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A Medical Physicist`s Guide to Diamond

1. imaging
2. 4 Data Capture 2 16 4 Reference Materials 3 J Integrated Quality Control IQC 16 Il GETTING FAMILIAR WITH DIAMOND A Diamond Operating Controls 4 1 System View 2 Control 3 Positioning Control Centre 4 Foot Pedal Control 5 Other Controls Diamond Set Up 7 Attaching a Cassette Holder Attaching a Compression Paddle Switching On the Inserting a Selecting an Exposure Mode Selecting an X Ray Beam Filter Selecting a Detector Adjusting Density Control Diamond Exposure 9 1 Make an 9 2 Automatic Compression Release 10 3 Display Accuracy amp Brief Specifications 10 4 Post Exposure Display Notes 10 Duty secre es 10 III DESCRIPTION OF MAIN FEATURES A ParkBack terree 11 B Paddlekogies eee 11 C Collimation erre tette renes 11 1 Aperture Plates Diaphragms 2 X Ray F
3. Figure 33 Generator Block Diagram When the operator selects the kV on the control panel Diamond sets a corresponding kV reference voltage in the generator using 8 bit data and a digital to analog converter The generator compares this reference against a feedback signal from the kV in the X ray tube Any error difference between them varies the frequency of the VCO and consequently the switching speed in the H bridge Changes in bridge frequency modulate the power delivered to the high voltage transformer changing the kV in the X ray tube This design quickly compensates for changes in line voltage or load conditions to accurately maintain the kV selected by the operator B DUTY CYCLE The Diamond generator integrates the thermal energy applied to the target kV x mAS Joule with the cooling curves provided by the tube manufacturer Duty cycle limitation is calculated based on the actual target heat load and therefore lasts only as long as necessary to protect the tube During this time an exposure cannot be made If the exposure button is pressed before the cooling time has elapsed the timer display will indicate the cooling time remaining Depending on tube loading technique being used number of exposures and exposure duration the time limit is typically 10 to 50 seconds C GENERATOR SPECIFICATIONS Manufacturer Instrumentarium Imaging Type MGHV 300 Frequency 40 100 kHz Power 2 6 kW kV Range 15 39 k
4. Reproducibility 0 473 0 646 0 430 0 0 598 0 688 0 716 0 729 Figure 32 Finding the Detector With Most Variation Make 8 Auto Time exposures with one based upon each detector The should collect the exposure time and the detector output from each of the 8 detectors for each of the 8 exposures Organize the exposure time and detector output for each exposure for each detector in a spreadsheet see example table Calculate the standard deviation and mean of the output values for each detector Divide the standard deviation by the mean for each detector and multiply by 100 to obtain a reproducibility value for each of the 8 detectors see example table b Review of Statistics Review the 8 calculated reproducibility values and select the largest The largest value corresponds to the detector with the most variation c Verification of Equipment Operation Set the equipment to use only the detector with the most variation Perform routine tests needed to verify accurate setup and operation of the mammography system section 3 a above MM03341b 29 IRSTREUMENTARIUM Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND PHANTOM IMAGING 8 ARTIFACT EVALUATION V PHANTOM IMAGING amp ARTIFACT EVALUATION When imaging the mammography accreditation phantom in Auto kV Mode Diamond usually selects 24 25 or 26 kVp depending on the screen film combination and desired image densit
5. Diamond A Medical Physicist s Guide to the Diamond Breast Imaging System INSTRUMENTARIUM Pimaging MM03341b A Medical Physicist s Guide to the Diamond Breast Imaging System Prepared by Instrumentarium Imaging Inc Instrumentarium gratefully acknowledges contributions to and review of this Guide by Arthur G Haus Consulting Medical Physicist to Instrumentarium and AEC Performance Evaluation Procedure by Melissa C Martin M S FACR Consulting Medical Physicist Member of the FDA Copyright Code MM03341b Date October 2003 2003 Instrumentarium Imaging Inc Authored By Tim Jaenchen Senior Product Specialist Instrumentarium Imaging Inc Documentation trademark and the software are copyrighted with all rights reserved Under the copyright laws the documentation may not be copied photocopied reproduced translated or reduced to any electronic medium or machine readable form in whole or part without the prior written permission of Instrumentarium Imaging Instrumentarium Imaging reserves the right to revise this publication from time to time and to make changes in the content of it without obligation to notify any person of such revision or changes Manufactured By Instrumentarium Imaging P O Box 20 FIN 04301 Tuusula FINLAND Tel 358 10 394 6500 Fax 358 10 394 6501 E mail mammo fi instrumentarium com Internet http www Instrumentariumlmaging com
6. DB 9 Null Modem Adaptor if collecting the COM 2 label output 3 HyperTerminal Interface For Diamond The HyperTerminal interface and setup may vary somewhat depending on the version of the program and operating system however its setup should be similar to the information offered here Figure 20 Connect To Dialog Figure 19 Port Settings Dialog MM03341b 15 A MEDICAL PHYSICIST S GUIDE TO DIAMOND P imaging DESCRIPTION OF MAIN FEATURES a b In HyperTerminal select the desired COM port with the File Properties menu and the Connect To tab sheet Next click Configure to open the Port Settings dialog box Adjust the parameters to those shown in the table below Accept the changes with OK The serial connection is an ordinary asynchronous receiver transmitter RS 232 The serial ports in Diamond are initialized as follows Baud Data Stop Flow Port Rate Bits Parity Bits Control COM 1 19200 8 None 1 None aecdump COM 2 1200 8 None 2 None Alpha ID Table 6 Serial Port Configuration 4 Data Capture a b With Diamond switched off connect the serial cable between COM 1 and the PC serial port see back panel connections in the appendix OR For COM 2 output remove the serial cable from the Alpha ID Il and connect it with the null modem adaptor to the PC serial port On the PC using Notepad or a similar text
7. 0 15 OD DETECTOR pri C2 CONFIG sec Bu RH MODE sec A mAS TEST OBJECT 4 cm LIMIT 0 3 OD LIMIT 0 15 OD 0 3 OD 0 3 OD DETECTOR pri C2 CONFIG quat Mg RH MODE sec A mAS TEST OBJECT 4 cm LIMIT 0 3 OD DETECTOR pri C2 CONFIG ter Mg MO MODE sec A mAS TEST OBJECT 4 cm LIMIT 0 3 OD DETECTOR pri C2 CONFIG quat Mg RH MODE pri A kV TEST OBJECT 4 cm LIMIT 0 3 OD DETECTOR pri C2 CONFIG ter Mg MO MODE pri A kV TEST OBJECT 4 cm LIMIT 0 3 OD Figure 30 Diamond AEC Evaluation Method No 2 3 Testing Procedure MQSA Method 2 The various combinations of Configuration Mode and Detector are illustrated in the figure Diamond AEC Evaluation Method No 2 The expression method No 2 refers to the MQSA 26 MM03341b P imaging recommendation for evaluating AEC systems with multiple modes and detectors reference MQSA PGHS 6 pg8 Question 4 a Setup Diamond Prepare the unit with the Primary Configuration and Mode Auto kV De select AutoPoint press AutoPoint button LED off and select the primary Detector C2 This setup is expressed as the contact configuration by MQSA A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM b Perform Test Exposures Use a uniform attenuator of 2 4 and 6 cm thickness
8. Diamond complies with UL and C UL File E218408 North American Distribution Instrumentarium Imaging Inc 300 W Edgerton Avenue Milwaukee WI 53207 Tel 800 558 6120 Fax 414 481 8665 E mail info usa instrumentarium com Internet http usa instrumentarium com Windows is trademark of Microsoft Corporation in the United States of America and other countries HyperTerminal is a trademark of Hilgraeve Inc Monroe MI USA A MEDICAL PHYSICIST S GUIDE TO THE DIAMOND BREAST IMAGING SYSTEM TABLE OF CONTENTS 4 Grid Specifications TAN INTRODUCTION TO DIAMOND G MultiChoice A 1 Physicist Test B 5 1 1 Using the Service Mode Interface 1 Intended itte 2 Service Program Menu 2 Radiation Safety 3 Using the Physicist Mode Program Safety Features amp Error Codes Collecting Data Using an External PC C Other Sources Of Information 1 Data 1 On Site OEM Documentation 2 2 Equipment 2 Contact Information 3 HyperTerminal Interface For Diamond 15 3 Calling For
9. 2 Attaching a Compression Paddle Insert the compression paddle into the holes on the front of the Positioning Control Centre and push the paddle horizontally until it locks MM03341b 7 ee Imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND 2 To remove a compression paddle first push and release either of the two 4 release buttons not both located on each side of the Positioning n Control Centre to unlock it Then remove the paddle by pulling it Li out horizontally 4 3 Switching On the Unit Check that the power cord is connected and the circuit breaker see 01 is switched Toggle the Diamond user power switch to ON behind the carriage left side patient view During initialization the control panel displays the software version i e Diamond SW C1 02 7 afterwhich it displays Timer 0 kV 25 MAS Density 0 0 Auto kV on filter Note this start up condition is the default and may have been modified by the installer Figure 9 Attaching a Compression Paddle 4 Inserting a Cassette Figure 10 Inserting a Cassette 1 Push the cassette latch aside with the leading corner of the cassette 2 Continue to insert the cassette holding it level and square with the Bucky 3 Gently slide the cassette in until the latch springs back into place Take care not to trap your fingers The
10. 4mAS for mAS s 40 10 for mAS gt 40 large focus 0 02 5 0 Sec Ti R small focus 0 04 10 Sec Timer Accuracy 0 10 seconds Compression Force Display 20 N Compression Thickness Display 1 cm Angle Display 2 mGy Display 30 Table 2 Brief List of Specifications 4 Post Exposure Display Notes kV_Display If Auto kV mode was used the value in the kV display reflects the final kV selected not necessarily the initial or intermediate kV at the beginning of an exposure sequence See AEC Function Description for more information about kV shifting Timer Display If a Bucky device was used the value in the Timer display reflects the net exposure time which accounts for the off time introduced by the Synchro Bucky feature See ProForm Synchro Bucky for more information NOTE Triggering and timer accuracy of non invasive kVp Meters may be affected by Diamond s Synchro Bucky feature 5 Duty Cycle Duty cycle limitation is calculated based on the actual target heat load and therefore lasts only as long as necessary to protect the tube During this time an exposure cannot be made If the exposure button is pressed before the cooling time has elapsed the timer display will indicate the cooling time remaining typically 10 to 50 seconds See the Diamond X Ray Tube section for more information 1 For further information ab
