Siemens MAMMOMAT Novation DR Quality Control Manual

Quality Control Manual MAMMOMAT Novation DR Order No: SPB7-250.623.50.05.24 Version 05 / AG 04/07

Siemens AG Medical Solutions Special Systems Henkestraße 127 D-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 English language.

Contents 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 .................................................................................... 22 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5

Objective ........................................................................................................................ 22 Required Equipment....................................................................................................... 22 Procedure....................................................................................................................... 22 Analysis .......................................................................................................................... 25 Performance Criteria and Corrective Action ................................................................... 26

MAMMOMAT NovationDR SPB7-250.623.50.05.24

3

Contents 3.2 Detector Calibration ..........................................................................................27 3.2.1 Objective......................................................................................................................... 27 3.2.2 Required Equipment....................................................................................................... 27 3.2.3 Procedure ....................................................................................................................... 27

3.3 Artifact Detection...............................................................................................30 3.3.1 3.3.2 3.3.3 3.3.4

Objective......................................................................................................................... 30 Required Equipment....................................................................................................... 30 Procedure ....................................................................................................................... 30 Performance Criteria and Corrective Action ................................................................... 31

3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements ...............................................32 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5

Objective......................................................................................................................... 32 Required Equipment....................................................................................................... 32 Procedure ....................................................................................................................... 32 Analysis .......................................................................................................................... 34 Performance Criteria and Corrective Action ................................................................... 34

3.5 Repeat Analysis ................................................................................................35 3.5.1 3.5.2 3.5.3 3.5.4

Objective......................................................................................................................... 35 Procedure ....................................................................................................................... 35 Analysis .......................................................................................................................... 36 Performance Criteria and Corrective Action ................................................................... 36

3.6 Compression Force...........................................................................................37 3.6.1 3.6.2 3.6.3 3.6.4


3.7 Printer Check ....................................................................................................38 3.7.1 3.7.2 3.7.3 3.7.4


4. Initial Checks - Physicist

39

4.1 Site Audit / Evaluation of Technologist QC Program ........................................39 4.1.1 Objective......................................................................................................................... 39 4.1.2 Procedure ....................................................................................................................... 39

4.2 Mechanical Inspection ......................................................................................40 4.2.1 Objective......................................................................................................................... 40 4.2.2 Procedure ....................................................................................................................... 40

4.3 Acquisition Workstation Monitor Check ............................................................43 4.3.1 4.3.2 4.3.3 4.3.4

4


Quality Control Manual SPB7-250.623.50.05.24

Contents 5. Required Tests - Physicist

45

5.1 Detector Uniformity and Artifact Detection ....................................................... 45 5.1.1 5.1.2 5.1.3 5.1.4

Objective ........................................................................................................................ 45 Required Equipment....................................................................................................... 45 Procedure....................................................................................................................... 45 Performance Criteria and Corrective Action ................................................................... 47

5.2 Collimation, Dead Space and Compression Paddle Position ........................... 48 5.2.1 5.2.2 5.2.3 5.2.4


5.3 AEC Thickness Tracking Test .......................................................................... 52 5.3.1 5.3.2 5.3.3 5.3.4


5.4 Spatial Resolution............................................................................................. 54 5.4.1 Objective ........................................................................................................................ 54 5.4.2 Procedure....................................................................................................................... 54 5.4.3 Performance Criteria and Corrective Action ................................................................... 55

5.5 SNR, CNR and AEC repeatability .................................................................... 56 5.5.1 5.5.2 5.5.3 5.5.4 5.5.5


5.6 Image Quality and Radiation Dose ................................................................... 59 5.6.1 5.6.2 5.6.3 5.6.4 5.6.5


5.7 HVL and Radiation Output................................................................................ 63 5.7.1 5.7.2 5.7.3 5.7.4 5.7.5

Objective ........................................................................................................................ 63 Required Equipment....................................................................................................... 63 Procedure....................................................................................................................... 63 Calculating HVL.............................................................................................................. 65 Performance Criteria and Corrective Action ................................................................... 65

5.8 Tube Voltage Measurement & Reproducibility ................................................. 66 5.8.1 5.8.2 5.8.3 5.8.4 5.8.5

Objective ........................................................................................................................ 66 Required Equipment....................................................................................................... 66 Procedure....................................................................................................................... 66 Calculations .................................................................................................................... 67 Performance Criteria and Corrective Action ................................................................... 68


5

Contents 5.9 Printer Check ....................................................................................................69 5.9.1 5.9.2 5.9.3 5.9.4


