to ensure that performance has not degraded.

1.3 Daily - Technologist (T)The purpose of the daily test(s) is to ensure proper and safe performance of the MAMMOMAT NovationDR system. Daily test(s) shall be performed each day before any clinical images are taken.

1.4 Weekly - Technologist (T)These test(s) shall be done on a weekly basis. Weekly test(s) shall be done approximately the same day of the week before patients are examined with the MAMMOMAT NovationDR system.

1.5 Technologist (T)These tests shall be done whenever is suspicion of artifacts or incorrect settings to determine if patients can be examined.

IntroductionSoft Copy Viewing Station


1.6 Soft Copy Viewing StationWhen using a soft copy viewing station, a QC program must be implemented. This program should be substantially equivalent to the program recommended by the manufacturer of the imaging system or the review workstation if they are not the same.

* * The Siemens syngo MammoReport Quality Manual is supplied with the purchase of the syngo MammoReport.

1.7 Laser Camera/PrinterWhen using a laser camera/printer to print mammographic or accreditation images, the printer manufacturer's QC procedure must be followed.

IntroductionFrequency of Required Tests - Technologist


1.8 Frequency of Required Tests - TechnologistTable 1 describes when the tests must be performed by the Technologist.

Table 1 Frequency of QC Tests - Technologist

NOTE!NOTE!If there is a softy copy diagnostic workstation, a QC program must be implemented. Follow the manufacturers recommended procedures or any other substantially equivalent soft copy QC program.

Test Frequency

3.1 Phantom Image Quality Daily

3.2 Detector Calibration As Needed Weekly

3.3. Artifact Evaluation As Needed Weekly

3.4 SNR and CNR Measurements Weekly

3.5 Repeat Analysis Quarterly

3.6 Compression Force Semi-Annually

3.7 Printer Check When required*

* Printer QA is required on days when clinical mammograms or accreditation images are to be printed.

IntroductionRecommended Frequency of QC Tests - Medical Physicist


1.9 Recommended Frequency of QC Tests - Medical PhysicistTable 2 describes when the tests must be performed by the medical physicist.

Table 2 Frequency of QC Tests - Medical Physicist

Test Frequency

Required Tests

4.1 Site Audit / Evaluation of Technologist QC Program

MEE, Annually

4.2 Mechanical Checks MEE, Annually

4.3 Acquisition Workstation Monitor Check MEE, Annually

5.1 Detector Uniformity and artifact Detection MEE, Annually

5.2 Collimation, Dead Space and Compression Paddle Position

MEE, Annually

5.3 AEC Thickness Tracking MEE, Annually

5.4 Spatial Resolution MEE, Annually

5.5 SNR, CNR and AEC Repeatability MEE, Annually

5.6 Image Quality and Radiation Dose MEE, Annually

5.7 HVL and Radiation Output MEE, Annually

5.8 Tube Voltage and Repeatability MEE, Annually

5.9 Printer Check MEE, Annually

Optional Test

6.1 Ghost Image Evaluation MEE, Annually

IntroductionImportant Notes


1.10Important NotesWhile performing quality control test(s), it will be helpful to be familiar with the operating instructions described in the MAMMOMAT NovationDR Operator Manual.

Appendix 1 contains test report tables to be completed to document test parameters used and results obtained during each test.

1.11Required Corrective ActionWhenever there is a result from a test described in this manual that fails to be within the action level stated, the source of the problem must be identified and corrected by a Siemens customer support engineer. Consult with your MP to determine if further testing is required. The system cannot be used on patients until the medical physicist (where applicable) has consented that the test results are acceptable. After the problem has been corrected, a medical physicist or technologist (depending on the test) must conduct the test that failed again to confirm that the problem has been corrected.

IntroductionRequired Equipment - Annual Survey, MEE


1.12Required Equipment - Annual Survey, MEE• Line pair phantom (2-10 lp/mm)

• FDA approved accreditation phantom

• One collimator mounted PMMA (40 mm thick) absorber*

• Three PMMA absorbers, each with a thickness of 20 mm (150x150 mm)

• Lint free non-woven cotton or gauze (100% cotton)

• Water or lukewarm diluted aqueous solution of household dishwashing liquid

• Illuminance meter

• Densitometer

• A non-invasive kV meter

• Dosimeter calibrated at the mammography X-ray beam energies

• Film or CR cassette 24x30 cm or larger

• Compression paddle simulator**

• 2 mm steel plate (FD object table size)*

• 2 mm thick steel bars (approx. 30x100 mm)*

• Pure Aluminum (each 0.10 mm thick) sheets to perform half value layer measurement

• Ruler with a mm scale

* Provided with every system.

**Provided with every system. Testing device allows exposures to be performedwithout compression paddle attached. Detach compression paddle and insert metal plug compression paddle simulator. Radiation field 24x29 cm.

Start Up and LoginProcedure


2. Start Up and Login

2.1 Procedure1. Turn on the MAMMOMAT NovationDR, using the button ( ) on the control panel

to enable the MAMMOMAT. Allow a warm up time of approximately 5 minutes. The internal monitoring system automatically performs a functional check of the MAMMOMAT. "DR" is displayed on the density display on the control panel to indicate that the MAMMOMAT NovationDR system is operational.

2. Switch on the acquisition workstation computer.

CAUTION!If the MAMMOMAT NovationDR has been without power for an extended period of time, the detector will require one hour of warm up. Every second week a message about calibration of the detector is displayed, this is the maximum interval between detector calibrations. Exposures will be locked out unless detector is calibrated every two weeks.

3. Login to the acquisition workstation.

CAUTION!If the MAMMOMAT is started from being completely shut down (for details about complete shut down, see Instructions for Use for (power interrupted at breaker) MAMMOMAT NovationDR) the detector should be powered on at least one hour before intended use. Otherwise, image quality can be affected.

Required Tests - TechnologistPhantom Image Quality


3. Required Tests - Technologist

3.1 Phantom Image Quality

3.1.1 ObjectiveTo ensure that adequate image quality is achieved.

3.1.2 Required Equipmenta) Accreditation phantom

b) Compression paddle 24x30

3.1.3 Procedure1. Login according to the section 2. Start Up and Login.

2. Enter a new patient by pressing Patient Registration icon, see Figure 1, Position 1.

Figure 1 Patient Registration Icon



3. Create a new patient record in the local database, see Figure 7.Fill in: Last Name: Test_One

First Name: Phantom ImagePatient ID: day+time when the test is performed

(example: 200411281350)DOB: 05 05 1955Gender: Other

4. Press Exam button.

5. Choose procedure FD QC processed, see Figure 3, Position 1.

6. Position the accreditation phantom on the breast support, see Figure 2.

Figure 2 Positioning of the accreditation phantom

NOTE!NOTE!Make sure there is no gap between phantom and chest wall.

7. Install the compression paddle.

8. Select the clinically used setting by selecting Opdose program 2 on the control console. AEC sensor 2 shall be selected at the AWS.



9. Double click on the first image in the icon gallery, see Figure 3, Position 2.

Figure 3 Service Patient

10. Make an exposure.

11. Examine the image at acquisition size (full resolution) and optimize window level settings. Determine how many fibers, specks and masses can be visualized. Always count the number of visible objects from the largest object of a given type downward. Note the results in Appendix 1, Test Form 3.1 Phantom Image Quality.

12. If a problem exists while looking at the image on the AWS send the image to the diagnostic review station or printer and then examine the image.

13. Choose the Close patient tab card and close patient by clicking this button.



Figure 4 Potentially Visible Objects in the accreditation phantom

3.1.4 Analysis• Count each fiber as one point if the full length of the fiber is visible and both

its location and orientation is correct. Count a fiber as 0.5 points if not all but more than half of the fiber is visible and its location and orientation are correct. If a fiber-like artifact appears anywhere in the image but is not in an appropriate location or orientation, deduct the "artifactual" fiber from the last "real" fiber scored if the artifactual fiber is equally or more apparent.

• When studying the specks, it can be useful to take advantage of the zoom and invert function. Each speck group shall be counted as one point. A full speck group is counted if four or more specks are visible in the group in the proper locations. Count a speck group as 0.5 points if two or three specks of the group are visible. If noise or speck-like artifacts are visible in the wrong locations in the phantom image, subtract each speck-like artifact one for one from the last real speck counted.

• Count each mass as one point if a density difference is visible in the correct location and the full mass is visible against the background. Count each mass as 0.5 points if a density difference is visible in the correct location but not the full mass is visible, so that the mass does not have a circular appearance. If there is a mass-like artifact in the wrong location anywhere in the image, deduct the "artifactual" mass from the last "real" mass scored if the artifactual mass is equally or more apparent.

XXX XXX

Fibers

Specks

Masses



3.1.5 Performance Criteria and Corrective ActionThe number (total present: 6 fibers, 5 speck groups and 5 masses) of fibers, speck groups and masses that shall be identifiable are given in the table below.

Table 3 Object Score Criteria for the accreditation phantom Test

If any level is found to be beyond any action level stated, the source of the problem must be identified and the problem corrected by a Siemens customer support engineer. Consult with your MP to determine if further testing is required.