11. in the image receptor base This unique circuit contains 8 discrete detector arrays that are optimized in size shape and location 4 of them are positioned on the cassette centerline four of them are off centerline A detector location is selected not by mechanical movement but rather by software activation either automatically by AutoPoint or manually by the operator AutoPoint selects the most appropriate detector to use for calculating the exposure time and yields benefits such as Fewer retakes from choosing the wrong detector 4 Consistent selection of a detector based on 2 object radio opacity not on visual appearance homogeneous optical densities over the 3 entire breast image More reliable performance when small breasts 2 e examined detectors are elliptical in shape 3 along the centerline a adm 2 are angled next to the centerline and 3 half ellipses are at L R the chestwall edge The active area of each detector array is sampled by a minimum of 12 sub detectors B MODES OF OPERATION NOTE For all three Modes of Operation both the focal spot selection and tube current mA are managed by Diamond and not adjustable by the operator 18 MM03341b 1 A traditional exposure control system in which the operator selects the technique kV and the exposure time mAS The following mAS values may
12. 0 Coefficient 85 vDspl dec 24 IntTime dec 104 ActExpTime dec 292 Thickness dec 210 Filtered xraylevel dtr_xray 0 dec 2198 Filtered xraylevel dtr_xray 1 dec 2448 Filtered xraylevel dtr_xray 2 dec 2406 Filtered xraylevel dtr_xray 3 dec 2541 Filtered xraylevel dtr_xray 4 dec 2290 Filtered xraylevel dtr_xray 5 dec 2689 Filtered xraylevel dtr_xray 6 dec 2910 Filtered xraylevel dtr_xray 7 dec 2687 eke 1936 Figure 36 Data Output param aecdump 1 B Mo 1 40s 23kV 126mAs 1 3 5cm 050N 000 L 1 69mGy C2 01939 B Mo 0 56s 27kV 050mAs 2 21cm 000N 000 L 0 56mGy C4 01940 Figure 37 Data Output exposure flash label MM03341b 45 DC1 02 7 param aecdump 2 aecdump 2DC1 02 7 gt Exp Nr 1935 15 01 Preprog 1 Detectors 4 0 Coefficient 85 RotPoint dec 80 RotL dec 104 RotR dec 98 SlopeL dec 250 SLOPER DEC 250 ThComp dec 105 KvDspl dec 24 KvComp dec 100 IntTime dec 104 ActExpTime dec 292 Thickness dec 210 Filtered xraylevel dtr_xray 0 dec 2202 Filtered xraylevel dtr_xray 1 dec 2442 Filtered xraylevel dtr_xray 2 dec 2413 Filtered xraylevel dtr_xray 3 dec 2542 Filtered xraylevel dtr_xray 4 dec 2293 Filtered xraylevel dtr_xray 5 dec 2678 Filtered xraylevel dtr_xray 6 2912 Filtered xray
13. 113SP Data Sheets may be found in the client s Operating Instructions Manual Section 12 Insert Model M 113SP Housing Model B 112 Maximum Peak Voltage 39 kV Anode to Ground Nominal Focal Spot Size Small 0 1 mm Large 0 3 mm Anode Material Molybdenum Niobium doped Anode Angle Bi Angle Large 16 Small 10 Anode Diameter 77 mm Anode Heat Storage 300 kHU Maximum Anode Cooling Rate 60 000 HU minute 0 mm AL equiv For operation to 39 kV 0 5mm AL min must be added Molybdenum 0 025 mm Added Filtration Rhodium 0 025 mm Aluminum 0 50 mm Inherent Filtration Window Material 0 76 mm Beryllium 40 MM0334 1b INSTRUMENTARIUM 0 Imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX U L Approved Yes B 112 Housing Class Type Maximum Peak Voltage 52 kV common cathode Housing Heat Storage Capacity 370 KJ 500 kHU Housing Cooling Rate 100 Watts 135HU sec Focal Spot Port Spacing Small 47 0mm 1mm Large 41 4 1mm Acoustic noise 50dB Max A weighted at 30 cm Leakage Technique Factor M113SP 52 kV 2mA Leakage Technique Factor B112 55 kV 4mA Stray radiation complies with the Rayproofing requirements of 21 CFR Subchapter J for medical diagnostic type protective X ray tube housings Focal spot measurement method M1
14. A Operating Principles 32 2 20 32 C Generator Specifications 32 VIII COMPRESSION SYSTEM As Foot Controls ccs era ci b rera 34 B Compression 34 C ECS Compression 34 IX APPENDIX A Article One Physics Testing Procedures for 35 Article Two AEC Density Control Performance Clarification 37 C Template Detector 39 vi D Table Maximum 40 E Varian X Ray Tube Specifications 40 F Alpha ID Flash Label Explanation 41 G Table Diamond Error Code Guide 41 H Back Panel Connections 44 Data Output 45 1 IA TRUE TAR Bimaging a A MEDICAL PHYSICIST S GUIDE TO DIAMOND AN INTRODUCTION TO DIAMOND 1 AN INTRODUCTION TO DIAMOND screening and diagnostic mammography examinations and interventional procedures Among its many remarkable features are several new and innovative ones which include AutoPoint AEC Detector ParkBack tube head movement PaddleLogic ACR motorized C Arm rotation and the Position Control Center Additionally Diamond
15. AutoPoint off and then pressing the relevant detector button on the Detector Location Display The detector outline on the compression paddle correlates with the detector buttons and their location under the image receiver Find more AutoPoint Mo Rho Al Fig 13 Filter Selector Figure 14 Detector Selector information in the AEC Features and AEC Operation sections later on in this document 8 Adjusting Density Control Each AEC mode has 15 steps for density adjustment where one step corresponds to a 10 change in mAS factory default Since the step size may be programmed from 5 to 20 by the installer consult with the client to verify if a special adjustment was made More information on the Density Control may be found later on in this document C DIAMOND EXPOSURE 1 Make an Exposure The Ready light illuminates when Diamond is prepared for an exposure If the exposure button is pressed before the system is ready a message is displayed to the operator indicating the reason why not Make an exposure by pressing the X Ray Exposure Control a single stage switch no prep position and continue holding Radiation production is made known to the operator by the illuminated X Ray terminates Den Figure 15 Density Selector ready x ray ae 4 Figure 16 Ready X Ray Indicators it until the X ray exposure light the audible e
16. FAMILIAR WITH DIAMOND A DIAMOND OPERATING CONTROLS 1 System View ParkBack Tubehead Compression Paddle Synchro Bucky cassette holder Cassette Load Eject Position Control Centre Paddle Release Ratate Control Vertical Control Manual Compression StereoTactic Tilt ParkBack Control Pre Program Angle Emergency Stop Power On Off Circuit Breaker Qzzrmxmerrgpmmuorcuis Figure 7 Diamond Main View 4 MM03341b INSTRUMENTARIUM imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND 2 Control Panel INSTRUMENTARIUM imaging Ready Indicator Exposure Time Display green LED ready ES iia timer Radiation Indicator x ray amber LED KV Selector range 20 39 step 1kV MAS Selector MAS Display range 2 500 Density Selector range 7 to 7 Avg Glandular Dose Display AEC Mode Selector AutoKV AutoTime Manual Filter Indicator 3 green LEDs mGy Filter Selector moly rhodium aluminum Auto AutoPoint Indicator Point green LED AEC Mode Indicator _ Warning This x ray unit may be dangerous to 3 green LEDs operator unless safe exposure factors and operating instructions Menu Selector 8 Set Button for menu options Cancel Button for menu options Function Key 3 button LED and LCD label LCD Display Function Key 1 button LED and LCD label Function Ke
17. Guidance Help System PGHS Document No 6 Aug 19 2003 a Detector Balancing The Diamond AEC system is designed with a software gain control parameter that is adjusted during the calibration process This control varies the detector signal strength after the detector selection MUX i e in the signal path common to all detectors and allows the service provider to calibrate Diamond to the desired film optical density In addition to this master gain control there are 8 more software parameters used by AutoPoint to adjust the gain of each detector individually The process of setting these individual gain controls is known as Detector Balancing 23 A MEDICAL PHYSICIST S GUIDE TO DIAMOND Imaging AUTOMATIC EXPOSURE CONTROL SYSTEM Mammography films often demonstrate an optical density gradient that decreases as one scans toward the anterior edge see figure Heel Affect a characteristic common to X ray tubes causes this symptom Manual Technique 25kV 100mAS 25kV 125mAS Optical density measurements from two 25 kV exposure at manual techniques of 100 mAS black upper values and 125 mAS red lower values The O D gradient varies about 2096 to 25 between detector C1 to C4 Figure 28 Optical Density Gradient As an example the AEC was calibrated to achieve the desired film OD of 1 80 1 90 Noticed that if C4 were selected user or AutoPoint the
18. contrast screen film mammography system processed according to the film manufacturer s specifications The film contrast is approximately 3 0 at an optical density of 1 0 This differs from the maximum film contrast of approximately 4 5 at an optical density of 1 7 If the Density Control changes the mAS by a consistent percentage say 10 in the case of the Performa it is performing correctly The change in optical density seen on film will be less in the lower density regions where the film contrast is lower For the same Density Control step change in mAS the change in film optical density will be highest near the peak film contrast of 1 7 in this example and lower above the peak value 1 This article was originally written for the Medical Physicist s Guide for the Performa In principle however it applies to the Diamond system as well 2 The step size of the Diamond Density Control can be programmed by the installer from 5 20 change in exposure time or mAS MM03341b 37 A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX Gamma Plot D Log E 4 00 5 00 3 00 _ 4 00 3 00 8 45 E E 200 2 z 1 00 9 100 0 00 5 9 9 lt 0 05 1 L5 2 25 3 35 4 9200 l 1 1 1 5 15 21 Average Sensitometer Density Step Number Figure 1 Gamma Plot and H amp D curve showing change in film contrast with density Recommendations As long as the mAS changes by approximately 10 with each step change
19. density in the area of C4 is an acceptable 1 81 OD but the density in the area of C1 might be as high as 2 24 OD So the main challenge in balancing the detectors is to address the question Should the optical density for each of the detector s local area equal the desired film OD or should a fixed location area equal the desired OD b Local Area Method With this method the detector gain is adjusted for each of the 8 detectors so that the film OD in the location of that detector i e the local optical density will be the desired film OD Yields accurate film OD inside the local area Gives a logical result i e the user expects the local area to be the desired OD The film OD can change dramatically outside the local area The image quality might be diminished from too high an OD outside the local area The AEC system might perform unexpectedly For example if C4 is selected 13 cm anterior to the chest wall edge to provide the dose necessary to compensate for heel affect the system must increase either the exposure time or beam energy kV possibly beyond what the user expects or desires 24 MM03341b 1 IRSTRUMENTARIUA Bimaging XE MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM c Common Area Method The detector gain is adjusted for each of the 8 detectors so that the film OD at a common location such as C2 will be the desired film OD The heel affect gr