6. Optional Test

70

6.1 Ghost Image Evaluation....................................................................................70 6.1.1 6.1.2 6.1.3 6.1.4 6.1.5

Objective......................................................................................................................... 70 Required Equipment....................................................................................................... 70 Pre Requisites ................................................................................................................ 70 Procedure ....................................................................................................................... 70 Performance Criteria and Corrective Action ................................................................... 72

7. Appendix 1 – QC Forms Technologist Tests

73

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

Test Form 3.2 Detector Calibration ...........................................................................77 Test Form 3.3 Artifact Detection................................................................................79 Clinically Relevant Artifacts ....................................................................................................... 79

Test Form 3.4 Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements........................................................81 Signal-to-Noise Ratio and Contrast-To-Noise Ratio Measurements ......................................... 82

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

Test Form 3.6 Compression Force............................................................................85 Test Form 3.7 Printer Check .....................................................................................87 Printer 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 .......................................................................95 Mechanical Inspection and Follow Up ....................................................................................... 95

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

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

6


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

Test Form 5.3 AEC Thickness Tracking Test ......................................................... 107 Test Form 5.4 Spatial Resolution............................................................................ 109 Spatial Resolution.................................................................................................................... 109

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

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

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

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

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

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


7

Contents

8


Tables List of Tables Table 1 Table 2 Table 3 Table 4 Table 5

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


9

Tables

10


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 8


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 24


Figure 25

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

Figure 26

Image Attributes........................................................................................ 64

Figure 27

Ghosting 180 sec measurement. .............................................................. 71


11

Figures

12


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


13

Abbreviations For notes

14


Introduction Mammography 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.


15

Introduction Soft Copy Viewing Station

1.6 Soft Copy Viewing Station When 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/Printer When using a laser camera/printer to print mammographic or accreditation images, the printer manufacturer's QC procedure must be followed.

16


Introduction Frequency of Required Tests - Technologist

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

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.

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.


17

Introduction Recommended Frequency of QC Tests - Medical Physicist

1.9 Recommended Frequency of QC Tests - Medical Physicist Table 2 describes when the tests must be performed by the 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

Table 2

18

MEE, Annually

Frequency of QC Tests - Medical Physicist


Introduction Important Notes

1.10 Important Notes While 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.

1.11 Required Corrective Action Whenever 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.


19

Introduction Required Equipment - Annual Survey, MEE

1.12 Required 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 performed without compression paddle attached. Detach compression paddle and insert metal plug compression paddle simulator. Radiation field 24x29 cm.

20


Start Up and Login Procedure

2. Start Up and Login 2.1 Procedure 1.

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!

3.

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.

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.


21

Required Tests - Technologist Phantom Image Quality

3. Required Tests - Technologist 3.1 Phantom Image Quality 3.1.1 Objective To ensure that adequate image quality is achieved.

3.1.2 Required Equipment a)

Accreditation phantom

b)

Compression paddle 24x30

3.1.3 Procedure 1.

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

22


Required Tests - Technologist Phantom Image Quality 3.

Create a new patient record in the local database, see Figure 7. Fill in: Last Name: Test_One First Name: Phantom Image Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: 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.


23

Required Tests - Technologist Phantom Image Quality 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.

24



XXX XXX

Fibers

Specks

Masses

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.


25


3.1.5 Performance Criteria and Corrective Action 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. Phantom used


Table 3

Required Fibers

≥5

Speck groups

≥4

Masses

≥4

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.

26


Required Tests - Technologist Detector Calibration

3.2 Detector Calibration 3.2.1 Objective To determine that the system has been correctly calibrated with respect to its gain.


Collimator mounted PMMA phantom (40 mm thick)

b)

Compression paddle simulator

3.2.3 Procedure Calibration 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.

8.


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.


27

Required Tests - Technologist Detector Calibration

Figure 5 Calibration image

28


Required Tests - Technologist Detector Calibration 10. Click Accept if the image is suitable for the calibration, see Figure 6. Or Click 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

12. Choose the Close patient tab card and close patient by clicking this button. 13. Proceed to section 3.3 Artifact Detection.


29

Required Tests - Technologist Artifact Detection

3.3 Artifact Detection 3.3.1 Objective To determine if the detector is dusty, damaged, or has other artifacts.


Collimator mounted PMMA phantom (40 mm thick)

b)


3.3.3 Procedure 1.

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

2.


3.