Phantom used Required

Fibers ≥ 5

Accreditation phantom Speck groups ≥ 4

Masses ≥ 4

Required Tests - TechnologistDetector Calibration


3.2 Detector Calibration

3.2.1 ObjectiveTo determine that the system has been correctly calibrated with respect to its gain.

3.2.2 Required Equipmenta) Collimator mounted PMMA phantom (40 mm thick)

b) Compression paddle simulator

3.2.3 ProcedureCalibration of the detector must be done:

• Weekly

• When the room temperature differs by more than ±3 °C (±5.4 F) since the last calibration.

• When the artifact detection test (see section 3.3 Artifact Detection) fails.

NOTE!NOTE!Record the values in the form enclosed in Appendix 1, Test Form 3.2 Detector Calibration.

1. Install the collimator mounted PMMA phantom.

2. Install the compression paddle simulator.

3. Set the exposure parameters 28 kV, 250 mAs on the control console.

4. Set the anode/filter combination that is used in most clinical cases, see section 4.1 Site Audit / Evaluation of Technologist QC Program.

5. Select Patient > Detector Calibration from the top menu bar of the Examination task card.The Service Patient is automatically registered.

6. Click the Gain button.A message window is displayed in which you are prompted to confirm the overwriting of old calibration data.

7. Confirm with Yes.


9. Make an exposure.If the image is a uniformly gray you can use it for the calibration. If the image contains disturbing elements, e.g. lines or spots, it is not suitable for calibration.

NOTE!NOTE!You should reject an image if it exhibits any edge cut-off (sharp white line at the borders) due to collimation or misalignment or if there are any artifacts from debris or obstructions.Rectangular segments in the image are acceptable, see Figure 5.



Figure 5 Calibration image



10. Click Accept if the image is suitable for the calibration, see Figure 6.OrClick Reject if the image is not suitable.In the latter case the calibration image is discarded.

11. Continue making calibration images until you have accepted 8 exposures.The number of accepted and discarded calibration images will be displayed.The detector is re-calibrated on the basis of the calibration image.

Figure 6 Accept/Reject Calibration Images


13. Proceed to section 3.3 Artifact Detection.

Required Tests - TechnologistArtifact Detection


3.3 Artifact Detection

3.3.1 ObjectiveTo determine if the detector is dusty, damaged, or has other artifacts.

3.3.2 Required Equipmenta) Collimator mounted PMMA phantom (40 mm thick)


3.3.3 Procedure1. Login according to the section 2. Start Up and Login, if required.


3. Create a new patient record in the local database, see Figure 7. Fill in: Last Name: Test_Three

First Name: Artifact_DetectPatient ID: day+time when the test is performed



5. Choose procedure FD QC Raw.

6. Mount a compression paddle simulator.

7. Assemble the collimator-mounted PMMA phantom (40 mm).


9. Make an exposure using the anode/filter combination used in calibration and 28 kV, 90 mAs.

10. Look at the image for clinical relevant artifacts by magnifying to full resolution. To get full resolution click top "image" drop down menu" and choose "acquisition size”.If artifacts appear go to step 11.If no artifacts appear the artifact detection test is completed.

11. If the image has white pixels contact Siemens customer service engineer.If the image has no white pixels, go to section 3.2 Detector Calibration.


Required Tests - TechnologistArtifact Detection


3.3.4 Performance Criteria and Corrective ActionNo clinically relevant artifacts shall be seen on the image.


Figure 7 Patient Registration Window

Required Tests - TechnologistSignal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements


3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements

3.4.1 ObjectiveTo assure proper functioning of the solid-state detector by evaluating the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the detector. During the MEE testing the obtained values for SNR and CNR should be used as baseline values for further constancy testing.

3.4.2 Required Equipmenta) Accreditation phantom




3. Create a new patient record in the local database. Fill in: Last Name: Test_Four

First Name: SNR_CNRPatient ID: day+time when the test is performed





7. Center the accreditation phantom left to right on the breast support so that it covers all three AEC sensor regions.




8. Select the clinically used setting by selecting 2 (Opdose) on the control console. AEC sensor 2 shall be selected at the AWS, see Figure 23.



11. Draw an ROI by choosing Tools > Circle, size to fit slightly within large mass, see Figure 9, and record the mean pixel value in Appendix 1, Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements.

Figure 9 CNR Measurement

12. To measure the CNR, repeat the same procedure as in step 11 for the background ROI by moving the circular ROI just to the inside of the mass as shown in Figure 9. Move circle laterally adjacent to large mass. Record the mean pixel value and the standard deviation (background) in Appendix 1, Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements.


Mass ROI

Background ROI



3.4.4 AnalysisSNR should be calculated by using the values in Appendix 1, Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements, (see also Figure 18) and the following formula:

Where the DCoffset has a value of 50.

CNR should be calculated by using the values in Appendix 1, Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements, and the following formula:

Deviation from the baseline value (determined during the mammography equipment evaluation) can be calculated by using the following formula:

3.4.5 Performance Criteria and Corrective ActionThe SNR and CNR must not differ by more than ±15% of the baseline values that the medical physicist determined during the mammography equipment evaluation (MEE) (which is required during installation). SNR must also be equal to or greater than 40.


SNRmeanbackground DCoffset–( )

SDbackground---------------------------------------------------------------------------=

CNRmeanbackground meanmass–( )

SDbackground-------------------------------------------------------------------------------=

DeviationBaseline ActualValue–( )

Baseline------------------------------------------------------------------------- 100×=

Required Tests - TechnologistRepeat Analysis


3.5 Repeat Analysis

3.5.1 ObjectiveTo monitor the causes of repeated patient exposures as part of an effort to correct any problems that might exist.

3.5.2 Procedure1. Login according to the chapter 2. Start Up and Login.

2. Open the Patient Browser and click on the Reject button, see Figure 10 Position 1.

Figure 10 Discarded images

3. View each discarded image from the previous month. Use Appendix 1, Test Form 3.5 Repeat Analysis and sort each image into the listed categories.

4. Repeat the procedure at least every 3 months.

Required Tests - TechnologistRepeat Analysis


3.5.3 Analysis1. Sort the images and sum the amount of discarded images for each category.

2. Determine the total number of repeated exposures for all categories and record in Appendix 1, Test Form 3.5 Repeat Analysis

3. Determine the percentage of discarded images for each category by dividing the number of images in each category by the total number of discarded images.

3.5.4 Performance Criteria and Corrective ActionIf a single cause of repeated exposures is discovered, efforts should be made to correct the problem.

Any corrective actions shall be recorded and the results of these corrective actions shall be assessed.

%of repeats 100Total number images (per category)Total number of discarded images

--------------------------------------------------------------------------------------•=

Required Tests - TechnologistCompression Force


3.6 Compression Force

3.6.1 ObjectiveTo measure the compression force in Opcomp and the full automatic max/min and manual (optional) mode of operation.

3.6.2 Required Equipmenta) Bathroom scale or compression force measurement tool

b) Stiff foam block or towel

3.6.3 Procedure1. Place bathroom scale on breast support with weight indicator window toward you

or use other compression force measurement tool according to manufacturer’s instructions.

2. If bathroom scale is used, place foam block or folded towel between scale and compression paddle.

3. Press compression foot switch until Opcomp light (OC) is lit see Figure 11.

Figure 11 Stand display

4. Press compression foot switch again to measure maximum automated compression force. Record force.

5. Increase manual compression using knobs and column to maximum value. Record force. (optional)

NOTE!NOTE!Compression force readout is kilograms (kg). Convert to pounds multiply by 2.2.Convert to Newtons multiply by 10.

3.6.4 Performance Criteria and Corrective ActionMaximum automated compression must be between 12 and 20 kg (25 - 45 pounds).

F

mm

oOC

FOC

Required Tests - TechnologistPrinter Check


3.7 Printer CheckThis test is only required on days when the printer/laser camera is used to print mammograms or accreditation images.

3.7.1 ObjectiveTo assess the quality of the laser camera.

3.7.2 Required Equipmenta) Calibrated densitometer


2. Choose the service patient in the Patient Browser.

3. Select SMPTE image from group [1] Technical Images in the service image patient. Open it in the Viewing task card by double clicking.

4. Send the image to the mammography laser camera/printer.

5. The printer/laser camera shall be configured to Min Density 20 (corresponding to 0.2 optical density) and Max Density to 350 (corresponding to 3.5 optical density), if applicable.

6. Evaluate the printed SMPTE image by measuring the eleven density values from 0 to 100% with the densitometer and note the measured values in Appendix 1, Test Form 3.7 Printer Check.

NOTE!NOTE!This procedure or the printer/laser camera manufacturer's QC procedure must be followed whenever the printer/laser camera is used to print mammographic images or accreditation images.

3.7.4 Performance Criteria and Corrective ActionThe values for the different optical densities must be within the action limits as stated in Appendix 1, Test Form 3.7 Printer Check or as recommended by the printer/laser camera manufacturer.


For the qualification of the printer you may follow the printer/laser camera manufacturer’s recommendations.

Initial Checks - PhysicistSite Audit / Evaluation of Technologist QC Program


4. Initial Checks - Physicist


4.1.1 ObjectiveTo determine the site settings.

To ensure compliance to the Technologist QC tests. Refer to Table 1.

4.1.2 Procedure1. List all compression paddles that will be used routinely in Appendix 2, Test Form


2. Identify the modes chosen for technique selection and note in Appendix 2, Test Form 4.1 Site Audit / Evaluation of Technologist QC Program

3. Define the clinical techniques (used to image accreditation phantom) and note in Appendix 2, Test Form 4.1 Site Audit / Evaluation of Technologist QC Program

4. Determine if other target/filter combinations are used clinically and note in Appendix 2, Test Form 4.1 Site Audit / Evaluation of Technologist QC Program.