20. in Density Control the unit is functioning according to its specifications Recall that the ACR Mammography Quality Control Manual recommends the mAS change or the optical density change per step change in Density Control It may be helpful to include a brief explanation of this fact in your report such as The Density Control on your unit is functioning within Instrumentarium specifications No further action is required on your part Density Control is not specified in MQSA and is not evaluated during MQSA inspections The ACR Mammography QC Manual contains recommendations for Density Control performance Your unit meets the recommendations for mAS but exceeds the recommended change in optical density for some steps due to the very high and clinically desirable film contrast of your system For your information the table shows how the optical density changes for each Density Control step on your unit Density Control mAS OD Density Difference 5 39 0 80 0 11 4 43 0 91 0 16 3 47 1 07 0 10 2 51 1 17 0 15 1 57 1 32 0 18 0 63 1 50 1 68 1 71 0 21 2 76 1 91 0 20 3 84 2 11 0 20 4 93 2 33 0 22 5 104 2 51 0 18 38 MM03341b APPENDIX a a o o o o x a l lt lt 8002 V Aoueipdsupi euin o 10129Jog puouubpig 001978557008 VSN LOZES IM uou
21. signal deviation unique to that signal path This not only results in a variation from one exposure to the next but also from one detector to another To fully assess the AEC hardware a complete series of test exposure should be performed for each detector circuit When one considers the variety of tests that might be performed reproducibility kV linearity thickness linearity and then also considers repeating those tests for up to 8 separate detectors it becomes a concern for the regulatory community the manufacturer and especially for the healthcare provider b Diamond Multi Detector Design Each detector array generates a leakage current proportional to the incident radiation The current signal is amplified by a dedicated 1 per detector current to voltage converter then sent and to a common Detector Selection multiplexer Under microprocessor control the multiplexer sequentially streams the 8 signals to a common output From the MUX output to all subsequent electronic circuitry ALL detector signals share a common path to the microprocessor and the exposure time algorithm in software In other words any inconsistency among the detectors can only be introduced prior to the multiplexer 22 MM03341b P imaging YING A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM Diamond software has a service inspection feature that allows the service provider or Medical Physicist to directly examine detector b
22. the X ray field size will be limited to 18 cm by 24 cm The smaller field size for any paddle or receiver combination prevails over the larger Table 4 Physicist Mode Adjustments 3 Using the Physicist Mode Program 8 Start Service Mode as described in step 1 above b Access the Service Program Menu by pressing the Menu Set button The LCD display shows a portion of the list of Groups Function Key 1 Fkey1 scrolls the list Down while FKey3 scrolls Up C Press Up or Down until the L Physicist Group is displayed between the pointers gt lt Press Accept FKey2 to gain access to the program d Within the L Physicist group is a single Procedure item called 1 Setup Press Accept to open it e Step down through the list of Parameters by pressing Next until the desired item is between the pointers note that navigation has shifted to FKey2 Change the parameter value with the Down or Up keys according to the table above Press Menu Set to approve the change f Press Cancel at any time to exit without making a change press it several times to return to Service Mode NOTE Any changes to settings made in the Physicist Mode Program are restored to normal System defaults when exiting Service Mode 14 MM03341b Menu INSTRUMENTARIUM Imaging 5 A MEDICAL PHYSICIST S GUIDE TO DIAMOND DESCRIPTION OF MAIN FEATURES COLLECTING DATA USING AN EXTERNAL PC Diam
23. the film Each detector channel can be programmed with its own software gain and offset calibration control providing a great deal of flexibility in calibrating and balancing the detection hardware The hardware is all solid state with no trim potentiometers all adjustments are made in software controlled multiple detector design gives the installer and operator many options in its calibration and use The AutoPoint Detector has two modes of operation automatic and manual In the automatic mode AutoPoint selects the 2 most appropriate detectors primary and secondary Ma by rapidly scanning all 8 signals at the very onset of radiation It is looking for those with the lowest signal strength because their output represents the areas of greatest absorption in the patient When AutoPoint finds the proper detectors it passes that data to the software algorithm for exposure time calculation In manual mode the operator selects which E detector the system is to use T The user selects the mode of operation at the Position Control Center If AutoPoint mode is selected the AutoPoint LED lights up at the Positioning Control Center and on the Control Panel When the AutoPoint LED is off the detector is selected manually The user can choose Figure 25 Position Control Centre 21 P imaging the desired detector by pressing one of the selection buttons an LED lights to indicate the active detecto
24. the paddle stationary against the patient This bi lateral action results in very affect application of compression motion and force against the mobile margin of the breast REL The compression paddle is driven away from the cassette holder and the C Arm is shifted in the direction of the cassette holder relieving compression force Until the C Arm reaches its travel limit its speed is synchronized with the paddle a stationary paddle Z UP The Carriage is driven vertically upward until a limit switch is activated Its operation is dual speed starting at a slow speed and after 1 second switching to a high speed Z DOWN The Carriage is driven vertically downward until a limit switch is activated B COMPRESSION FORCE Pressure against the patient is measured with a strain gauge in the compression mechanism and updated to the digital display The compression system micro controller compares this pressure against a pre selection key setting from the operator 1 46 programmable by a service technician and stops motor drive when they match Maximum force 6 is programmable from 80N 18106 to a maximum of 200N 45156 The manual compression wheels allow manual decrease or increase of compression force The wheels are located on either side of the Position Control Centre The operator may increase the force up to 300 N 66 Ibs Manual compression release is possible without power to the unit using the hand whee
25. uniform thickness phantom Action Limit The AEC shall be capable of maintaining film optical density within 0 15 of the mean when the thickness of the phantom is varied over 2 6 cm and the kvp is varied over the range of those used clinically for those thicknesses As shown this Diamond unit will meet or exceed those requirements for density uniformity specified by both MQSA and the ACR Standards for Mammography Equipment Performance These procedures were discussed and approved at the April 28 2003 meeting of the National Mammography Quality Assurance Advisory Committee to the FDA Physicists on this committee are Andrew Karellas Ph D and myself As a consulting physicist a concise method of meeting these test requirements was of utmost importance without compromising our commitment to our clients to thoroughly evaluate their new equipment Any comments or further suggestions are welcome Melissa C Martin M S FACR President Therapy Physics Inc MelissaMartin Compuserve com 36 MM03341b 1 ATRL RATA Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX B ARTICLE TWO AEC DENSITY CONTROL PERFORMANCE CLARIFICATION Robert J Pizzutiello Jr M S FACMP July 20 1999 Question When testing the AEC on a Performa what should be done if the change in mAS is consistent with the recommendations in the 1999 ACR Mammography Quality Control Manual but the optical density change differs from what 1s stat
26. 13SP small focus Measured at 25kV 20mA with one degree star pattern or a slit focal Maximum focal spot size 0 15W x 0 15L mm M113SP large focus Measured at 25kV 80mA with one degree star pattern or a slit focal Maximum focal spot size 0 45W x 0 58L mm Table 9 Varian X Ray Tube Specifications F ALPHA ID FLASH LABEL EXPLANATION Patient Name __ Patient ID Facility Address od Patient Age VEN SUUS 74 Facility Address n 9 23 cb Patient D O B 1244 MAIN STREET 53562 Room 1 1 0 Tech Initials D4 24 04 08 48 C3 0 000 RCC Date amp Time Wie ERE E Filter detector density ku time 2 correction angle dose thickness cassette holder view force Figure 34 Alpha ID 1 Field Definitions G TABLE DIAMOND ERROR CODE GUIDE Error Code Reason for Error Corrective Action Er0002 Program check sum error flash Call service Program check sum error BattRAM Check if exposure button cable is properly connected Er0003 Check physical condition of the cable any broken strands etc Er0011 Emergency button activated pressed down Release emergency button Er0012 Tube Park safety clutch acts tube obstacle Clear and try again If problem persists call service MM03341b 41 A MEDICAL PHYSICIST S GU
27. AutoDrive operation can be programmed to automatically drive forward when the exposure control is pressed before exposure prep begins If the exposure control is released prematurely the forward movement stops AutoDrive is inhibited if the paddle or cassette holder is missing or if biopsy paddles or the Delta 32 receiver are in use NOTE Pressing any button will stop all motor operation affecting patient safety B PADDLELOGIC Diamond s PaddleLogic feature facilitates 1 automatic adjustment of the collimator and 2 regulation of AutoPoint AEC detectors separately for each compression paddle This feature can be customized to customer preferences and is especially useful for diagnostic imaging such as spot compression views or interventional procedures when using biopsy compression paddles When Diamond detects one of these special paddles it automatically collimates the X ray beam to the region of interest and constrains the available detectors to that same ROI The factory default is set for full coverage of the receiver for all paddles NOTE If the paddle and the cassette holder suggest different X ray field sizes Diamond will always select the smaller field size C COLLIMATION Diamond has a fully computerized Beam Limiting Device collimator The radiation field size is automatically collimated when Diamond determines which cassette holder Bucky or Multi Magnification and compression