Create a new patient record in the local database, see Figure 7. Fill in: Last Name: Test_Three First Name: Artifact_Detect Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.

Choose procedure FD QC Raw.

6.

Mount a compression paddle simulator.

7.

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

8.


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

30


Required Tests - Technologist Artifact Detection

3.3.4 Performance Criteria and Corrective Action No clinically relevant artifacts shall be seen on 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.

Figure 7 Patient Registration Window


31

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

3.4 Signal-to-Noise Ratio (SNR) and Contrast-ToNoise Ratio (CNR) Measurements 3.4.1 Objective To assure proper functioning of the solid-state detector by evaluating the signal-tonoise 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.



b)


3.4.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Four First Name: SNR_CNR Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


6.


7.

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


32


Required Tests - Technologist Signal-to-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements 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.

9.


10. Make an exposure. 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 Signalto-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements.

Mass ROI Background ROI

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


33

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

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

( mean background – DC offset ) SNR = -------------------------------------------------------------------------SD background Where the DCoffset has a value of 50. CNR should be calculated by using the values in Appendix 1, Test Form 3.4 Signalto-Noise Ratio (SNR) and Contrast-To-Noise Ratio (CNR) Measurements, and the following formula:

( mean background – mean mass ) CNR = -----------------------------------------------------------------------------SD background Deviation from the baseline value (determined during the mammography equipment evaluation) can be calculated by using the following formula:

( Baseline – ActualValue ) Deviation = ------------------------------------------------------------------------- × 100 Baseline

3.4.5 Performance Criteria and Corrective Action The 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. 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.

34


Required Tests - Technologist Repeat Analysis

3.5 Repeat Analysis 3.5.1 Objective To monitor the causes of repeated patient exposures as part of an effort to correct any problems that might exist.

3.5.2 Procedure 1.

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.


35

Required Tests - Technologist Repeat Analysis

3.5.3 Analysis 1.

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.

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

3.5.4 Performance Criteria and Corrective Action If 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.

36


Required Tests - Technologist Compression Force

3.6 Compression Force 3.6.1 Objective To measure the compression force in Opcomp and the full automatic max/min and manual (optional) mode of operation.


Bathroom scale or compression force measurement tool

b)

Stiff foam block or towel

3.6.3 Procedure 1.

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.

mm OC

OC

F

o

F

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 Action Maximum automated compression must be between 12 and 20 kg (25 - 45 pounds).


37

Required Tests - Technologist Printer Check

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

3.7.1 Objective To assess the quality of the laser camera.


Calibrated densitometer

3.7.3 Procedure 1.


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

38


Initial Checks - Physicist Site Audit / Evaluation of Technologist QC Program

4. Initial Checks - Physicist 4.1 Site Audit / Evaluation of Technologist QC Program 4.1.1 Objective To determine the site settings. To ensure compliance to the Technologist QC tests. Refer to Table 1.

4.1.2 Procedure 1.

List all compression paddles that will be used routinely in Appendix 2, Test Form 4.1 Site Audit / Evaluation of Technologist QC Program

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.


39

Initial Checks - Physicist Mechanical Inspection

4.2 Mechanical Inspection 4.2.1 Objective Acceptance 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 Procedure 1.

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

40


Initial Checks - Physicist Mechanical Inspection 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.

Maximum compression force presetting knob

MAM00664

Knobs for manual compression/decompression

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.


41

Initial Checks - Physicist Mechanical Inspection 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. Light field 1

2

4

3

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.

42


Initial Checks - Physicist Acquisition Workstation Monitor Check

4.3 Acquisition Workstation Monitor Check 4.3.1 Objective To assess the quality of the acquisition workstation monitor.


SMPTE test pattern

4.3.3 Procedure 1.

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.

5%

95 %

Figure 15 Location of Squares


43

Initial Checks - Physicist Acquisition 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

9.

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

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. 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.

44


Required Tests - Physicist Detector Uniformity and Artifact Detection

5. Required Tests - Physicist 5.1 Detector Uniformity and Artifact Detection 5.1.1 Objective To measure the uniformity of the detector response over its entire surface and to determine if the detector is dusty, damaged, or has other artifacts.


Collimator mounted plexi (40 mm)

b)


5.1.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_One First Name: Detector Uniformity Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


6.

Install the collimator-mounted plexi (40 mm).

7.

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

8.


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.


45

Required Tests - Physicist Detector Uniformity and Artifact Detection 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.

Mean Value Figure 18 ROI Statistics

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

46


Required Tests - Physicist Detector Uniformity and Artifact Detection 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. 20. Choose the Close patient tab card and close patient by clicking this button.