5. Make sure that the compliance to the technologist QC tests refered in Table 1 is met.

Initial Checks - PhysicistMechanical Inspection


4.2 Mechanical Inspection

4.2.1 ObjectiveAcceptance MEE:

As deemed appropriate by Medical Physicist to ensure system performance.

Annually:

• To ensure the mechanical integrity of the unit and cables do not show any mechanical damage.

4.2.2 Procedure1. Wipe the breast support and compression paddle with a wet lint free non-woven

cotton cloth or cotton (100%) pad. For moistening, use water or lukewarm diluted aqueous solution of household dishwashing liquid. (No visual damages should be observed. No artifacts should be seen on the calibration images.)

NOTE!NOTE!Do not spray the unit! The cleaning fluid must under no circumstances penetrate into the unit.

2. Check that the cables are free from visual damages. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

3. Check that the control panel lights up to show that the power is switched on. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

4. Turn the swivel-arm system 180° so that the tube head is upside down. Lower the system as close to the floor as possible. Check that the error indication lamp on the generator console (see Figure 12) is lit. Raise and turn the swivel-arm system back again and check that the lamp goes out. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

Figure 12 Error Indication Lamp Symbol



5. Check the motorized movements for smooth running and normal function. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

6. Check that the height adjustment and rotation of the swivel-arm system are blocked, when the displayed compression force is ≥ 3 kg (7 lbs). Note the outcome in Appendix 1, Test Form 4.2 Mechanical Inspection.

7. Check the self-braking of the compression motor. Run the compression paddle against the FD object table, until the applied compression force reaches 15 kg (33 lbs). After 1/2 minute in this condition, this value must not change by more than 2 kg (4 lbs). Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

8. Check that the manual compression/decompression functions properly. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

9. Check that the decompression button on the control console functions correctly. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

Figure 13 Manual compression

10. For power driven compression, the compression device must apply a force with a maximum value between 111 N (approx. 12 kg, 11 on the display of the stand) and 200 N (approx 20 kg, 20 on the display of the stand). Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

MA

M00

664

Maximum compression force presetting knob

Knobs for manual compression/decompression



11. There should be no sharp edges or cracks that could create sharp edges on the compression paddles, detector, etc. which may injure the patient. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

12. All foot switches should operate correctly. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

13. All attachments should latch securely and their locks should function effectively. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

14. Use a luminance meter to measure the light intensity from the X-ray field on the object table in the four areas described in Figure 14. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

Figure 14 Light Field Luminance Measurement

15. The location of the exposure control should confine the operator to the protected area during exposure. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

16. Check the emergency stop button for proper function. Note that with the button depressed, all motorized movements shall be blocked. Note the outcome in Appendix 2, Test Form 4.2 Mechanical Inspection.

Light field

1 2

34

Initial Checks - PhysicistAcquisition Workstation Monitor Check


4.3 Acquisition Workstation Monitor Check

4.3.1 ObjectiveTo assess the quality of the acquisition workstation monitor.

4.3.2 Required Equipmenta) SMPTE test pattern

4.3.3 Procedure1. Clean the monitor

a) The monitor surface should be cleaned with a soft tissue material, such as cotton or lens cleaning paper.

b) If necessary, stubborn stains can be removed by moistening part of a cloth with water to enhance its cleaning power.

3. Select the Viewing task card on the right edge of the monitor.

4. Select the Service images in the local data base in the Patient Browser.

5. Open the image labeled “Group [1] Technical Images”. Double click on the image for display. Make sure that the SMPTE is covering the entire viewing area i.e. the window should not be divided in four viewing areas.Check that the window width is set to 4096 and that the window center is set to 2048. Display image in acquisition size under Image > Acquisition Size. Erase text using View > No Text.

6. The gray scale is shown as a series of squares in the central part of the SMPTE image, ranging from black (0%) to white (100%). The 0% and 100% squares each contain smaller squares within them that represent signal level steps of 5% and 95% respectively (see Figure 15). You should be able to differentiate the inner square from the larger square that contains it. The 5% square is normally quite difficult to differentiate. If this is not possible then perform this test again with dimmed room light.

Figure 15 Location of Squares

95 %5 %

Initial Checks - PhysicistAcquisition Workstation Monitor Check


7. Visually check the monitor’s performance by looking for streaking, fluttering and shadows.

8. The spatial resolution (linearity) and aliasing (distortion) of the monitor are considered to be within acceptable limits if the high contrast bar patterns in the test image can be seen as patterns of white and black pairs. To use the pattern, inspect all six of the high contrast patterns in each corner (see Figure 16) of the images as well as in the center. You should be able to differentiate all the lines in all the high contrast patterns.

Figure 16 Location of Contrast Bar Patterns


4.3.4 Performance Criteria and Corrective Action• The 5% and 95% squares must be visible.

• All high contrast bar patterns in the four corners and in the center of the image (see Figure 16) shall be resolved.


Required Tests - PhysicistDetector Uniformity and Artifact Detection


5. Required Tests - Physicist

5.1 Detector Uniformity and Artifact Detection

5.1.1 ObjectiveTo measure the uniformity of the detector response over its entire surface and to determine if the detector is dusty, damaged, or has other artifacts.

5.1.2 Required Equipmenta) Collimator mounted plexi (40 mm)




3. Create a new patient record in the local database. Fill in: Last Name: Test_One

First Name: Detector UniformityPatient ID: day+time when the test is performed




6. Install the collimator-mounted plexi (40 mm).

7. Install the compression paddle. Set at height of 4.5 cm.


9. Make an exposure with 28 kV, AEC mode H and the anode/filter combination that the system has been calibrated with, see section 4.1 Site Audit / Evaluation of Technologist QC Program.

10. Check that there are no defective columns and no grid lines in the image. Optimize window and center (start with W = 500 and C = 600).

11. Choose Postprocessing sub tab card.

12. Choose rectangular ROI Tool.



13. Make an ROI (Region Of Interest) by choosing Tools > Rectangle with the size of the ROI approximately 10x10 mm according to Figure 17 and located appro. 20 mm of the edges as shown in Figure 17. (Annotation can be removed by clicking on View > No Text.)

Figure 17 Pixel Test Areas on the Detector

14. ROI Statistics will be shown. see Figure 18.Record the mean value in the selected area in Appendix 2, Test Form 5.1 Detector Uniformity and Artifact Detection.

Figure 18 ROI Statistics

15. Move the ROI four times until you have measured all five areas shown in Figure 17.

Mean Value



16. Look at the image for clinical relevant artifacts by magnifying to full resolution.To get full resolution click top "image" drop down menu and choose "acquisition size”. Activate zoom/pan under image menu. Image may be panned when cursor is displayed as crossed arrows.If artifacts appear go to step 17.If no artifacts appear go to step 18.

17. If the image has white pixels go to step 19.If the image has no white pixels, make a calibration, see section 3.2 Detector Calibration. If artifacts still appear, call Siemens customer service engineer otherwise go to step 12.

18. If no artifacts can be detected, continue with the examinations.

19. For pixel correction, please call Siemens customer service engineer.


5.1.4 Performance Criteria and Corrective ActionThe required performance criteria: The mean pixel value inside each of the five ROI locations shall not differ by more than 10% from the mean value of the means.

The desired performance criteria: The mean pixel value inside each of the five ROI locations shall not differ by more than 5% from the mean value of the means.

No clinically relevant artifact shall be seen in the image.

If any level is found to be beyond any action level stated, the source of the problem must be identified and the problem corrected by a Siemens customer support engineer. Consult with your MP to determine if further testing is required

Required Tests - PhysicistCollimation, Dead Space and Compression Paddle Position


5.2 Collimation, Dead Space and Compression Paddle Position

5.2.1 Objective• To ensure that the collimator does not allow significant radiation beyond the

edges of the image detector.

• To ensure that the chest wall missed tissues are within the tolerance of 5 mm maximum.

• To ensure that the position of the chest wall side of each standard compression paddle allows for complete imaging of the chest wall tissues.

5.2.2 Required Equipmenta) Seven identical coins

b) Ruler

c) 24x30 Compression paddle, 20x22 (coned) Compression Paddle

d) Film or CR cassette (24x30 or larger)



3. Create a new patient record in the local database. Fill in: Last Name: Test_Two

First Name: Chest Wall Missed TissuePatient ID: day+time when the test is performed


4. Press Exam button see Figure 7.

5. Choose procedure FD QC Raw, see Figure 3, Position 1.

6. Install the 24 x 30 Compression paddle.



7. Place the X-ray Tube in 0° position.

Figure 19 Placing the Coin

8. Tape the coin (3) on the breast support so that its edge is exactly tangent to the chest wall edge of the FD object table. See Figure 19.

9. Tape a coin on the lower surface of the 24x30 compression paddle tangent to the chest wall edge.

10. Place a film or CR cassette 24x30 or larger on top of the FD object table and turn it so the mid points of each edge of the light field are within the film in the cassette, see Figure 20.

11. Install the compression paddle and set the compression paddle position about 4-5 cm above the breast support. Wait until collimation according to paddle size is done and remove paddle.

12. Turn on the light field.

13. Place 4 coins (1, 2, 4, 6) on the film cassette as markers on the mid point of each light field edge so that the edges of the coins are tangent to the outer light field edges. Place coin (7) on the film cassette, see Figure 20.