28. Diamond includes a set of uniform acrylic test objects 18cm x 28cm in 0 5 1 0 and 2 0 cm thickness Ask your client for their location c Measure and Record Film OD For each test object assess the film OD at the center of Detector C2 and complete the table below HINT Place the film on the compression paddle to quickly determine the location of C2 DETECTOR C2 CONFIG Bucky Mo MODE Auto kV Test Object cm Film OD at C2 1 2 0 2 4 0 3 6 0 4 8 0 opt d Determine the Mean Optical Density MOD Calculate the average film OD from the density values above and record below Note MQSA does not recognize the 8 cm value in the MOD calculation MEAN OPTICAL DENSITY MOD e Confirm AEC Performance for Primary Detector Configuration and Mode Confirm that the test results for the primary configuration mode and detector used above meet the regulatory action limit of 0 15 OD MOD HIGH LOW Film OD Deviation from MOD f Confirm AEC Performance for Other Configurations and Modes Assess all other Configurations and Modes used at the facility MQSA requires that all other results equal the MOD within the regulatory action limit of 0 3 OD at any ONE clinically used thickness in the 2 6 cm range 4 cm is recommended Vary the Configuration and Mode according to the table below Measure and record the film OD and determine the deviat
29. GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM b Mode The method for controlling exposure timing Diamond has three control methods Manual and two automatic modes Auto kV and Auto Time Auto kV is considered the primary mode because it is used most often c Detector The electronic sensor diode array that responds to EM radiation Diamond has eight discrete detector arrays Detector C2 is considered the primary detector since it is the most centrally located most clinically relevant one d Other Mode A customized setting of the Mode Diamond incorporates 4 pre programmed modes stations that permit a personalized setup for the user such as main or back up film processor Dr A or Dr Figure 29 Primary Detector B etc Normally these are not used therefore only one station needs to be tested consult with your client or the installer DET 63 DET C4 DET L2 DETECTOR pri C2 CONFIG pri Bu MO MODE sec A mAS DET L1 TEST OBJECT 4 LIMIT 0 3 OD 0 3 OD mod DETECTOR pri C2 CONFIG sec Bu RH MODE pri A kV TEST OBJECT 4 cm LIMIT 0 3 OD 0 15 OD Mean Optical Density MOD 0 3 OD DETECTOR primary C2 CONFIG primary Bu MO DETECTOR C1 MODE primary A kV CONFIG pri Bu MO TEST OBJECT 2 4 6 8 cm MODE pri TEST OBJECT 4 LIMIT
30. HYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND AEC Operating Range kV Limits Manual 20 39 kV Bucky Specimen 15 39 kV Auto Time and Auto kV 23 35 kV Manual 20 39 kV Magnification Specimen 15 39 kV Auto Time and Auto kV 23 35 kV Manual 20 39 kV Specimen 15 39 kV Delta 32 Table 1 KV Limits in AEC 6 Selecting an X Ray Beam Filter Diamond has three X ray beam filters Molybdenum Mo Rhodium Rh and Aluminum AP filter is selected with the button at the Position Control Centre The movement is motorized and the chosen filter is indicated with an LED Diamond can be configured to automatically select the most appropriate X Ray beam filter Auto kV and Auto Time modes by enabling the AutoFilter feature manual control is the default setting Mo and Rh filters are available between 15 35 kV all modes Al between 36 39 kV in manual mode only More Diamond X ray Tube information may be found later on in or on the Control Panel this document 7 Selecting a Detector Diamond s AEC system has 8 detectors that can be selected automatically or manually In automatic mode AutoPoint LED on it chooses the most appropriate detector at each exposure depending upon the individual breast being examined Toggle automatic mode on off by pressing the AutoPoint button on the Detector Location Display Select a detector manually by first toggling
31. IDE TO DIAMOND imaging 0 APPENDIX Error Code Reason for Error Corrective Action Er0013 Tube movement back up time reached Check for any visible obstacles for tube movement Er0014 Filter movement back up time reached Change another filter If problem persists call service Er0015 Collimator plate movement back up time Clear and try again If problem persists call service reached Er0022 Compression motor back up time reached Clear and try again If problem persists call service Meanwhile compress manually Clear and try again If problem persists call service Er0023 COMPRESSION THICKNESS MEASUREMENT ERROR Er0024 Compression force measurement failure If problem persists call service Compress manually Inhibit compression down Er0027 Overflow in Auto Time or Auto kV mode kV too low Try with higher kV values Er0029 Underflow in Auto Time or Auto kV mode kV too high Try with lower kV values Er0033 Cassette tray back up time reached Clear and try again If problem persists call service y y ag Er0034 Cassette not changed Change cassette Try also with another cassette Er0035 Cassette opto sensor failure Check cassette opto sensors Reduce lightning in Bucky area Er0037 Grid error during prior to exposure Displayed Re attach Bucky Try also with another Bucky after exposure if expo
32. Initial Comparison of All Detectors Install a 40 mm acrylic test block Set the machine at 28 kV and AutoTime Connect a PC running a data communication program i e Windows HyperTerminal or equiv to the Diamond RS 232 serial comm port Use the command param aecdump 1 Exp Nr 649 14 19 Preprog 1 Detector hex 0001 KvDspl dec 28 IntTime dec 118 ActExpTime dec 445 Thickness dec 40 Filtered xraylevel dtr_xray 0 dec 1918 Filtered xraylevel dtr_xray 1 dec 2002 Filtered xraylevel dtr_xray 2 1895 Filtered xraylevel dtr_xray 3 dec 1893 Filtered xraylevel dtr_xray 4 dec 1658 Filtered xraylevel dtr_xray 5 1772 Filtered xraylevel dtr_xray 6 dec 2026 Filtered xraylevel dtr_xray 7 dec 1853 Nr 649 Figure 31 Sample Printout param aecdump 28 MM03341b 1 VAT ERR IPLE CIC LEE EEUU PE Bimaging XE MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM Example of Test to Determine Detector with Most Variation Poorest Reproducibility Diamond AEC Evaluation C INSTRUMENTARIUM IMAGING 2002 40 mm Acrylic 28kV Mode Auto mAS Detector Signals Standard Deviation 8 991 12 829 8 137 10 025 12 271 14 322 13 501 1899 6 1985 0 1892 8 1677 3 1783 5 2000 6 1852 4
33. Specifications Standard Grid R O C Grid Bucky Equiv lt 25 um total of all layers lt 25 um Al total of all layers Grid Frequency 36 Ip mm 36 Ip mm Grid Ratio 5 1 6 1 equivalent Table 3 Grid Specifications G MULTICHOICE MAGNIFICATION For magnification studies Diamond users may conveniently choose from one of three magnification ratios using the same cassette holder film format is 18 x 24 cm The factors are 1 6x 1 8x and 2 0x and are easily changed by the operator The magnification factor is indicated in a window and can be changed by pushing in the two small knobs in the back of the tunnel frame and then lifting up or lowering the tunnel The small focus 0 1mm is automatically selected for magnification exposures In magnification manual mode kV values starting from 20 kV can be used H PHYSICIST TEST MODE When it is operated in Normal Mode Diamond automates many functions and processes for easier and safer operation For example functions such as focal spot selection or beam collimation are automatic and not adjustable by the routine user Or processes like cassette insertion or kV selection are monitored and controlled to prevent wrong exposures However during an annual inspection by a Medical Physicist or calibration by a service technician these automated actions tend to make certain tasks more time consuming or even impossible Diamond software incl
34. URES 1 Absolute AEC Absolute AEC combines the technologies of Total Exposure Control TEC which originated with Instrumentarium s Performa Mammography System together with the brand new AutoPoint technology Auto Technique Parameters are selected during the exposure which means no test exposure is necessary Exposure Monitor terminates the exposure in 50 msec if proper image density cannot be achieved within the backup time unnecessary patient dose is minimized 2 PaddleLogic Diamond PaddleLogic feature recognizes the compression paddle being used and auto matically adjusts the collimation and regulates the detectors available for AutoPoint Interventional or special procedure paddles like spot compression devices or small biopsy paddles can be individually configured to collimate radiation exposure only to the region of interest and constrain the AutoPoint detector to that same ROI 3 Density Control The density control function is a microprocessor based feature that manipulates the AEC exposure time calculation On the operator control panel is a 15 step density selector ranging from 7 steps to 7 steps The amount of change in exposure time per step is programmable by a service technician between 5 and 20 in 1 increments An article discussing Density Control Performance may be found in the appendix 4 AutoPoint Detector The AutoPoint Detector is a highly complex component of the Diamond AEC system located
35. V in 1 kV increments kV Accuracy 1 5 kV kV Ripple lt 5 large focus 50 100 mA or 25 50 small focus 18 30 mA mA Range Maximum mA Output large focus 150mA 32 MM03341b IVSIERLUMHENTARIUM imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND THF X RAY GENERATOR small focus 45mA large focus 2 500 mAS small focus 4 300 mAS mAS Tolerance mAS lt 40 4 mAS mAS gt 40 10 mAS Range large focus 0 02 5 seconds Time R 2 small focus 0 04 10 seconds Timer Tolerance 0 10 instrument inaccuracy Exposure Time The interval between the beginning and ending points of the high voltage as measured by a calibrated x ray monitor at 7096 of the peak radiation waveform kV The high voltage mean value received after measurement with a calibrated x ray monitor mAS The resistance value divided by voltage A calibrated x ray monitor measures the voltage over feedback resistor and provides a mAS value Nominal X ray tube voltage 39kV is obtained at highest tube current 50mA The highest tube current 100mA is obtained at tube voltage 25kV The highest electric power is obtained both at 32kV 80mA and at 25kV 100mA nominal electric power of 2 4 kW is obtained when loading time is 0 15 and x ray tube voltage 30kV is used Low mA Mode optional configuration tha