5.1.4 Performance Criteria and Corrective Action The 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


47

Required Tests - Physicist Collimation, 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.


Seven identical coins

b)

Ruler

c)

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

d)

Film or CR cassette (24x30 or larger)

5.2.3 Procedure

48

1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Two First Name: Chest Wall Missed Tissue Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

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.


Required Tests - Physicist Collimation, Dead Space and Compression Paddle Position 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


49

Required Tests - Physicist Collimation, Dead Space and Compression Paddle Position

Figure 20 Placing the Coins

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

50


Required Tests - Physicist Collimation, Dead Space and Compression Paddle Position 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. 27. Choose the Close patient tab card and close patient by clicking this button.

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. 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.


51

Required Tests - Physicist AEC Thickness Tracking Test

5.3 AEC Thickness Tracking Test 5.3.1 Objective To assure that the AEC function is tracking by evaluation images acquired with different thicknesses and techniques.


Three PMMA absorbers, 20 mm thick each

b)


5.3.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Three First Name: AEC Tracking Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

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).

PMMA

Figure 21 Positioning the PMMA (seen from above)

7.

52



Required Tests - Physicist AEC 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

9.


10. Make an exposure. 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:

( mean background – DC offset ) SNR = -------------------------------------------------------------------------SD background Where the DCoffset has a value of 50. 13. Repeat the same procedure from step 8 - 13 for all thicknesses and techniques listed in step 8. 14. Choose the Close patient tab card and close patient by clicking this button. 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 Action The minimum SNR must be ≥ 40 and the maximum deviation from the mean value must be ≤ ±15 %. 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.


53

Required Tests - Physicist Spatial Resolution

5.4 Spatial Resolution 5.4.1 Objective To ensure that adequate spatial resolution is obtained with the MAMMOMAT NovationDR system. a)

Line pair phantom

b)

40 mm (PMMA) phantom

c)


5.4.2 Procedure

54

1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Four First Name: Spatial Resolution Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


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 - Physicist Spatial 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.

45 AEC 3

Figure 22 Placing the Resolution Phantom

9.


10. Make an exposure. 11. Examine the image and starting with the largest bars determine the highest linepair 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. 12. Choose the Close patient tab card and close patient by clicking this button.

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


55

Required Tests - Physicist SNR, CNR and AEC repeatability

5.5 SNR, CNR and AEC repeatability 5.5.1 Objective To assure proper functioning of the solid-state detector by evaluating the signal-tonoise 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.


Dosimeter calibrated at the mammography X-ray beam energies

b)


c)


5.5.3 Procedure

56

1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Five First Name: AEC Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


6.


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.


Required Tests - Physicist SNR, CNR and AEC repeatability 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

11. Double click on the first image in the icon gallery, see Figure 3, Position 2. 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. 18. Choose the Close patient tab card and close patient by clicking this button.


57

Required Tests - Physicist SNR, CNR and AEC repeatability

5.5.4 Analysis SNR 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:

( mean background – DC offset ) SNR = -------------------------------------------------------------------------SD background Where the DCoffset has a value of 50. CNR should be calculated by using the values in Appendix 2, Test Form 5.5 SNR, CNR and AEC repeatability, and the following formula:

( mean background – mean mass ) CNR = -----------------------------------------------------------------------------SD background 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 Action The 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. 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.

58


Required Tests - Physicist Image Quality and Radiation Dose

5.6 Image Quality and Radiation Dose 5.6.1 Objective To 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)


c)


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

5.6.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Six First Name: Mean Glandular Dose Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.

Choose procedure FD QC processed.

6.


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.


59



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.

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

XXX XXX

Fibers

Specks

Masses

Figure 25 Potentially Visible Objects in the accreditation phantom

60


Required Tests - Physicist Image Quality and Radiation Dose 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). 17. Choose the Close patient tab card and close patient by clicking this button.

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.


61


5.6.5 Performance Criteria and Corrective Action The 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. Phantom used


Table 4

Required Fibers

≥5

Speck groups

≥4

Masses

≥4

Object Score Criteria for the accreditation phantom Test


62


Required Tests - Physicist HVL and Radiation Output

5.7 HVL and Radiation Output 5.7.1 Objective Calculate the half value layer (HVL) from measured exposure data. The HVL value obtained 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.

5.7.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Seven First Name: HVL Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


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.

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


63

Required Tests - Physicist HVL and Radiation Output 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 20. Choose the Close patient tab card and close patient by clicking this button. 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.