14. Install the compression paddle 24 x 30



Figure 20 Placing the Coins


16. Using a film cassette make an exposure with 28 kV, 50 mAs and using the clinical target/filter combination (see section 4.1 Site Audit / Evaluation of Technologist QC Program). For CR cassettes use appropriate technique.

17. Develop the film in the cassette and mark it with anode/filter combination used.

18. On the acquisition workstation monitor measure the distance e for coin 7, distance x for coin 3 and y for coin 5 and measure the distance g for coin 1, 2, 4, 6 in Figure 20.

Drawing distance linesClick on the Distance button on the Tools sub task card.Draw a line with the left mouse button kept pressed. The distance is displayed immediately while dragging the line.

Also measure the distance f for coin 1, 2, 4 and 6 on the developed film or CR cassette with a ruler, according to Figure 20 and note in Appendix 2, Test Form 5.2 Collimation, Dead Space and Compression Paddle Position.

19. Repeat steps 7- 18 with 28 kV, 50 mAs, using alternative filter/anode combination.

20. Remove all coins.

21. Tape a coin on the lower surface of the 20x22 compression paddle tangent to the chest wall edge (coin 5). Place coin 7 on to the detector.



22. Install the compression paddle and set the compression paddle position about 4-5 cm above the breast support.

23. Make an exposure with 25 kV, 20 mAs, and using the clinical target/filter combination (see section 4.1 Site Audit / Evaluation of Technologist QC Program).

24. On the acquisition workstation monitor measure the distance e and y for the coin and note in Appendix 2, Test Form 5.2 Collimation, Dead Space and Compression Paddle Position.

25. Repeat step 22 to 23 with 25 kV, 20 mAs, using alternative filter/anode combination.

26. Repeat step 20 to 24 with all standard compression paddles.


NOTE!NOTE!Do not use Flex paddles for this test.

5.2.4 Performance Criteria and Corrective Action• Detector Dead Space indicated by the missing part of the coin on the Breast

support must be ≤ 5 mm.

• The X-ray/light-field misalignment (sum of misalignments on opposite sides), must not exceed 2% of SID (13 mm).

• The X-ray field must not extend beyond the detector's active area at any one side by more than 2% of SID (13 mm).

• The X-ray field shall cover all of the detector's active area on the chest wall side (e.g., it cannot be inside the detector on the chest wall side).

• The compression paddle must not extend beyond the active detector area at the chest wall by more than 6.5 mm.


Required Tests - PhysicistAEC Thickness Tracking Test


5.3 AEC Thickness Tracking Test

5.3.1 ObjectiveTo assure that the AEC function is tracking by evaluation images acquired with different thicknesses and techniques.

5.3.2 Required Equipmenta) Three PMMA absorbers, 20 mm thick each




3. Create a new patient record in the local database. Fill in: Last Name: Test_Three

First Name: AEC TrackingPatient ID: day+time when the test is performed



5. Choose procedure FD QC Raw. AEC Sensor 1 shall be used, see Figure 23.

6. Put the 20 mm PMMA on the breast support (Figure 21).

Figure 21 Positioning the PMMA (seen from above)


PMMA

Required Tests - PhysicistAEC Thickness Tracking Test


8. Use the anode/filter combination with which the system is calibrated, see section 4.1 Site Audit / Evaluation of Technologist QC Program and AEC mode H for all exposure.

Use the kVp values shown below.2cm - 26 kVp 4cm - 28 kVp 6cm - 32 kVp



11. Click the Postprocessing sub tab card or select an ROI (Region of Interest) by choosing Tools > Rectangle. Set size of ROI approximately 10x10 mm and 60 mm from the chest wall side. Measure the mean pixel value and the standard deviation and fill them in the table in Appendix 2, Test Form 5.3 AEC Thickness Tracking Test

12. Calculate SNR according to the following formula:


13. Repeat the same procedure from step 8 - 13 for all thicknesses and techniques listed in step 8.


15. Calculate the mean value for the mean of the SNR values for the different thicknesses. Fill in the values in the table.

16. Calculate the maximum deviation from the mean value of the pixel value and SNR measurements using the following formula:

Maximum deviation = (Maximum difference / Mean Value) x 100 %

5.3.4 Performance Criteria and Corrective ActionThe minimum SNR must be ≥ 40 and the maximum deviation from the mean value must be ≤ ±15 %.



SDbackground---------------------------------------------------------------------------=

Required Tests - PhysicistSpatial Resolution


5.4 Spatial Resolution

5.4.1 ObjectiveTo ensure that adequate spatial resolution is obtained with the MAMMOMAT NovationDR system.

a) Line pair phantom

b) 40 mm (PMMA) phantom

c) Compression paddle 24x30



3. Create a new patient record in the local database. Fill in: Last Name: Test_Four

First Name: Spatial ResolutionPatient ID: day+time when the test is performed




6. Mount the compression paddle.

7. Select the clinically used setting by selecting Opdose program 3 on the control console. AEC sensor 3 shall be selected at the AWS (sensor 3 shall be covered with the PMMA phantom). Be sure that the resolution phantom doesn’t cover the AEC sensor area, see Figure 23.

Required Tests - PhysicistSpatial Resolution


8. Place the 40 mm PMMA phantom parallel to the chest wall edge. Place the line pair phantom on the phantom with the bars at an angle of approximately 45 degrees (see Figure 22) to the tube axis, about 1 cm from the chest wall and with the largest pattern toward the chest wall.

Figure 22 Placing the Resolution Phantom



11. Examine the image and starting with the largest bars determine the highest line-pair resolution where the bars can be clearly seen. Make a magnification to full resolution of the image using Image > Acquisition size. Optimize window/level. Start at W = 500 and C = 250 (Magnifier window over the patterns may help). Note the outcome in Appendix 2, Test Form 5.4 Spatial Resolution.


5.4.3 Performance Criteria and Corrective ActionThe measured resolution shall be at least 7 lp/mm.


45

AEC 3

Required Tests - PhysicistSNR, CNR and AEC repeatability


5.5 SNR, CNR and AEC repeatability

5.5.1 ObjectiveTo assure proper functioning of the solid-state detector by evaluating the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the detector. During the MEE testing the obtained values for SNR and CNR should be used as baseline values for further constancy testing.

To measure the AEC image stability and the AEC reproducibility.

5.5.2 Required Equipmenta) Dosimeter calibrated at the mammography X-ray beam energies

b) Accreditation phantom




3. Create a new patient record in the local database. Fill in: Last Name: Test_Five

First Name: AECPatient ID: day+time when the test is performed





7. Center the accreditation phantom left to right on the breast support so that it covers all three sensor regions.

8. Place the dosimeter to the side of the phantom and with its center at 40 mm from the chest wall edge of the patient support. Refer to Figure 24. Put the dose meter at the same level as the top surface of the accreditation phantom.

9. Check that the phantom covers all three regions of the AEC sensors by compressing the compression paddle. See Figure 24.



10. Select the clinically used setting by selecting 2 (Opdose) on the control console. AEC sensor 2 shall be selected at the AWS, see Figure 23.

Figure 23 Selection of an AEC Sensor


12. Make an exposure and record the mAs and entrance dose in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability.

13. Repeat steps 11 to 12 until 5 exposures have been made.

14. Select an ROI (Region Of Interest) by choosing Tools > Circle or click on the Postprocessing sub tab card.

15. Set the size of the ROI to be slightly smaller than the largest mass, about 0.4 cm². See Figure 9.

16. Measure the mean pixel value and standard deviation adjacent to the largest mass. See Figure 9 (Try to measure the same area for all images).

17. For image number 5 also measure the contrast to noise value (CNR). Measure the mean pixel value inside the largest mass. Record values in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability.




5.5.4 AnalysisSNR should be calculated by using the values in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability, (see also Figure 18) and the following formula:


CNR should be calculated by using the values in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability, and the following formula:

Calculate the mean value of the mAs, entrance air kerma or exposure, mean pixel value and SNR. Record these values in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability

Calculate the coefficient of variation for the mAs and air kerma/exposure and the maximum deviation from the mean for mean pixel value and SNR.

5.5.5 Performance Criteria and Corrective ActionThe coefficient of variation for the mAs and entrance kerma/exposure must be less than 5%. The maximum deviation of the mean pixel values and SNR measurements must be less than or equal to ±15% of the mean values for the measurements.

NOTE!NOTE!The SNR and CNR values measured by the medical physicist during installation or MEE should be communicated to the QC Technologist and will define the base line values for these measurements.



SDbackground---------------------------------------------------------------------------=

CNRmeanbackground meanmass–( )

SDbackground-------------------------------------------------------------------------------=

Required Tests - PhysicistImage Quality and Radiation Dose


5.6 Image Quality and Radiation Dose

5.6.1 ObjectiveTo ensure that adequate image quality is achieved.

Measure the mean glandular dose to ensure that it does not exceed 3.0 mGy, which is the maximum value allowed in the regulations for screen-film systems as well as for full field digital mammography (FFDM) systems.


b) Accreditation phantom


NOTE!NOTE!HVL Values will be required to calculate Radiation Dose.