36. adient will influence the local area film OD even though the common area film OD is consistent The AEC system will yield a performance response that is more in keeping with user expectations less dramatic kV shifting for example Smaller chance that the film OD at the chest wall edge is unacceptably high Smaller deviation in film OD between views and patients Example if for patient A detector C4 is selected the film density at the common area will be the same as for patient B where detector C1 is selected Feedback from medical physicists and the inspection community indicate a preference for testing with a Local Area method because it is more in accordance with the testing procedures and performance expectation i e 0 15 MOD of the MQSA and ACR Quality Control Manual However from radiologist and technologist feedback and installer experience it seems that a majority of cases when the AEC system is calibrated with Common Area detector balancing the overall film OD image contrast and exposure technique at a given facility is more stable and more compliant with the performance capabilities of traditional AEC systems and the expectations of the mammography community Instrumentarium has established an alternate method It is based primarily on the local area method each detector produces a local OD that is 0 15 MOD However to prevent excessive film OD at the chest edge in those cases w
37. all service Er0060 Exposure button released during exposure Load new film and expose Hold exposure button down until the audio signal ends Er0062 Generator failure kV not OK Clear and try again If problem persists call service ag Line voltage low Have an electrician check the voltage of the electric Er0063 outlet If it is strong and stable enough then call service for further actions 42 MM0334 1b 0 imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX EE Reason for Error Corrective Action Code Er0064 Cassette missing Insert a cassette and try also with another type Er0065 Exposure time exceeds limit too long too Increase decrease kV values and try again If problem short persists call service Movement button or switch exposure button Clear and try again If problem persists call service 0066 pressed during movement or start up function not allowed Er0067 Device not ready for exposure Clear and try again If problem persists call service 0068 Delta 32 PC refused to receive exposure Clear and try again If problem persists call service Er0069 Delta 32 PC connection time out Clear and try again If problem persists call service Er0070 Error in stereo motor pulse measuring Clear and try again If problem persists call service Tube head heat limit exceede
38. analysis at 23 kVp using any rhodium filter on any x ray unit Non uniformities will very often be visible on test films but not visible on clinical images at clinical kVp values Not all artifacts can be totally eliminated The concept of ALARA as low as reasonably achievable may be useful To determine if artifacts are clinically significant compare artifact test films with those from other machines and consult with the interpreting physician as to whether the artifact is tolerable If unsure seek the opinions of more experienced medical physicists to determine if the artifacts observed may interfere with clinical imaging Replacing the filter or other source of artifacts should eliminate any artifacts that may compromise clinical imaging 30 MM0334 1b P imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND DIAMOND X RAY TUBE VI DIAMOND X RAY TUBE Diamond utilizes an X Ray tube manufactured by Varian Medical Systems which is intended for use in mammography systems It contains the proprietary model M 113SP rotating anode 39 kVp insert with a dual focal spot metal center section common cathode design The use of arcing due to metal deposition on glass and allows use Additional X Ray tube a metal center section tube eliminates of a beryllium window in the insert for minimum inherent filtration specifications may be found in the appendix A TARGET AND FILTER INFORMATION Anode Material Molybdenum Niobium doped I
39. be selected A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM 2 3 4 5 6 8 10 12 16 20 25 32 40 50 63 80 100 125 150 175 200 250 300 350 400 450 500 Table 7 Selection of mAS Values 2 Auto Time A conventional automatic exposure control system in which the operator selects the technique kV and Diamond controls exposure timing mAS 3 Auto kV A fully automatic exposure control system in which Diamond manages the technique both initial and after start of the exposure filtration Mo Rh detector selection and exposure timing mAS The initial kV is determined by Diamond based on the compression thickness The user may change the initial kV During the exposure Diamond calculates the appropriate kV and mAS for optimum exposure time and film density 4 Other Modes In addition to the three main modes of operation above the Diamond AEC System may be pre programmed for a variety of customized user preferences such as Main or Backup film processor or film screen combination 1 or 2 C TECHNIQUE CHART FILM KODAK Min R 2000 SCREEN KODAK Min R 2000 and Min R 2190 FILM FUJI AD M SCREEN FUJI AD Mammo Fine FILM AGFA HDR and HDR C SCREEN AGFA HD and HD S Compressed breast _ 0 gt 8cm Specimens non Mag and Mag Note Implant displaced views and specimens may be phototimed if sufficient breast ti
40. cassette tray will automatically drive forward for exposure and afterwards automatically drive back again The cassette tray can be driven manually to the loaded or ejected position by sliding the cassette latch release handle Remove the cassette by pushing the cassette latch handle towards the front end of the Bucky Hold it in the forward position with your middle finger and pull the cassette out with your thumb and index finger See sections ProForm Synchro Bucky and MultiChoice Magnification for more information Fiaure 11 Latch Release Handle NOTE If a cassette is in the load position when power fails simply pull the Bucky off of the base the tray will shift to the eject position and the cassette may be retreived 5 Selecting an Exposure Mode Diamond s Exposure Control system has three modes of opera tion Auto kV Auto Time and Manual Select the mode with Auto kv 9 ad Auto Time the Mode select button The light at the left of the button indicates Manual the mode that is currently selected See the AEC System section Figure 12 Mode Selector for more information NOTE An exposure monitor will terminate the exposure in 50 msec with an error message if the AEC determines that a suitably exposed image cannot be achieved within the back up time 8 MM03341b 0 A MEDICAL P
41. d Wait and let cool down enough Remaining cooling time Er0071 indicated in timer screen Clear and try again If problem persists call service Er0072 Side collimator failure Clear and try again If problem persists call service Er0074 Internal communication error AEC Board not Clear and try again If problem persists call service answering Cable broken Er0075 Internal communication error Compression Clear and try again problem persists call service Board not answering Er0076 Internal communication error Stereo Board Clear and try again problem persists call service not answering Er0077 Internal communication error Collimator Clear and try again If problem persists call service Board not answering Er0078 Internal communication error Control Panel Clear and try again If problem persists call service not answering Er0080 Stereo movement back up time reached Clear and try again If problem persists call service Er0081 Cassette in rear position Clear and continue use Should cassette not move to the front position drive it there manually 1 C Arm rotation with the tube head in rear 1 For C Arm angles over 120 drive the tube head to Er0082 position disabled when vertical down C arm the front position For lowest Z position drive the tube angle over 120 2 Z movement down head is in front position 2 Drive the C arm to less than blocked when the C arm angle exceeds 122 122 the tube head must be in fro
42. e holder and the C Arm is shifted in the direction of the cassette holder relieving compression force Z UP The Carriage is driven vertically upward dual speed until a limit switch is activated Z DOWN The Carriage is driven downward dual speed until a limit switch is activated 5 Other Controls A MEDICAL PHYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND Parkback Retract 4 _ an NA Parkback Extend Figure 5 AutoRotate Controls Left 15 Right 15 Center 0 Vertical Z Up Vertical Z Down ww _ Rotate Tube Left CCW Rotate Tube Right CW Figure 6 Stereotactic Tilt Controls Figure THREE COVE Ens B DIAMOND SET UP 1 Attaching a Cassette Holder All cassette holders Bucky Multi Mag etc attach to Diamond in the same manner Rest the back edge of the Bucky on top of the front edge of the cassette holder base overlapping by about 2 3 cm helps align the guides in the Bucky with the slots in the base Keep it level while pushing it straight forward until the detent engages Remove it by pulling ure 8 Attaching the Bucky straight back firmly and deliberately NOTE The drive motor in the C Arm and the cassette tray in the Bucky are magnetically coupled If they happen to remain engaged for a moment when removing the Bucky you may hear a grinding sound which is normal
43. e6p3 M 006 Bulow C TEMPLATE DETECTOR OUTLINE imaging 1 E A MEDICAL PHYSICIST S GUIDE DIAMOND APPENDIX D TABLE MAXIMUM MA MAS The Maximum mA mAS values depend on kV and focus size the tube current is automatically selected by the microprocessor according to the table It is based on the technique kV chosen by the operator and the maximum target load permitted the x ray tube kW kV mA This enables minimum exposure times to be used Focus the large or small focal spot size nominal 0 3mm or 0 1mm respectively is automatically selected depending on the cassette holder in use kV 0 3 Focus 0 1 Focus kV 0 3 Focus 0 1 Focus mAS mA mAS mA mAS mA mAS mA 15 250 53 175 18 28 400 85 250 25 16 250 59 200 20 29 400 85 200 24 17 300 64 200 22 30 400 80 200 23 18 300 69 200 23 31 400 80 200 22 19 350 74 200 24 32 400 80 200 21 20 350 75 250 25 33 350 75 200 21 21 400 80 250 26 34 350 75 200 20 22 400 85 250 28 35 350 70 200 20 23 450 90 300 30 36 250 50 175 19 24 450 95 250 29 37 250 50 175 19 25 500 100 250 28 38 250 50 175 18 26 450 95 250 27 39 250 50 175 18 27 450 90 250 26 Table 8 Maximum mA mAS Values E VARIAN X RAY TUBE SPECIFICATIONS A complete set of the M