64


Required Tests - Physicist HVL and Radiation Output

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

( t b ⋅ ln [ 2D a ⁄ D 0 ] ) – ( t a ⋅ ln [ 2D b ⁄ D 0 ] ) = --------------------------------------------------------------------------------------ln [ D a ⁄ D b ]

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 Action The radiation output rate must be higher than 7.0 mGy air kerma per second, alternatively 800 mR per second.

Anode/Filter

HVL value at 28kVp (kVp/100)

Mo/Mo

≥ 0.28

Mo/Rh

≥ 0.28

W/Rh

≥ 0.28

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. 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.


65

Required Tests - Physicist Tube Voltage Measurement & Reproducibility

5.8 Tube Voltage Measurement & Reproducibility 5.8.1 Objective To verify that the accuracy of the tube voltage value displayed is in accordance with the specifications.


Non-invasive kVp meter calibrated in the mammography range.

b)


c)

2 mm steel plate

5.8.3 Procedure 1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_Eight First Name: Tube Voltage Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


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.)

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

66


Required Tests - Physicist Tube Voltage Measurement & Reproducibility 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. 13. Choose the Close patient tab card and close patient by clicking this button.

5.8.4 Calculations These calculations can be easily performed with an inexpensive calculator. 1.

Formula for Accuracy (expressed in percent):

kV p meas – kVp set ---------------------------------------------- × 100 kVp set

kVpmeas = = kVpset 2.

Measured kVp The set value of the tube voltage

Coefficient of variations Cv (expressed in percent):

1--2 n ( kVp – kVp 2 1 i mean ) - × 100 Cv = ------------------------ ∑ ------------------------------------------------kVp mean n–1 i=1

Mean value for the tube voltage measurement: kVp 1 + kVp 2 + kVp 3 + kVp 4 kVpmean = ----------------------------------------------------------------------4 kVpi n


= The sampled measurement = The number of measurements sampled (n here = 4)

67

Required Tests - Physicist Tube Voltage Measurement & Reproducibility Example: Calculating the kVp reproducibility coefficient of variations Cv: a) Settings: kVpset = 27kVp, 50mAs and Mo/Mo Record the four consecutive measurements and calculate the mean value kVpmean in Appendix 2, Test Form 5.8 Tube Voltage Measurement & Reproducibility. 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

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

0.05

-0.05

-0.15

0.15

Difference squared

0.0025

0.0025

0.0225

0.0225

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. 1

0.0167 2 ∗100 = 0.476% ≈ 0.5% 27.15

The result is within the specified design criteria.

5.8.5 Performance Criteria and Corrective Action Accuracy:

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%.


68


Required Tests - Physicist Printer Check

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

5.9.1 Objective To assess the quality of the laser camera.


Calibrated densitometer

5.9.3 Procedure 1.


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


69

Optional Test Ghost Image Evaluation

6. Optional Test 6.1 Ghost Image Evaluation 6.1.1 Objective Ghosting 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.


2 mm steel plate (breast support)

b)

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

c)

40 mm PMMA phantom (collimator mounted)

d)


e)

4 paper clips

f)

Timer

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

6.1.4 Procedure

70

1.


2.


3.

Create a new patient record in the local database. Fill in: Last Name: Test_One First Name: Ghosting Patient ID: day+time when the test is performed (example: 200411281350) DOB: 05 05 1955 Gender: Other

4.

Press Exam button.

5.


6.

Cover the FD object table with the 2 mm steel.


Optional Test Ghost Image Evaluation 7.

Install a compression paddle simulator.

8.


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. Position 2

Position 3

Steel bar Paper clip

Position 1 Second exposure

Position 4 Third exposure after 180 seconds

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.


71

Optional Test Ghost Image Evaluation 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. 17. Choose the Close patient tab card and close patient by clicking this button. 18. Calculate the ghosting in percent [%] according to:

( PV1 – PV2 ) Ghosting = 200 ⋅ ----------------------------------PV1 + PV2

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

72


Appendix 1 to MAMMOMAT NovationDR QC Manual

7. Appendix 1 – QC Forms Technologist Tests


73


For notes

74



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.