3. Create a new patient record in the local database. Fill in: Last Name: Test_Six

First Name: Mean Glandular DosePatient ID: day+time when the test is performed



5. Choose procedure FD QC processed.


7. Center the phantom left to right and place dosimeter next to phantom and about 4 cm from chest wall edge, see Figure 24. Try to get the dosimeter at the same height as the phantom top. Compress phantom until OpComp indicator light is lit, see Figure 11.




8. Choose Opdose 2 on the control console. Select AEC sensor 2 at AWS, see section 4.1 Site Audit / Evaluation of Technologist QC Program.

9. Use H mode.


11. Select the automatic decompression button on the control console.

12. Make an exposure and check if an automatic release of the compression paddle was performed and note in Appendix 2, Test Form 5.6 Image Quality and Radiation Dose.

NOTE!NOTE!Record all values in the appropriate place in section 5.6 Image Quality and Radiation Dose and calculate the mean glandular dose. Other accepted methods for calculating mean glandular dose may also be used.

13. Examine the image at acquisition size (To get full resolution click top “image” -> “acquisition size.) optimize window level settings. Determine how many fibers, specks and masses can be visualized. Always count the number of visible objects from the largest object of a given type downward. Note the results in Appendix 2, Test Form 5.6 Image Quality and Radiation Dose.

Figure 25 Potentially Visible Objects in the accreditation phantom

XXX XXX

Fibers

Specks

Masses



14. If a problem exists while looking at the image on the AWS send the image to the diagnostic reviewstation or printer and then examine the image.

15. Record the thickness reported in the image annotation, see Appendix 2, Image Quality and Radiation Dose.

16. Optional: Repeat radiation dose and image quality tests for D Mode. (Unless D Mode is the clinical Technique).


5.6.4 Analysis• Count each fiber as one point if the full length of the fiber is visible and the

location and orientation of the fiber are correct. Count a fiber as 0.5 point if not all but more than half of the fiber is visible and its location and orientation are correct. If a fiber-like artifact appears anywhere in the image but is not in an appropriate location or orientation, deduct the "artifactual" fiber from the last "real" fiber scored if the artifactual fiber is equally or more apparent.

• When studying the specks, it can be useful to take advantage of the zoom and invert function. Each speck group shall be counted as one point. A full speck group is counted if four or more specks are visible in the group in the proper locations. Count a speck group as 0.5 point if two or three specks of the group are visible. If noise or speck-like artifacts are visible in the wrong locations in the phantom insert, subtract each speck-like artifact one for one from the last real speck counted.

• Count each mass as one point if a density difference is visible in the correct location and the full mass is visible against the background. Count each mass as 0.5 point if a density difference is visible in the correct location but the full mass is not visible, so that the mass does not have a circular appearance. If there is a mass-like artifact in the wrong location anywhere in the image, deduct the "artifactual" mass from the last "real" mass scored if the artifactual mass is equally or more apparent.



5.6.5 Performance Criteria and Corrective ActionThe required performance criteria:

• The mean glandular dose must not exceed 3 mGy (3 mRad).

The desired performance criteria:

• The mean glandular dose should not exceed 2 mGy (2mRad).

The number (total present: 6 fibers, 5 speck groups and 5 masses) of fibers, speck groups and masses that shall be identifiable are given in the table below.

Table 4 Object Score Criteria for the accreditation phantom Test


Phantom used Required

Fibers ≥ 5

Accreditation phantom Speck groups ≥ 4

Masses ≥ 4

Required Tests - PhysicistHVL and Radiation Output


5.7 HVL and Radiation Output

5.7.1 ObjectiveCalculate the half value layer (HVL) from measured exposure data. The HVL value ob-tained is subsequently used in the Dose Calculation.

To measure the radiation output of the system when operating at 28 kVp in standard mammography mode.


b) 2 mm steel plate (object table size)

c) Spot compression paddle

d) Sheets of 99.9 % pure aluminium covering thicknesses from 0.2 to 0.6 mm.



3. Create a new patient record in the local database.Fill in: Last Name: Test_Seven

First Name: HVLPatient ID: day+time when the test is performed




6. Install the spot compression paddle to collimate the X-ray beam.

7. Raise the compression paddle to its highest position and place the 2 mm steel plate on the object table.

NOTE!NOTE!It is important that the 2 mm steel or lead is covering the detector during the entire test.

8. Place the dosimeter on the object table. Make sure the receptive area is fully within the X-ray field, use the light field as a guidance.

9. Set 28 kVp and anode/filter combination see section 4.1 Site Audit / Evaluation of Technologist QC Program (Opdose 2, clinical technique) and set mAs = 50.




11. Make an exposure. Note the dosimeter reading in Appendix 2, Test Form 5.7 HVL and Radiation Output period.

12. For Mo/Mo place 0.3 mm aluminum sheets on top of the compression paddle. For Mo/Rh place 0.4 mm aluminum and for W/Rh place 0.5 mm aluminum on top of the compression paddle. Make sure the Al sheets cover the whole active detector area of the dosimeter.

13. Make another exposure. Record the dosimeter reading and the Al thickness in Appendix 2, Test Form 5.7 HVL and Radiation Output.

14. Place an additional 0.1 Al sheet on top of the compression paddle.

15. Repeat steps 13 to 14 until the dosimeter reading is less than half the first exposure reading that you made without any Al sheets.

16. Remove all Al sheets, make an exposure and record the dosimeter reading. If the value differs more than 2% from the first exposure reading, repeat from step 11.

17. Make one more exposure using 28 kVp 400mAs Mo/Mo. Record the radiation air kerma/exposure and exposure time in Appendix 2, Test Form 5.7 HVL and Radiation Output

18. Note the time of the exposure that is displayed in the Image Attributes ... by clicking on the right mouse button on the image icon.

Figure 26 Image Attributes

19. Calculate the radiation output with the following formula:

radiation output rate = air kerma / time or exposure / time


21. Calculate the HVL values for each anode/filter combination following the formula and note the values in Appendix 2, Test Form 5.7 HVL and Radiation Output.



5.7.4 Calculating HVLFrom the previous measurements, the HVL value can be calculated. The formula to use is:

where

D0 = air kerma/exposure reading without aluminum

Da = air kerma/exposure reading just greater than half of D0

Db = air kerma/exposure reading just less than half of D0

ta = aluminum layer thickness corresponding to Da

tb = aluminum layer thickness corresponding to Db

ln is short for the natural logarithm

5.7.5 Performance Criteria and Corrective ActionThe radiation output rate must be higher than 7.0 mGy air kerma per second, alternatively 800 mR per second.

Table 5 HVL action limits for the different Anode/Filter combinations

The HVL for all anode filter combinations must be greater or equal to kVp/100.


Anode/Filter HVL value at 28kVp(kVp/100)

Mo/Mo ≥ 0.28

Mo/Rh ≥ 0.28

W/Rh ≥ 0.28

HVLtb 2Da D0⁄[ ]ln⋅( ) ta 2Db D0⁄[ ]ln⋅( )–

Da Db⁄[ ]ln----------------------------------------------------------------------------------------=

Required Tests - PhysicistTube Voltage Measurement & Reproducibility


5.8 Tube Voltage Measurement & Reproducibility

5.8.1 ObjectiveTo verify that the accuracy of the tube voltage value displayed is in accordance with the specifications.

5.8.2 Required Equipmenta) Non-invasive kVp meter calibrated in the mammography range.


c) 2 mm steel plate



3. Create a new patient record in the local database.Fill in: Last Name: Test_Eight

First Name: Tube VoltagePatient ID: day+time when the test is performed




6. Make sure that the Mammomat system has been powered on for at least 15 minutes.

7. Install the compression paddle simulator.

8. Place the 2 mm steel plate on the detector.

9. Place the detector part of the digital kVp meter on top of the steel plate. Care should be taken to position the detector in accordance with the manufacturer's recommendations. (Alternative procedure: place kVp meter on top of compression paddle. Center active area in the beam.)




11. Make 4 exposures at the clinical kVp (see section 4.1 Site Audit / Evaluation of Technologist QC Program) using 50 mAs and Mo/Mo.For each measurement, record the tube voltage value kVp from the kV meter in Appendix 2, Test Form 5.8 Tube Voltage Measurement & Reproducibility.

12. For each of the following kVp's one exposure is required:26kVp, 28kVp, 30kVp, 32kVp and 34kVp (50 mAs, Mo/Mo).For each measurement, record the tube voltage value kVp from the kV meter in Appendix 2, Test Form 5.8 Tube Voltage Measurement & Reproducibility.


5.8.4 CalculationsThese calculations can be easily performed with an inexpensive calculator.

1. Formula for Accuracy (expressed in percent):

kVpmeas = Measured kVpkVpset = The set value of the tube voltage

2. Coefficient of variations Cv (expressed in percent):

Mean value for the tube voltage measurement:

kVpi = The sampled measurementn = The number of measurements sampled (n here = 4)

kVpmeas kVpset–

kVpset---------------------------------------------- 100×

Cv1

kVpmean------------------------

kVpi kVpmean–( )2

n 1–--------------------------------------------------

i 1=

n

∑

12---

100×=

kVp1 kVp2 kVp3 kVp4+ + +

4------------------------------------------------------------------------kVpmean =



Example: Calculating the kVp reproducibility coefficient of variations Cv:

a) Settings: kVpset = 27kVp, 50mAs and Mo/MoRecord the four consecutive measurements and calculate the mean value kVpmean in Appendix 2, Test Form 5.8 Tube Voltage Measurement & Reproducibility.

b) Subtract each individual measurement sample from the mean value kVpmean and square each difference.

c) Sum up the 4 squared differences and divide the sum by 3.The summed difference divided by 3 is: 0.05/3=0.0167

d) Take the square root of the result and divide by the mean value kVpmean and multiply by 100 to get the result in percent.