44. ed in the manual Background The purpose of the Density Control adjustment is to allow the technologist to fine tune the Automatic Exposure Control AEC to produce images that are correctly exposed over a wide range of breast thickness and compositions Both the 1994 and 1999 American College of Radiology Quality Control Manuals use the following language in this regard Because the relationship between exposure received by the film and resultant film optical density is not a linear one do not expect the fractional change in image optical density to necessarily correspond to the fractional change in mAS In general however as the density setting is increased above or decreased below the normal setting the mAS and image optical density should increase or decrease respectively It is recommended that there be a sufficient number of plus and minus density settings at least two plus and two minus settings and that each step should result in a 12 to 15 change in mAS or approximately a 0 15 change in film optical density emphasis added note the logical OR The Instrumentarium Performa AEC has been designed to provide approximately a 9 10 change in mAS with each step change in Density Control The change in optical density per step change in Density Control is a function of both the machine mAS and the film contrast Film contrast changes as a function of film optical density Figure 1 contains data taken from a typical high
45. editing program create a blank text file for recording data example C param aecdump txt Open a HyperTerminal session enter B connector configured with the port settings Figure 27 Alpha ID Serial Ports described above Switch on Diamond After it starts and connects with the PC HyperTerminal will display a prompt D1 05 7 where 1 05 7 is the software version Only for COM 1 output No prompt with COM 2 Select the HyperTerminal menu Transfer Capture Text In the dialog box choose the C blank text file and click Start m TL para COM 1 Session ewe ee HyperTerminal type param aecdump 1 or aecdump 2 and press Enter to send a command to Diamond to output AEC data After each exposure Diamond will send data to the PC COM 2 Session Begin taking exposures Diamond will send data to the PC When the session is completed end the text capture with menu Transfer Capture and Stop Switch off Diamond close HyperTerminal and disconnect the serial cable Switch on Diamond Figure 22 Capture Text Dialog NOTE If the cable to the PC is still attached when Diamond is restarted Diamond will re establish a connection J INTEGRATED QUALITY CONTROL IQC Integrated Quality Control IQC is a Diamond feature designed to keep image density the same even if the film processor environment has chan
46. ertain error conditions the cassette is automatically moved back ejected to the opening ready for removal from either side The system permits manual cassette removal in the event of power failure or system malfunction The ProForm Synchro Bucky consists of a one part carbon fiber cover with rounded corners Buckies utilize a common grid motor integrated into the Diamond s C Arm for both Bucky sizes 12 MM03341b N A MEDICAL PHYSICIST S GUIDE TO DIAMOND DESCRIPTION OF MAIN FEATURES 3 Generator Synchronization Grid reciprocation is monitored by Diamond s exposure control system If it calls for an exposure time that extends into a grid reversal the generator suspends radiation for approximately 60 msec at the apex of grid turnaround This brief cessation is transparent to the operator and patient but under certain conditions may cause some non invasive kVp meters to sense the abrupt fall in the radiation waveform and prematurely abort collecting data Conversely some non invasive devices may not detect the brief cessation of radiation and display the time duration from initial exposure start to final termination The Diamond post exposure mAS and Time values account for the sum of the off time at each grid turnaround and display only the net exposure time This synchronization is engineered to prevent gridline artifact and may be observed on a kV waveform 4 Grid
47. ged Diamond can correct the AEC exposure times by up to 40 after which the unit gives an error code and prompts for a check 16 MM03341b INSTRUMENTARIUM imaging MEDICAL PHYSICIST S GUIDE TO DIAMOND DESCRIPTION OF MAIN FEATURES of the film processing system The IQC test is done with a phantom exposure After the exposure the film is developed and its density checked with a densitometer If the measured optical density is different than the current setting in Diamond the new value is entered in QA Quality Assurance establishing a coefficient that modifies the AEC exposure time calculation MM03341b 1 INSTRUMENTARIUM Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM IV AUTOMATIC EXPOSURE CONTROL SYSTEM Diamond Automatic Exposure Control AEC is a sophisticated all solid state microprocessor based system Designed around the revolutionary AutoPoint Detector the AEC System automatically 1 selects the most appropriate among eight detectors arrays 2 selects the beam filter molybdenum or rhodium 3 selects the initial kV and then adjusts the kV on the fly a pre exposure analysis isn t necessary and 4 calculates the mAS time required for proper optical density Additional features such as PaddleLogic Exposure Monitor and Synchro Bucky combine with the operation of the AEC System to provide extremely high tech yet user friendly performance A FEAT
48. hen C4 or C3 is selected either manually or by AutoPoint C4 and possibly C3 may be slightly de tuned De tuning means that instead of driving C4 to match the desired OD its gain will be set to either Produce a local C4 density that is about 15 less than the desired OD but still within 0 30 MOD or Produce a chest edge C1 density that is less than 2 00 OD or as determined by consulting physicist or customer Example if the client desired OD is 1 80 the C4 local area will be set for about 1 53 OD 2 Definitions MQSA PGHS 6 uses several terms in describing the process of testing a device The following definitions for Configuration Mode and Detector will help the reader apply the regulatory terminology to Diamond and prepare it for evaluation a Configuration The operational setup of Diamond A combination of the cassette holder Bucky or magnification stand and X ray beam filter molybdenum or rhodium Bucky Mo is considered the primary configuration because it is used most frequently NOTE The aluminum filter AL is available only in manual technique mode The focal spot size If sf and tube current mA are managed by Diamond and not user selectable Configuration Cassette Holder Filter Target Primary Bucky Mo Mo Secondary Bucky Rh Mo Tertiary Mag Mo Mo Quaternary Mag Rh Mo MM03341b 25 INSTELIHENTAEIDUM imaging A MEDICAL PHYSICIST S
49. hese service programs L Physicist Mode is designed to simplify inspection of various non standard settings and paddle receiver combinations by Medical Physicists and WARNING Service Program Menu contains programs with software parameters and adjustments that affect the safe and proper performance of Diamond Only trained service technicians are authorized to access these other programs Range Parameter Default Notes Grid Off Disable Enable Grid Movement Ideal for non invasive kVp Meters with System triggering problems relating to Synchro Bucky Large Focus Size Selection Over ride normal focal spot size for Bucky large or Focus Small Mag small Also sets collimator front plate to anterior large or posterior System small setting Paddle 5 Paddle Selection Over ride normal paddle detection and PaddleLogic S operation beam collimation and AutoPoint detector selection Cassette Holder Selection Over ride normal cassette holder detection and Holder Holder beam collimation If no cassette holder is attached the collimator is driven System fully open Off Disable Enable kV Limit If disabled and manual mode is selected any kV System the range 15 to 39 can be used Over ride of collimation is constrained to the actual size of a mounted receiver Ex The large paddle and large Bucky are selected but only an 18x24 Bucky is attached so
50. ield Localizer Light a 1 ROTATION 11 1 Anatomic C Arm Rotation ACR 12 2 AutoRotate ios 3 Mirror 2 44420 002 12 E Alpha ID II Film ID 12 F ProForm Synchro Bucky 12 1 Patient Comfort and 12 2 Cassette Tray 12 Generator Synchronization 13 IV AUTOMATIC EXPOSURE CONTROL SYSTEM A 18 1 Absolute AEG 18 2 PaddleLogic 3 Density Control 18 4 AutoPoint Detector B Modes Of Operation 18 Te nieto nente 2 Auto Time C Technique 241 D AEC Operation 1 OVerview renes 2 Auto kV Functional Description z 3 AutoPoint E AEC Performance Evaluation 1 Background 2 Definitions ioter 3 Testing Procedure MQSA Method 2 26 4 Optional Detector Reproducibility 28 V PHANTOM IMAGING amp ARTIFACT EVALUATION VI DIAMOND X RAY TUBE A Target and Filter Information B Tube Geometry and Dimensions VII THF X RAY GENERATOR
51. incorporates the highly acclaimed ECS bi directional compression system Delta32 TACT 3 D digital and Stereotactic option THF Tuned High Frequency generator a digital ready design bi angle rotating anode X ray tube ROC grid option and easy patient positioning Despite the breadth and sophistication of fresh technology implemented in Diamond it continues the tradition of core qualities found in Instrumentarium s Performa and Alpha IQ of the past comfort for the patient and ease of use for the technologist Breast Imaging System is a high quality x ray imaging device intended for A SCOPE Instrumentarium recognizes the importance and supports the efforts of medical physics in the delivery of quality mammography service This Guide has been prepared to assist Medical Physicists as they work with Diamond Breast Imaging System during Annual Mammography Surveys and consultations This document is written for the practicing Medical Physicist who already possesses a basic familiarity with the operation of mammographic x ray systems Features and functions specific to Diamond are described so that the Medical Physicist may efficiently and effectively work with the unit The reader is advised that although this Guide is generally suitable for worldwide use portions of it are directed toward and address the regulatory environment in the USA namely the Mammography Quality Standards Act MQSA This effort is intended
52. ing small image receptor with Imaging mode grid Focal spot large focal spot mA 100 Phantom thickness AEC Mode Filter Density 2cm Auto kVp 1 78 4 Auto kVp 1 75 6cm Auto kVp 1 83 8 Auto kVp 1 80 Mean Density 2 6 cm MQSA Allowable Range 1 79 1 64 to 1 94 Image Mode Tracking mA 100 Phantom thickness 4 BR 12 Anode Filter Mo Mo Image Mode AEC Mode Filter Density small grid Auto kVp 1 75 large grid Auto kVp 1 86 Magnification no grid Auto kVp 1 86 MM03341b 35 maging A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX Overall AEC Performance Mean Density Density Range Recommended Range 1 80 3 to 1 86 1 50 to 2 10 AEC Phototimer Uniformity Function Imaging mode small grid Focal spot large mA 100 kVp 26 Density Selector 0 Cassette ID 41 18 x 24 Relative to Mean O D Photocell Selector mAS Density Setting Measured Density Change Change Left 2 1 80 5 0 07 Left 1 1 83 4 0 10 C 4 1 65 1 0 08 C 3 1 66 1 0 07 C 2 1 78 0 0 05 C 1 1 78 1 0 05 Right 2 1 71 1 0 02 Right 1 1 63 1 0 10 Mean 1 73 Action Limit The AEC shall be capable of maintaining film optical density within 0 15 of the mean when each independent photocell is selected for a 4 cm