Site:

___________________________________________________ ___________________________________________________

Room:

___________________________________________________

Type of test:

___________________________________________________

Performed by:

___________________________________________________

Date:

___________________________________________________

Phantom image quality Anode/Filter:

Performance criteria (RMI 156)

Passed

Failed

Fibers

≥5

Speck Groups

≥4

l l

l l

Masses

≥4

l

l

kV: mAs:

Comments: _______________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________


75


For notes

76



Test Form 3.2 Detector Calibration NOTE! 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




77


Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ Review: ____________________________________

78

Date: ______________________________________



Test Form 3.3 Artifact Detection NOTE! 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:

___________________________________________________

Clinically Relevant Artifacts Anode/Filter combination

Passed

Failed

l

l

l

l

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________


79


For notes

80



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

___________________________________________________


81


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

Mean Mass

SD Dev. SNR Background

CNR

Deviation Deviation Performance SNR CNR criteria

Passed

Failed

Baseline 1st

SNR: ≥ 40

Dev SNR: ± 15%

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

Dev CNR: ± 15%

2nd

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

3rd

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

4th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

5th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

6th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

7th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

8th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

9th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

10th

SNR: ≥ 40

Dev SNR: ± 15%

Dev CNR: ± 15%

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

82



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.

NOTE! 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:

___________________________________________________

Mammography Repeat Analysis From

________________________

Categories

to

________________________

Projection Repeated (mark one for each repeated image) Left CC

Right CC

Left MLO

Right MLO

Left Other

Right Other

Number of discarded images/ repeated images

% of discarded images

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)


83


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 number of discarded images/ repeated images

Corrective actions

Yes

No

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

Corrective actions: _________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

84



Test Form 3.6 Compression Force NOTE! 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:

___________________________________________________

Value

Performance Criteria

Passed

Failed

Force Opcomp Maximum Force Automatic

Force between 12 and 20 kg

l

l

Maximum Force Manually (optional)

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________


85


For notes

86



Test Form 3.7 Printer Check Printer manufacturer's QC procedure must be followed whenever the printer is used to print mammographic images or accreditation images.

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:

___________________________________________________


87


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. 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

* LUT = Look-Up-Table

Step

88

MG1_5bCorr-bspline (LUT) Ref. LUT

Maximum density

Minimum density

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*

Recommendation Maximum density

Recommendation Minimum density

Required Maximum density

Required Minimum 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


Step






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


89


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.

SMPTE [%]

Step

Measured OD*

Passed

Failed

100

1

l

l

90

2

l

l

80

3

l

l

70

4

l

l

60

5

l

l

50

6

l

l

40

7

l

l

30

8

l

l

20

9

l

l

10

10

l

l

0

11

l

l

* OD = Optical Density

Printer manufacturer required QC manual followed: Compliance

Yes

No

Date _______________

l

l

Date _______________

l

l

Date _______________

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

90



8. Appendix 2 – QC Forms Physicist Tests


91


For notes

92



Test Form 4.1 Site Audit / Evaluation of Technologist QC Program NOTE! 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:

___________________________________________________

1. List compression paddles that will be used routinely. ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ __________________________________________

2. Identify the mode chosen for technique selection. _____

Opdose

_____

AEC H

_____

AEC D

_____

Manual


93


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?

Yes

which?

l

No

l

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

Yes

No

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

94



Test Form 4.2 Mechanical Inspection NOTE! 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:

___________________________________________________

Mechanical Inspection and Follow Up Test no.:

Performance criteria

Passed

Failed

1. WIPE breast support

---

2. Check cables

---

3. Control panel lights

---

4. LED indicating tube close to floor

---

5. Check motorized movements

---

6. Movements blocked

---

7. Compression self braking

---

8. Manual compression buttons

---

9. Decompression button

---

10. Power driven compression

---

11. No sharp edges

---

l l l l l l l l l l l

l l l l l l l l l l l


95


l l

l l

Acceptance Criteria

Passed

Failed

> 160 lux

l l l

l l l

12. Foot switches

---

13. Attachments

---

14. Light Intensity Measurement Test Value Area 1 Area 2 Area 3 Area 4 Mean Value 15. Exposure control

---

16. Emergency stop button

---

Comments: ________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

96



Test Form 4.3 Acquisition Workstation Monitor Check NOTE! 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:

___________________________________________________

Acquisition Monitor Check and Viewing Conditions Gray Scale Contrast:

Yes

No

5% square is visible inside 0% square

l

l

Performance criteria: Yes 95% square is visible inside 100% square

l

l

Performance criteria: Yes

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________


97


Spatial resolution:

Yes

No

All lines in all bar patterns can be differentiated

l

l

Performance criteria: Yes

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

Visual Inspection:

Streaking

Yes

No

l

l

Performance criteria: No Fluttering

l

l

Performance criteria: No Shadows

l

l

Performance criteria: No

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

98



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.