5.8.5 Performance Criteria and Corrective ActionAccuracy: The measured tube voltage kVp shall be accurate to within ±5%

of the selected kVp

Reproducibility: The coefficient of variation of the kVp reproducibility shall be equal to or less than 2%.


Measurement no kVp1 kVp2 kVp3 kVp4

Tube voltage [kV] 27.2 27.1 27.0 27.3

kVpmean (kVp1+kVp2+kVp3+kVp4)/4=27.15

Difference 0.05 -0.05 -0.15 0.15

Difference squared 0.0025 0.0025 0.0225 0.0225

%5.0%476.010015.27

0167.0 2

1

≈=∗ The result is within the specified design criteria.

Required Tests - PhysicistPrinter Check


5.9 Printer CheckThis test is only required on days when the printer/laser camera is used to print mammograms or accreditation images.

5.9.1 ObjectiveTo assess the quality of the laser camera.

5.9.2 Required Equipmenta) Calibrated densitometer


2. Choose the service patient in the Patient Browser.

3. Select SMPTE image from group [1] Technical Images in the service image patient. Open it in the Viewing task card by double clicking.

4. Send the image to the mammography laser camera/printer.

5. The printer/laser camera shall be configured to Min Density 20 (corresponding to 0.2 optical density) and Max Density to 350 (corresponding to 3.5 optical density), if applicable.

6. Evaluate the printed SMPTE image by measuring the eleven density values from 0 to 100% with the densitometer and note the measured values in Appendix 2, Test Form 5.9 Printer Check.

NOTE!NOTE!This procedure or the printer/laser camera manufacturer's QC procedure must be followed whenever the printer/laser camera is used to print mammographic images or accreditation images.

5.9.4 Performance Criteria and Corrective ActionThe values for the different optical densities must be within the action limits as stated in Appendix 2, Test Form 5.9 Printer Check or as recommended by the printer/laser camera manufacturer.


For the qualification of the printer you may follow the printer/laser camera manufacturer’s recommendations.

Optional TestGhost Image Evaluation


6. Optional Test

6.1 Ghost Image Evaluation

6.1.1 ObjectiveGhosting could be described as "shadows" of the previous exposure.

The ghost image caused by a 2600 mR exposure will decay to less than 3% in a subsequent 8 mR exposure after 180 sec. Contrast is defined as the difference between the digital pixel value measured within the ghost image and outside the ghost image relative to the average pixel value inside and outside the ghost image. The digital pixel value will be the average of pixel values inside a square of 10x10 mm.

The objective of this test is to ensure that the ghosting is within an acceptable level.

6.1.2 Required Equipmenta) 2 mm steel plate (breast support)

b) 2 mm small steel bars (approx. 30x100 mm)

c) 40 mm PMMA phantom (collimator mounted)

d) Compression paddle simulator

e) 4 paper clips

f) Timer

6.1.3 Pre RequisitesA gain calibration shall recently have been done but the detector shall not have been exposed on within 30 minutes.



3. Create a new patient record in the local database. Fill in: Last Name: Test_One

First Name: GhostingPatient ID: day+time when the test is performed




6. Cover the FD object table with the 2 mm steel.



7. Install a compression paddle simulator.


9. Make the first exposure using 23 kV, 2 mAs and Mo/Mo.

10. Remove the 2 mm steel plate and place the 2 mm steel bar on the FD object table, see Figure 27 second exposure. Place also the paper clips to point out the corners of the steel bar.

11. Make a second exposure using 28 kV, 200 mAs and Mo/Mo. Start the timer when pressing the exposure buttons.

12. Remove the steel bar without moving the paper clips and place the 40 mm collimator mounted plexi.

13. After approximately 180 seconds make a third exposure using 28 kV, 14 mAs and Mo/Mo.

14. Measure the offset in the first image. Select an ROI (Region of Interest) by choosing Tools > Circle, size approximately 10 x10 mm, in the center of the image, 20 mm from the chest wall side. Measure the mean value of a region at the PMMA and note the value in Appendix 2, Test Form 6.1 Ghost Image Evaluation.

Figure 27 Ghosting 180 sec measurement.PV1 is the mean from the ROI within the former position of the steel bar.i.e. PV2 is the mean from the ROI outside the former position of the steel bar.

Position 3Position 2

Position 4Position 1Third exposure after 180 secondsSecond exposure

Steel bar

Paper clip



15. Measure the mean values PV1 and PV2 by using the paper clips as a guidance if the ghost image is not visible as shown in Figure 27 third exposure. Select an ROI (Region of Interest) by choosing Tools > Circle size approximately 10x10 mm. Measure the mean value of a region at the plexi and note the value in Appendix 2, Test Form 6.1 Ghost Image Evaluation.

NOTE!NOTE!PV1 and PV2 are the compensated mean pixel values,PVi Mean = Pixel value i - Offset Value (Offset Value is 50).

16. Repeat step 15 until all regions has been measured.


18. Calculate the ghosting in percent [%] according to:

6.1.5 Performance Criteria and Corrective ActionThe ghosting figure of merit as defined in step above must be less than 3%.


Ghosting 200 PV1 PV2–( )PV1 PV2+

-----------------------------------⋅=

Appendix 1 to MAMMOMAT NovationDR QC Manual


7. Appendix 1 – QC Forms Technologist Tests



For notes



Test Form 3.1 Phantom Image Quality

NOTE!NOTE!Record the measured values on a copy of Appendix 1 pages and file it along with the QC-manual.

Phantom image quality

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter: Performancecriteria (RMI 156)

Passed Failed

kV:

mAs:

Fibers ≥ 5 l lSpeck Groups

≥ 4 l lMasses ≥ 4 l l

Comments: _______________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________



For notes



Test Form 3.2 Detector CalibrationNOTE!NOTE!

Record the measured values on a copy of Appendix 1 pages and file it along with the QC-manual.

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Year

Month

Day

Time

Temperature

Performed by

Year

Month

Day

Time

Temperature

Performed by

Year

Month

Day

Time

Temperature

Performed by



Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

Review: ____________________________________ Date: ______________________________________



Test Form 3.3 Artifact Detection


Clinically Relevant Artifacts

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter combination Passed Failed

l l

l l

l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



For notes



Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements


Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



Signal-to-Noise Ratio and Contrast-To-Noise Ratio Measurements

MeanBack-ground

MeanMass

SD Dev.Back-ground

SNR CNR DeviationSNR

DeviationCNR

Performancecriteria

Passed Failed

Baseline

1st SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

2nd SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

3rd SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

4th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

5th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

6th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

7th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

8th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

9th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

10th SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 3.5 Repeat Analysis

Printer manufacturer's QC procedure must be followed whenever the printer is used to print mammographic images or accreditation images.


Mammography Repeat Analysis

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

From ________________________ to ________________________

Categories Projection Repeated (mark one for each repeated image)

Number of dis-carded images/ repeated images

% of dis-

carded images

Left CC

Right CC

Left MLO

Right MLO

Left Other

Right Other

1. Image artifact(s)

2. Grid artifact(s)

3. Positioning

4. Monitor blur

5. Under exposed

6 Over exposed

7. No image

8. Detector artifact(s)



9. Artifact(s) other than grid or detector

10. Mechanical failure

11. Electrical failure

12. Software failure

13. Inappropriate image processing

14. Other failure

15. Unknown failure

16. Double exposure

Total num-ber of dis-

carded images/repeated images

Yes No

Corrective actions l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

Corrective actions: _________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 3.6 Compression Force


Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Value Performance Criteria

Passed Failed

Force Opcomp

Maximum Force Automatic

Force between 12 and 20 kg

l lMaximum Force Manually (optional)

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



For notes



Test Form 3.7 Printer Check


NOTE!NOTE!Record the measured values on a copy of Appendix 1 pages and file it along with the QC-manual. Your physicist can help with this test at system installation.