53. ion from the MOD DETECTOR C2 Config Holder Filter Mode Thickness OD Deviation 5 Primary Bucky Mo Auto Time 4cm 6 Secondary Bucky Rh Auto kV 4cm 7 Secondary Bucky Rh Auto Time 4cm 8 Tertiary Mag Mo Auto Time 4 9 Tertiary Mag Mo Auto kV 4cm MM03341b 27 IRSTREUMENTARIUM Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM 10 Quaternary Mag Rh Auto kV 4cm 11 Quaternary Mag Rh AutoTime 4 g Confirm AEC Performance for Other Detectors Setup Diamond with the Primary Configuration and Mode and a 4 cm test object Compare the film OD obtained from each of the seven remaining detectors to the MOD obtained from the first detector Use the regulatory action limit of 0 15 OD 0 30 OD is permissible for C3 and C4 which are considered special detectors because of their deep anterior location Manually select AutoPoint turned off the Detector according to the table below Measure and record the film OD and determine the deviation from the MOD CONFIG Primary Bucky Mo Detector Mode Thickness OD Deviation 12 C1 Auto kV 4 cm 13 Auto kV 4cm 14 R1 Auto kV 4 cm 15 22 4 16 R2 Auto kV 4 cm 17 C3 Auto kV 4 cm 18 C4 Auto kV 4cm 4 Optional Detector Reproducibility a
54. iques 34 MM03341b 1 1 5 A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX IX APPENDIX A ARTICLE ONE PHYSICS TESTING PROCEDURES FOR DIAMOND Melissa C Martin M S FACR July 9 2003 Testing of the Automatic Exposure Control systems on mammography equipment has become one of the most challenging sections of an Equipment Evaluation for the medical physicist The medical physicist must make enough measurements to verify compliance with currently applicable MQSA requirements as a minimum and to further verify that the unit will meet the performance demands placed on it by the facility This usually means more than the minimum number of tests should be made however with the Diamond unit if all eight independent phototimers were evaluated for all thicknesses of 2 to 8 cm this would mean 64 films and measurements just for this portion of the Equipment Evaluation A proposed method of evaluation that has been accepted by the FDA to meet MQSA requirements and cover the thickness range of 2 to 8 cm is to fully test the C 2 position for all thicknesses of 2 8 cm and verify that the Optical Density for all films at this position is within 0 15 of the Average O D for this position and then check the O D with the 4 cm phantom placed at each of the other positions The tables below show the performance achieved on a recent installation using this test procedure Thickness kVp Track
55. ite LAT causes the C Arm to automatically rotate to the opposing lateral projection E ALPHA ID FiLM ID LABEL The film identification system JANE DOCE 3 8glb 74 Alpha ID can be a helpful data OMEGA MEDICAL CLINIC q g3 gb recording or troubleshooting tool STREET ANYTOUN during an annual survey The post 04 24 01 08 48 Mo C3 0 000 B RCC exposure technique information is 225 9 1 015 1 4Y3mGy 5 Ucm 145 transferred to the label camera for subsequent flashing onto the film see the Flash Label Explanation section in the appendix for more info PROFORM SYNCHRO BUCKY 1 Patient Comfort and Safety The Bucky system for Diamond has been carefully engineered with interventional procedures and patient comfort in mind All patient contact surfaces are smooth and rounded and absent of any seams or screws resulting in increased safety and comfort In order to achieve this the cassette DIN standard is inserted into a lateral slot that is 13cm 7cm for large Bucky anterior from the chest wall end of the Bucky This design results in a completely sealed enclosure under the patient ideal for preventing fluid entry during interventional procedures 2 Cassette Tray Operation Figure 18 ProForm Bucky When the cassette is inserted it is automatically moved forward loaded into position against the front edge of the Bucky ready for exposure After an exposure or under c
56. l number of the unit Name of the operator who experienced the problem Software revision level on the LCD display when power is switched on 2 AECissues Film screen combination in use 2 MM03341b P imaging 3 A MEDICAL PHYSICIST S GUIDE TO DIAMOND AN INTRODUCTION TO DIAMOND Processing time and developer temperature What is the gross fog speed index and contrast index of the film developed in the processor Was any work done on the film processor just prior to the problem Did problem appear suddenly or gradually Breast compression kV selected type of view mAS of exposure detector positioning filter selected which imaging mode Other concerns a 5 What is the history of the problem Error codes on the display What have you done to attempt a fix Is it permanent failure or intermittent If intermittent how often per day Did problem appear as a result of some other work performed on the unit Is any other equipment exhibiting intermittent problems 4 Reference Materials Haus AG Jaskulski SM The Basics of Film Processing in Medical Imaging Madison MM03341b 1 WI Medical Physics Publishing 1997 Haus Arthur G ed Advances in Film Processing Systems Technology and Quality Control in Medical Imaging Madison WI Medical Physics Publishing 2001 A MEDICAL PHYSICIST S GUIDE TO DIAMOND IAS TRUER TARA imaging GETTING FAMILIAR WITH DIAMOND 1 GETTING
57. lations of individual countries must be complied with The user must have permission to use an x ray device for mammography Radiation protection measures should be used Prior to examination it is recommended to make sure that the doctor knows if the patient is pregnant If someone has to be close to the patient protective clothing must be used The maximum radiation that the system is capable of producing corresponds to 596 of the typical CT radiographic exposure However the user should wear a dose recording device and follow local regulations for radiation protection MM03341b 1 P imaging The optional radiation shield must be used or the unit must be operated from a shielded control room significant zone of occupancy is 2 meters During the exposure visual and audible contact should be maintained with the patient The freestanding radiation shield can be positioned as required in the X ray room An Instrumentarium Imaging mammography accessory storage unit is available as an option and may be placed behind the freestanding radiation shield Diamond with radiation protection is in accordance with IEC 601 1 3 1994 A MEDICAL PHYSICIST S GUIDE TO DIAMOND AN INTRODUCTION TO DIAMOND 3 Safety Features amp Error Codes Diamond incorporates many safety features designed to offer protection from physical injury and unnecessary radiation dose to the operator and patient A few examples Exposures without a cassette present or double expo
58. level dtr_xray 7 dec 2682 MAs dec 28 User density 7 Filter 0 Casholder 1 Time before th comp 252 Det offset dtr_gndl 0 dec 52 Det offset dtr_gndl 1 dec 52 Det offset dtr_gndl 2 dec 72 Det offset dtr_gndl 3 dec 28 Det offset dtr_gndl 4 dec 70 Det offset dtr_gndl 5 69 Det offset dtr_gndl 6 dec 69 Det offset dtr_gndl 7 dec 67 tecexpt ime 0 0 tecexptime 1 292 tecexptime 2 0 tecexptime 3 0 Targettime dec 2200 Int density GetInternalDensity 100 Full density 100 Preprog density 100 Autokvlimit 3 coefficient 110 Dtr 0 values in offset cnt 252 52 523152 52 52 52 52 52 52 Dtr 1 values in offset cnt 153252 1523252 52 52 52 52 52 53 Dtr 2 values in offset cnt 72 72 72 72 173 19317231172 1232 Dtr 3 values in offset cnt 130 29 29229 29 29 28 28 28 30 Dtr 4 values in offset cnt 27027 0 704 70 55 70570471 07111570 Dtr 5 values in offset cnt 69 70 70 70 69 69 69 69 69 69 Dtr 6 values in offset cnt 69 69 69 69 69 69 68 70 70 69 Dtr 7 values in offset cnt 68 69 69 69 67 67 68 67 67 68 LowMaLimit 0 ARC tahlez Figure 38 Data Output param 2 INSTRUMENTARIUM Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX Notes 46 MM0334 1b Notes
59. ls Back up Release In the event of power failure Diamond releases compression automatically except when the Delta 32 unit is connected to the system or if AutoRel is de selected Negative Force Diamond monitors downward pressure or negative force against the paddle such as an obstruction during the release operation C ECS COMPRESSION ECS Easy Compression System adds one more unique movement to Instrumentarium mammography systems the independent movement of the C Arm in relation to the compression paddle This movement is also independent of the angle of the C Arm and it is different from the normal up and down movement of the C Arm carriage With the ECS movement the breast is compressed from the mobile margin i e from below The movements are controlled using the ECS foot pedal The ECS system uses the natural mobility of the breast to increase the clinical image quality and patient comfort ECS makes it easier to elevate the breast and open the infra mammary fold thereby maximizing the amount of breast tissue visible in the image In positioning ECS does not replace the skill of an experienced radiographer technologist but helps her carry out the positioning more easily In clinical usage the amount of images that have pectoral muscle visible in CC projections has increased from 20 the amount prior to the use of the ECS system to 50 The ECS compression system can also be used to perform conventional compression techn
60. nherent Filtration 0 mm AL equiv beryllium port material Added Filtration nom Molybdenum 25 um Rhodium 25 um Aluminum 50 um Anode Heat Capacity 300 kHU Anode Rotation Speed 3600rpm 60Hz B TUBE GEOMETRY AND DIMENSIONS Source Image Distance SID 660 mm 26 Focal Spot Size dual IEC60336 Large 0 3 mm Small 0 1 mm Target Angle bi angular Large 16 Small 10 Tube Angle 4 Reference Axis 46 2 mm from chest wall edge MM03341b 31 INSTRUMENTARIUM imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND THF X RAY GENERATOR VII THF X Ray GENERATOR The compact revolutionary X ray generator in Diamond further enhances the already exceptional design found in previous Instrumentarium products It remains one of the smallest designs in mammography and with recent improvements one of the most robust Engineered around a variable high frequency H bridge resonance regulator design tuned high frequency or it is able to withstand open circuit short circuit and arcing conditions Because it operates near its resonant frequency switching harmonics and radiated noise are greatly diminished enabling Diamond to meet stringent IEC and EU regulatory requirements A OPERATING PRINCIPLES 9 KV Feedback from X Ray Tube 300 Power Supply Set KV from X Ray Control To X Ray Tube