Site:

___________________________________________________ ___________________________________________________

Room:

___________________________________________________

Type of test:

___________________________________________________

Performed by:

___________________________________________________

Date:

___________________________________________________

Detector uniformity Anode/Filter combination used


Mo/Mo

Mo/Rh

W/Rh

l

l

l

99


Results from ROI statistics Mean pixel value

% deviation from mean

Performance criteria Desired

Required

Area 1

≤ 5%

≤ 10%

Area 2

≤ 5%

≤ 10%

Area 3

≤ 5%

≤ 10%

Area 4

≤ 5%

≤ 10%

Area 5

≤ 5%

≤ 10%

Passed

Failed

l l l l l

l l l l l

Mean value

Comments: ______________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

Clinically Relevant Artifacts Anode/Filter combination

Passed

Failed

l

l

l

l

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

100



Test Form 5.2 Collimation, Dead Space and Compression Paddle Position NOTE! 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:

___________________________________________________

Collimator Assessment a=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 )


101


Measured Distances with Large Focus

Mo/Mo

Right edge Coin 6

Left edge Coin 2

Nipple-side edge Coin 1

Chest-wall edge Coin 4

f

(mm)

a=f-e

(mm)

|a|

(mm)

g

(mm)

b=f-g

(mm)

|b|

(mm)

W/Rh

Right edge Coin 6

Left edge Coin 2

Nipple-side edge Coin 1

Chest-wall edge Coin 4

f

(mm)

a=f-e

(mm)

|a|

(mm)

g

(mm)

b=f-g

(mm)

|b|

(mm)

e = ________________ mm x = ________________ mm y = ________________ mm

102



Sum of absolute values right and left


Large focus (Required) Mo

| ar | + | al |

≤ 13 mm

Sum of absolute values nipple and chest


| an | + | ac |

≤ 13 mm

Sum of absolute values right and left


| br | + | bl |

≤ 13 mm

Sum of absolute values nipple and chest


| bn | + | bc |

≤ 13 mm

Sum of absolute values


| br | + | bl | + | bn | + | bc |


≤ 26 mm

Passed

Failed

l

l

Passed

Failed

l

l

Passed

Failed

l

l

Passed

Failed

l

l

W


l

W


l

W


Failed

W


Passed

W

103


Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

104



Compression Paddle Overlap on Chest Wall Side

Compression plates

Measured Ie - yI


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: ____________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________


105


Chest Wall Missed Tissue Performance criteria

Passed

Failed

≤ 5 mm

l

l

Coin diameter IeI (mm): Measured distance in the image IxI (mm): Calculated chest wall missed tissue, α = Ie - xI

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

106



Test Form 5.3 AEC Thickness Tracking Test NOTE! 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:

______________________________________________________________

Anode/ Filter combination

26 kV, 28 kV, 32 kV, Performance Maximum Performance Passed 6 cm criteria Deviation criteria 2 cm 4 cm PMMA PMMA PMMA in %

Failed

Mean

l

l

SD

l

l

l

l

SNR


> 40

≤ 15 %

107


For notes

108



Test Form 5.4 Spatial Resolution NOTE! 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:

___________________________________________________

Spatial Resolution Anode/Filter combination

kV

mAs

Best resolution visible (lp/mm)


Passed

Failed

Mo / Mo

≥ 7 lp/mm

l

l

W / Rh

≥ 7 lp/mm

l

l

Comments: _______________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________


109


For notes

110



Test Form 5.5 SNR, CNR and AEC repeatability NOTE! 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:

___________________________________________________

AEC Image Stability and Reproducibility and Signal-toNoise Ratio (SNR)

Anode/Filter: ________________________ Exposure No

mAs

SNR

Mean from ROI

kV: _________ Entrance air kerma (mGy)

H/D: _________ SD

CNR

1st 2nd 3rd 4th 5th


111


Anode/Filter

Value


Passed

Failed

≤ 5%

l

l

≤ 5%

l

l

≤ 15%

l

l

≤ 15%

l

l

____________________ Mean value (mAs) SD Dev. (mAs) Coefficient of variation (mAs) Mean value (Entrance air kerma) SD Dev. (Entrance air kerma) Coefficient of variation (Entrance air kerma) Mean value of “Mean” Mean value of SNR Max. deviation “Mean” from Mean value Max. deviation SNR from Mean value