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



Printer Check

* LUT = Look-Up-Table

Customer values for Min and Max Density

Min Density

Max Density

Step Corr16b-bspline (LUT) Linear LUT

Ref. LUT Maximum density

Minimum density

Ref. LUT Maximum density

Minimum density

1 0.20 0.23 0.17 0.20 0.23 0.17

2 0.34 0.38 0.30 0.52 0.56 0.49

3 0.47 0.51 0.43 0.86 0.90 0.82

4 0.64 0.69 0.59 1.18 1.23 1.13

5 0.81 0.87 0.75 1.52 1.58 1.46

6 1.05 1.12 0.99 1.84 1.91 1.78

7 1.31 1.38 1.24 2.18 2.25 2.11

8 1.66 1.74 1.58 2.52 2.60 2.44

9 2.10 2.19 2.01 2.85 2.94 2.77

10 2.68 2.77 2.59 3.18 3.27 3.08

11 3.50 3.60 3.40 3.50 3.60 3.40

Step MG1_5bCorr-bspline (LUT)

Ref. LUT Maximumdensity

Minimumdensity

1 0.20 0.23 0.17

2 0.44 0.48 0.40

3 0.68 0.72 0.64

4 0.94 0.99 0.89

5 1.18 1.24 1.12

6 1.45 1.52 1.39

7 1.73 1.80 1.66

8 2.01 2.09 1.93

9 2.32 2.41 2.23

10 2.73 2.82 2.64

11 3.50 3.60 3.40




Step Corr16b-bspline (LUT)

Ref. LUT*

Recommenda-tion Maximum

density

Recommenda-tion Minimum

density

Required Maximum density

RequiredMinimum density

1 0.20 0.23 0.17 0.30 0.10

2 0.34 0.38 0.30 0.44 0.24

3 0.47 0.51 0.43 0.57 037

4 0.64 0.69 0.59 0.74 0.54

5 0.81 0.87 0.75 0.91 0.71

6 1.05 1.12 0.99 1.15 0.95

7 1.31 1.38 1.24 1.41 1.21

8 1.66 1.74 1.58 1.76 1.56

9 2.10 2.19 2.01 2.20 2.00

10 2.68 2.77 2.59 2.78 2.58

11 3.50 3.60 3.40 3.60 3.40


Ref. LUT Recommenda-tion Maximum

density


density

Required Maximumdensity

Required Minimumdensity

1 0.20 0.23 0.17 0.30 0.10

2 0.44 0.48 0.40 0.54 0.34

3 0.68 0.72 0.64 0.68 0.58

4 0.94 0.99 0.89 1.04 0.84

5 1.18 1.24 1.12 1.28 1.08

6 1.45 1.52 1.39 1.55 1.35

7 1.73 1.80 1.66 1.83 1.53

8 2.01 2.09 1.93 2.11 1.91

9 2.32 2.41 2.23 2.42 2.22

10 2.73 2.82 2.64 2.83 2.63

11 3.50 3.60 3.40 3.60 3.40



If your values do not meet the values specified above, then please refer to the printer manufacturer's quality control procedure. You can create your own baseline with the measured values that result from the initial install of the printer that was installed per the manufacturer's QC procedure.

* OD = Optical Density

Printer manufacturer required QC manual followed:

SMPTE [%] Step Measured OD*

Passed Failed

100 1 l l90 2 l l80 3 l l70 4 l l60 5 l l50 6 l l40 7 l l30 8 l l20 9 l l10 10 l l0 11 l l

Compliance Yes No

Date _______________ l l

Date _______________ l l

Date _______________ l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



8. Appendix 2 – QC Forms Physicist Tests



For notes



Test Form 4.1 Site Audit / Evaluation of Technologist QC Program


1. List compression paddles that will be used routinely.

________________________________________

________________________________________

________________________________________

________________________________________

________________________________________

________________________________________

__________________________________________

2. Identify the mode chosen for technique selection.

_____ Opdose

_____ AEC H

_____ AEC D

_____ Manual

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



3. Define the Clinical Technique (used to image accreditation phantom).

Target material ___________________________

Filter material ___________________________

kVp ___________________________

This should also be the Target/Filter combination used for calibration

4. Will other Target/Filter combination be used clinically?

5. Technologist QC tests are being performed and are in compliance.

Yes which?

l

No

l

Yes No

l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 4.2 Mechanical Inspection


Mechanical Inspection and Follow Up

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Test no.: Performance criteria Passed Failed

1. WIPE breast support --- l l2. Check cables --- l l3. Control panel lights --- l l4. LED indicating tube close to floor --- l l5. Check motorized movements --- l l6. Movements blocked --- l l7. Compression self braking --- l l8. Manual compression buttons --- l l9. Decompression button --- l l10. Power driven compression --- l l11. No sharp edges --- l l



12. Foot switches --- l l13. Attachments --- l l14. Light Intensity Measurement Test

Value Acceptance Criteria Passed Failed

Area 1

Area 2

Area 3

Area 4

Mean Value > 160 lux l l15. Exposure control --- l l16. Emergency stop button --- l l

Comments: ________________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________



Test Form 4.3 Acquisition Workstation Monitor CheckNOTE!NOTE!


Acquisition Monitor Check and Viewing Conditions

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Gray Scale Contrast: Yes No

5% square is visible inside 0% square l lPerformance criteria: Yes

95% square is visible inside 100% square l lPerformance criteria: Yes

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Spatial resolution: Yes No

All lines in all bar patterns can be differentiated

l l

Performance criteria: Yes

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

Visual Inspection:

Yes No

Streaking l lPerformance criteria: No

Fluttering l lPerformance criteria: No

Shadows l lPerformance criteria: No

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 5.1 Detector Uniformity and Artifact Detection

NOTE!NOTE!Record the measured values on a copy of the Appendix pages and file it along with the QC-manual.

Detector uniformity

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Mo/Mo Mo/Rh W/Rh

Anode/Filter combination used l l l



Results from ROI statistics

Clinically Relevant Artifacts

Mean pixel value

% deviation from mean

Performance criteria

Passed Failed

Desired Required

Area 1 ≤ 5% ≤ 10% l lArea 2 ≤ 5% ≤ 10% l lArea 3 ≤ 5% ≤ 10% l lArea 4 ≤ 5% ≤ 10% l lArea 5 ≤ 5% ≤ 10% l lMean value

Comments: ______________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________

Anode/Filter combination Passed Failed

l l

l l

l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 5.2 Collimation, Dead Space and Compression Paddle Position


Collimator Assessmenta = f - e

b = f - g

ar is a on the right side.al is a on the left side.an is a on the nipple side.ac is a on the chest wall side.br is b on the right side.bl is b on the left side.bn is b on the nipple side.bc is b on the chest wall side.

If a is positive the X-ray field is larger than the detector area.If a is negative the X-ray field is smaller than the detector area.

If b is positive the X-ray field is larger than the detector area.If b is negative the X-ray field is smaller than the detector area.

a is the deviation between the X-ray field and the light field.b is the deviation between the X-ray field and the detector area.

α = value for dead space (See Compression Paddle Overlap on Chest Wall Side )

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



Measured Distances with Large Focus

e = ________________ mm

x = ________________ mm

y = ________________ mm

Mo/Mo Right edgeCoin 6

Left edgeCoin 2

Nipple-side edgeCoin 1

Chest-wall edgeCoin 4

f (mm)

a = f - e (mm)

| a | (mm)

g (mm)

b = f - g (mm)

| b | (mm)

W/Rh Right edgeCoin 6

Left edgeCoin 2

Nipple-side edgeCoin 1

Chest-wall edgeCoin 4

f (mm)

a = f - e (mm)

| a | (mm)

g (mm)

b = f - g (mm)

| b | (mm)



Sum of absolutevalues right and left

Performancecriteria

Large focus(Required) Passed Failed

Mo W

| ar | + | al | ≤ 13 mm l l

Sum of absolutevalues nipple and chest

Performancecriteria


Mo W

| an | + | ac | ≤ 13 mm l l

Sum of absolutevalues right and left

Performancecriteria


Mo W

| br | + | bl | ≤ 13 mm l l

Sum of absolutevalues nipple and chest

Performancecriteria


Mo W

| bn | + | bc | ≤ 13 mm l l

Sum of absolute values Performancecriteria


Mo W

| br | + | bl | + | bn | + | bc | ≤ 26 mm l l



Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Compression Paddle Overlap on Chest Wall Side

Compressionplates

Measured Ie - yI

Performancecriteria

No edges visible

Passed Failed

Yes No

≤ 6.5 mm l l l l

≤ 6.5 mm l l l l

≤ 6.5 mm l l l l

≤ 6.5 mm l l l l

≤ 6.5 mm l l l l

Comments: ____________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________



Chest Wall Missed Tissue

Performance criteria Passed Failed

Coin diameter IeI (mm):

Measured distance in the image IxI (mm):

Calculated chest wall missed tissue, α = Ie - xI ≤ 5 mm l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 5.3 AEC Thickness Tracking Test


Site: ______________________________________________________________

______________________________________________________________

Room: ______________________________________________________________

Type of test: ______________________________________________________________

Performed by: ______________________________________________________________

Date: ______________________________________________________________

Anode/Filter

combination

26 kV, 2 cm

PMMA

28 kV,4 cm

PMMA

32 kV, 6 cm

PMMA


Maximum Deviation

in %


Passed Failed

Mean l l

SD l l

SNR > 40 ≤ 15 % l l



For notes



Test Form 5.4 Spatial Resolution


Spatial Resolution

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter combination

kV mAs Best resolution visible (lp/mm)


Passed Failed

Mo / Mo ≥ 7 lp/mm l lW / Rh ≥ 7 lp/mm l l

Comments: _______________________________________________________________________________

_________________________________________________________________________________________

_________________________________________________________________________________________



For notes



Test Form 5.5 SNR, CNR and AEC repeatability


AEC Image Stability and Reproducibility and Signal-to-Noise Ratio (SNR)

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter: ________________________ kV: _________ H/D: _________

Expo-sure No

mAs SNR Mean from ROI

Entrance air kerma

(mGy)

SD CNR

1st

2nd

3rd

4th

5th



Anode/Filter

____________________

Value Performancecriteria

Passed Failed

Mean value(mAs)

SD Dev. (mAs)

Coefficient ofvariation(mAs)

≤ 5% l l

Mean value(Entrance air kerma)

SD Dev.(Entrance air kerma)

Coefficient of variation(Entrance air kerma)

≤ 5% l l

Mean value of“Mean”

Mean value ofSNR

Max. deviation“Mean” from Mean value ≤ 15% l lMax. deviationSNR from Mean value ≤ 15% l l

Comments: ________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________



Test Form 5.6 Image Quality and Radiation Dose


Phantom image quality

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter: Performancecriteria (RMI 156)

Passed Failed

kV:

mAs:

Fibers ≥ 5 l lSpeck Groups

≥ 4 l lMasses ≥ 4 l l

Comments: _______________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________



Mean Glandular DosemGy reading from the dose meter

HVL Values from Test Form 5.7 HVL and Radiation Output

Compression release

Compression thickness

AEC mode

kV Focus Anode/Filter mGy

H Large

D Large

Anode/Filter kVp Calculated HVL Values (mm Al)

Yes No

l l

Thickness Performancecriteria

Passed Failed

44 ≥ 3 mm l l



Pre-requisites to calculate the mean glandular dose

Use formulae:

D=Kgcs*

D Mean glandular dose

K Entrance air kerma

g g-factor for breasts simulated with PMMA

c c-factor for breasts simulated with PMMA

s s-factor for clinically used spectra

Where K is the incident air kerma (without backscatter) calculated at the upper surface of the PMMA. The factor g, corresponds to a glandularity of 50%, and is derived from the values calculated* and is shown below for a range of HVL. The c-factor corrects for the difference in composition of typical breasts from 50% glandularity* and is given here for typical breasts in the age range 50 to 64. Note that the c and g-factors applied are those for the corresponding thickness of typical breast rather than the thickness of PMMA block used. Where necessary interpolation may be made for different values of HVL. The factor s shown in the second table corrects for any difference due to the choice of X-ray spectrum*.

* [D.R. Dance, C.L. Skinner, K.C. Young, J.R. Beckett. C.J. Kotre: Additional factors for the estimation of mean glandular breast dose using the UK mammography dosimetry protocolPhysics in Medicine and Biology 45, 3225-3240, 2000]

PMMA thickness

(mm)

Equivalent breast

thickness (mm)

HVL (mm Al)

0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60

g-factor 45 53 0.130 0.155 0.177 0.198 0,220 0.245 0,272 0,295

c-factor 45 53 - 1.109 1.105 1.102 1.099 1.096 1.091 1.088

g-factor 50 60 0.112 0.135 0.154 0.172 0.192 0.214 0.236 0.261

c-factor 50 60 - 1.164 1.160 1.151 1.150 1.144 1.139 1.134

Mo/Mo Mo/Rh W/Rh

s-factor 1.000 1.017 1.042



Calculate the mean glandular dose

AECmode

Anode/Filter: ________

kV: ________

mAs: ________

Performancecriteria

Passed Failed

Desired(mGy)

Required(mGy)

D=Kgcs H

≤ 2 ≤ 3l l

D=Kgcs D l l

Comments: ___________________________________________________________________________

______________________________________________________________________________________

______________________________________________________________________________________



Test Form 5.7 HVL and Radiation OutputNOTE!NOTE!


Beam Quality (HVL)Only the column for the anode/filter combination used for HVL measurement shall be filled out:

Observe that all fields may not be needed for the different anode/filter combinations.

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Anode/Filter Mo/Mo kVp ______ Mo/Rh kVp ______ W/Rh kVp ______

Exposure reading without Al (D0)

Exposure reading 0.2 mm Al





Second exposure reading without Al (must not differ more than 2% from D0)



Calculated HVL ValuesOnly the row for the anode/filter combination used for HVL measurement shall be filled out:

Radiation OutputmGy reading from the dose meter

Anode/Filtercombination

Calculated HVLValues (mm Al)

Criteria for HVL value at 28 kVp

(kVp/100)

Passed Failed

Mo/Mo ≥ 0.28 l lMo/Rh ≥ 0.28 l lW/Rh ≥ 0.28 l l

Deviation between first and last exposure

≤ 2% l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

Anode/Filter

kV mAs Distance above breast support surface (mm)

mGy / mR

Sec mGy/s / mR/s

Performancecriteria

Passed Failed

Mo/Mo 28 400 45 > 7 mGy/s / > 800 mR/s

l l

Comments: _________________________________________________________________________________

___________________________________________________________________________________________

___________________________________________________________________________________________



Test Form 5.8 Tube Voltage Measurement & Reproducibility


Tube voltage and reproducibility

Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________

Parameters kVpmeas kVpmean Coefficient of variation


Passed Failed

1st exposure________ kVp, 50 mAs, Mo/Mo

< 2 % l l

2nd exposure________ kVp, 50 mAs, Mo/Mo

< 2 % l l

3rd exposure________ kVp, 50 mAs, Mo/Mo

< 2 % l l

4th exposure________ kVp, 50 mAs, Mo/Mo

< 2 % l l



Parameters kVpmeas Performance criteria Passed Failed

26 kVp Accuracy: ≤ 5 % kV l l28 kVp Accuracy: ≤ 5 % kV l l30 kVp Accuracy: ≤ 5 % kV l l32 kVp Accuracy: ≤ 5 % kV l l34 kVp Accuracy: ≤ 5 % kV l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 5.9 Printer Check



Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



Printer Check


Customer values for Min and Max Density

Min Density

Max Density

Step Corr16b-bspline (LUT) Linear LUT*

Ref. LUT

Maximum-density

Minimum density

Ref. Density

Maximum density

Minimum density

1 0.20 0.23 0.17 0.20 0.23 0.17

2 0.34 0.38 0.30 0.52 0.56 0.49

3 0.47 0.51 0.43 0.86 0.90 0.82

4 0.64 0.69 0.59 1.18 1.23 1.13

5 0.81 0.87 0.75 1.52 1.58 1.46

6 1.05 1.12 0.99 1.84 1.91 1.78

7 1.31 1.38 1.24 2.18 2.25 2.11

8 1.66 1.74 1.58 2.52 2.60 2.44

9 2.10 2.19 2.01 2.85 2.94 2.77

10 2.68 2.77 2.59 3.18 3.27 3.08

11 3.50 3.60 3.40 3.50 3.60 3.40


Ref. LUT Maximumdensity

Minimumdensity

1 0.20 0.23 0.17

2 0.44 0.48 0.40

3 0.68 0.72 0.64

4 0.94 0.99 0.89

5 1.18 1.24 1.12

6 1.45 1.52 1.39

7 1.73 1.80 1.66

8 2.01 2.09 1.93

9 2.32 2.41 2.23

10 2.73 2.82 2.64

11 3.50 3.60 3.40




Step Corr16b-bspline (LUT)

Ref. LUT*

Recommenda-tion Maximum

density


density

Required Maximum density

RequiredMinimum density

1 0.20 0.23 0.17 0.30 0.10

2 0.34 0.38 0.30 0.44 0.24

3 0.47 0.51 0.43 0.57 037

4 0.64 0.69 0.59 0.74 0.54

5 0.81 0.87 0.75 0.91 0.71

6 1.05 1.12 0.99 1.15 0.95

7 1.31 1.38 1.24 1.41 1.21

8 1.66 1.74 1.58 1.76 1.56

9 2.10 2.19 2.01 2.20 2.00

10 2.68 2.77 2.59 2.78 2.58

11 3.50 3.60 3.40 3.60 3.40


Ref. LUT Recommenda-tion Maximum

density


density

Required Maximumdensity

Required Minimumdensity

1 0.20 0.23 0.17 0.30 0.10

2 0.44 0.48 0.40 0.54 0.34

3 0.68 0.72 0.64 0.68 0.58

4 0.94 0.99 0.89 1.04 0.84

5 1.18 1.24 1.12 1.28 1.08

6 1.45 1.52 1.39 1.55 1.35

7 1.73 1.80 1.66 1.83 1.53

8 2.01 2.09 1.93 2.11 1.91

9 2.32 2.41 2.23 2.42 2.22

10 2.73 2.82 2.64 2.83 2.63

11 3.50 3.60 3.40 3.60 3.40



If your values do not meet the values specified above, then please refer to the printer manufacturer's quality control procedure. You can create your own baseline with the measured values that result from the initial install of the printer that was installed per the manufacturer's QC procedure.

* OD = Optical Density

Printer manufacturer required QC manual followed:

SMPTE [%] Step Measured OD*

Passed Failed

100 1 l l90 2 l l80 3 l l70 4 l l60 5 l l50 6 l l40 7 l l30 8 l l20 9 l l10 10 l l0 11 l l

Compliance Yes No

Date _______________ l l

Date _______________ l l

Date _______________ l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________



Test Form 6.1 Ghost Image Evaluation


Site: ___________________________________________________

___________________________________________________

Room: ___________________________________________________

Type of test: ___________________________________________________

Performed by: ___________________________________________________

Date: ___________________________________________________



Ghost Image Evaluation

Area Mean pixel value

PV1 PV2

1

2

3

4

Anode/Filter:_________

kV: _________

mAs: _________


Passed Failed

Ghost image factor < 3 % l l

Comments: _______________________________________________________________________________

__________________________________________________________________________________________

__________________________________________________________________________________________

Order No.: SPB7-250.623.50.05.24Printed in the Federal Republic of GermanyAG 04/07

© Siemens AG 2007All rights reserved

Contact Address:

Siemens AG Siemens AG, Medical SolutionsWittelsbacherplatz 2 Special SystemsD-80333 München Henkestraße 127Germany D-91052 Erlangen

Germany

Documents

Siemens MAMMOMAT Novation DR Quality Control Manual