Comments: ________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________

112



Test Form 5.6 Image Quality and Radiation Dose NOTE! 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:

___________________________________________________

Phantom image quality Anode/Filter:

Performance criteria (RMI 156)

Passed

Failed

Fibers

≥5

Speck Groups

≥4

l l

l l

Masses

≥4

l

l

kV: mAs:

Comments: _______________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________


113


Mean Glandular Dose mGy reading from the dose meter AEC mode

kV

Focus

H

Large

D

Large

Anode/Filter

mGy

HVL Values from Test Form 5.7 HVL and Radiation Output

Anode/Filter

kVp

Calculated HVL Values (mm Al)

Compression release Yes

No

l

l

Compression thickness Thickness

Performance criteria 44 ≥ 3 mm

114

Passed

Failed

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*.

PMMA thickness (mm)

Equivalent breast thickness (mm)

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

s-factor

HVL (mm Al)

Mo/Mo

Mo/Rh

W/Rh

1.000

1.017

1.042

* [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 protocol Physics in Medicine and Biology 45, 3225-3240, 2000]


115


Calculate the mean glandular dose AEC mode

Anode/Filter: ________ kV: ________ mAs: ________

D=Kgcs D=Kgcs

Performance criteria Desired (mGy)

Required (mGy)

≤2

≤3

H D

Passed

Failed

l

l

l

l

Comments: ___________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________

116



Test Form 5.7 HVL and Radiation Output NOTE! 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:

___________________________________________________

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

Mo/Mo kVp ______

Mo/Rh kVp ______

W/Rh kVp ______

Exposure reading without Al (D0) Exposure reading 0.2 mm Al Exposure reading 0.3 mm Al Exposure reading 0.4 mm Al Exposure reading 0.5 mm Al Exposure reading 0.6 mm Al Second exposure reading without Al (must not differ more than 2% from D0)

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


117


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

Anode/Filter combination

Calculated HVL Values (mm Al)

Criteria for HVL value at 28 kVp (kVp/100)

Passed

Failed

Mo/Mo

≥ 0.28

l

l

Mo/Rh

≥ 0.28

l

l

W/Rh

≥ 0.28

l

l

Deviation between first and last exposure

≤ 2%

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

Radiation Output mGy reading from the dose meter Anode/ Filter

kV

mAs

Distance above breast support surface (mm)

Mo/Mo

28

400

45

mGy / mR

Sec

mGy/s / mR/s


> 7 mGy/s / > 800 mR/s

Passed

Failed

l

l

Comments: _________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________

118



Test Form 5.8 Tube Voltage Measurement & Reproducibility NOTE! 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:

___________________________________________________

Tube voltage and reproducibility Parameters

kVpmeas


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


kVpmean

Coefficient of variation

119


Parameters

kVpmeas


Passed

Failed

26 kVp

Accuracy: ≤ 5 % kV

l

l

28 kVp


l

l

30 kVp


l

l

32 kVp


l

l

34 kVp


l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

120



Test Form 5.9 Printer Check Printer manufacturer's QC procedure must be followed whenever the printer is used to print mammographic images or accreditation images.

NOTE! 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:

___________________________________________________


121


Printer Check Customer values for Min and Max Density Min Density Max Density

Step

Corr16b-bspline (LUT)

Linear LUT*

Ref. LUT

Maximumdensity

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


Step

122


Maximum density

Minimum density

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*





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


Step






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


123


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.

SMPTE [%]

Step

Measured OD*

Passed

Failed

100

1

l

l

90

2

l

l

80

3

l

l

70

4

l

l

60

5

l

l

50

6

l

l

40

7

l

l

30

8

l

l

20

9

l

l

10

10

l

l

0

11

l

l

* OD = Optical Density

Printer manufacturer required QC manual followed: Compliance

Yes

No

Date _______________

l

l

Date _______________

l

l

Date _______________

l

l

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

124



Test Form 6.1 Ghost Image Evaluation NOTE! 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:

___________________________________________________


125


Ghost Image Evaluation Area

Mean pixel value PV1

PV2

1 2 3 4

Anode/Filter:_________


Passed

Failed

<3%

l

l

kV: _________ mAs: _________ Ghost image factor

Comments: _______________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________

126


© Siemens AG 2007 All rights reserved

Contact Address: Siemens AG Wittelsbacherplatz 2 D-80333 München Germany

Siemens AG, Medical Solutions Special Systems Henkestraße 127 D-91052 Erlangen Germany

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

Siemens MAMMOMAT Novation DR Quality Control Manual

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