61. nt position Er0084 Transmit buffer overflow in Supervisor Clear and try again If problem persists call service software Release compression manually Er0087 Movement inhibited during compression Release compression and try again C Arm center limit not found Drive manually in the center If problem persists call Er0089 2 ice 0090 Tube in front position Remove Delta 32 or biopsy paddles to enable tube head AutoDrive Er0091 Z movement disabled in Specimen mode Clear and continue If a patient is to be examined exit the Specimen mode Table 10 Diamond Error Code Guide MM03341b A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX H BACK PANEL CONNECTIONS P imaging e e CONTROL PANEL _ WARNING LIGHTS FOOT PEDALS em Item Name Description 1 COM1 PC and Service SW Connection 2 COM2 Alpha ID II Film Labeler 3 FOOT Foot pedal connection PEDAL 4 FOOT Foot pedal connection PEDAL 5 CONTROL Operator control panel PANEL 6 DELTA Delta 32 workstation 7 WARNING Signal control for opt LIGHTS room warning lights 8 Line cord cable 9 Circuit Breaker 15A Figure 35 Back Panel Connections 44 MM03341b P imaging DATA OUTPUT SAMPLES A MEDICAL PHYSICIST S GUIDE TO DIAMOND APPENDIX DC1 02 7 gt param aecdump 1 aecdump 1 DC1 02 7 gt Exp Nr 1936 15 08 Preprog 1 Detectors 4
62. nunciator and the accumulating value on the timer display If the exposure button is released prematurely the exposure is immediately terminated and an error message is displayed on the LCD screen MM03341b 9 P imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND 2 Automatic Compression Release Diamond s Automated Compression Release AutoRel decompresses the breast without operator input immediately after completing an exposure or in the event of a power failure AutoRel can be toggled on off by pressing Function Key 3 on the control panel labeled with Auto Rel on the LCD display If a power failure occurs while AutoRel is off the C Arm and or paddle will not move Also if the Delta32 Stereotactic device or any of the biopsy paddles are in place AutoRel is inhibited however compression can Figure 17 AutoRel Function Key be released with the foot pedals or manual compression wheels Refer to the Compression System section for more information 3 Display Accuracy amp Brief Specifications Display and several system specifications are included here for the convenience of the Medical Physicist performing an annual survey A complete list may be found in Section 10 of the Diamond Operating Instructions kV Range 15 39 kV in 1 kV increments kV Accuracy 1 5 kV ripple 596 large focus 2 500 AS Range MAS Kange mall focus 4 300 mAS Accuracy
63. ond is equipped with 2 serial data communication ports The first Com 1 is configured for system calibration and programming and for downloading AEC and parameter information The second port Com 2 is configured for sending label data to the Alpha ID II film camera 1 Data Formats Test data may be gathered from one of three output formats see Data Output Samples in the appendix Output Type Port Notes Comments Exposure Requires DB Printout of essential post exposure data cassette holder filter COM2 9 null modem exp time kV mAS density thickness force angle laterality Flash Label adaptor dose detector exp Basic AEC data output each detector s signal strength and aecdump 1 COM1 limited post exposure data time detectors used pri and sec kV exp time thickness exp Detailed AEC data output same as above plus mAS density filter cassette holder kV shift pattern and service data linearity cal pre comp exp time detector offset target time AkVLimit IQC coef aecdump 2 Table 5 Data Output Types 2 Equipment Required All three formats are output as standard ASCII text data and may be viewed or saved with a PC communications program Equipment required Laptop Computer PC Communication program such Windows HyperTerminal by Hilgraeve Inc Standard RS 232 Serial Cable DB 9FM to DB 9M available from Instrumentarium part code 85102
64. or the operator to adjust the height Z Up Down of the c arm when rotating from CC to OBL projections 2 AutoRotate Located on either side of the c arm is a group of controls that conveniently rotate the c arm to one of five pre programmed projection angles The automatic nature of these controls can be set by a service technician to behave in one of four ways depending on local safety regulations and user preference OFF dead man operation press hold button until rotation stops ON unattended operation press release button PADL UP unattended operation same as ON but only when paddle is fully released C PEDAL hands free dead man operation press release button then press hold the CARM foot pedal until rotation stops Auto rotation is inhibited if 1 no paddle is attached 2 an invasive procedure paddle is in use or 3 the system detects compression force gt 30N 3 Mirror Angle The OBL button normally drives the C Arm to a predefined default angle for example 45 which may afterwards be fine tuned to the patient s anatomy With the MirrorAngle feature enabled pressing the opposite OBL button after an exposure causes the C Arm to automatically rotate to the same but opposing angle The same principle holds true for the LAT buttons which normally drive to the default 90 projection If the angle is adjusted with the direct control buttons and then an exposure is taken pressing the oppos
65. oup is passed to a high gain amplifier current to voltage converter and then to a multiplexer MUX which serially combines the 8 signals into a common signal path Amplification amp Conversion Hardware The output of the detection hardware is sent to the next stage where a controlled variable gain offset amplifier and analog to digital converter ADC further process the signal stream The AEC u C transfers this digital signal via high speed system communication bus to the main p P for exposure time calculation The scans all 8 detectors signals to find the lowest signal strength represents the area of greatest absorption in the patient and applies that value to the exposure time algorithm Software Algorithm The manages all operation of the generator kV mA focal spot and exposure timing start stop Synchro Bucky After it begins an exposure sequence and receives the AEC detector data stream it processes the information and applies the data to a non linear polynomial equation The installer can manipulate the equation using software parameters that compensate for the non linear characteristics of film screen receivers 2 Auto kV Functional Description The function of Diamond Auto kV mode might be compared to the manner in which technologists operate general radiography systems First the technologist evaluates the patients size and weight and considers the view chest vs extremity to determine the optim
66. out estimating absorbed dose refer to Spectral Dependence of Glandular Tissue dose in Screen Film Mammography Wu Xizeng Wu X Barnes Gary T Tucker Douglas M Radiology 1991 179 143 148 Normalized Average Glandular dose in Molybdenum Target Rhodium Filter and Rhodium Target Rhodium filter Mammography Wu Xizeng Wu X Gingold Eric L Barnes Gary T Tucker Douglas M Radiology 1994 193 83 89 10 MM03341b IRSTRUMENTARIUM imaging A MEDICAL PHYSICIST S GUIDE DIAMOND DESCRIPTION OF MAIN FEATURES 111 DESCRIPTION OF MAIN FEATURES A PARKBACK A unique feature of Diamond is the capability to move the tube head back and away from the patient 19 cm 7 1 2 for totally free access to the breast from above This is particularly useful when positioning oblique or lateral projections or for interventional procedures such as a biopsy Movement is controlled by buttons located a on either side or b on top of the tube head Pressing a button drives the tube head until it comes to its end position ParkBack operation may set for unattended press release operation dead man press hold operation depending on the local safety regulations and user preferences AutoPark operation can be programmed to automatically park when the C arm rotates to projections over 15 Safety clutch sensor if tube head movement is obstructed ParkBack operation is aborted and an error message is displayed
67. paddle see PaddleLogic are being used 1 Aperture Plates Diaphragms The automatic motorized collimator allows any rectangular collimation For other collimated shapes i e semi circular spot sizes corresponding special diaphragms must be inserted manually 2 X Ray Field Localizer Light The X ray field illumination light is switched on automatically when the compression foot pedal is pressed the tube head is being driven forward or the collimator light Switch is pressed It is inhibited when the tube head is in the ParkBack position The light is switched off automatically after 40 seconds adjustable by service technician from 20 60 sec when the exposure button is pressed or when the collimator light switch is pressed D ROTATION The C Arm rotates 185 from the vertical position 0 number of operator control are provided to easily adjust the rotation angle Direct control can be taken by pressing and holding the Rotate CW or Rotate CCW buttons on the Position Control Centre a or the tube head cover b until the desired angle is reached Automatic operation is achieved with the AutoRotate controls c MM03341b 44 A MEDICAL PHYSICIST S GUIDE TO DIAMOND DESCRIPTION OF MAIN FEATURES Pimaging 1 Anatomic C Arm Rotation ACR The axis of c arm rotation for Diamond is close to the film plane permitting the image receiver to closely follow the contour of the breast This minimizes the need f
68. r A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM Diamond recognizes the compression paddle and the cassette holder depending on the PaddleLogic settings in use and collimates the X Ray field size and disables those detectors that are outside of the radiation field or not under the compressed part of the breast a Multi Detector Considerations X Rays Detector Detector Amplifier MicroProcessor Vref Figure 26 Single Detector AEC Systems Traditional AEC detector designs utilize a single detector either solid state or phot multiplier tube PMT that is mechanically moved under the patient region of interest ROI In these designs the AEC system is generally calibrated and tested with the detector moved to the most clinically relevant location Only the object density or thickness or beam energy kV mAS is changed Because there is only one detector and signal path any variability introduced by the detector or AEC amplifier electronics would be the same despite detector location Evaluating the performance of this type of detection system is a manageable process of running a series of exposures to the single detector and determining the coefficient of variation from exposure time or MAS or optical density A multiple detector design introduces concern about multiple sources and signal pathways Each detector and subsequent amplifier circuit may introduce a
69. splay N Angle Display Vertical Control 1 Up 2 Down Paddle Release Button Manual Compression Knob TA Figure 3 Positioning Control Centre The Position Control Centre cleverly locates every function and display used by a technologist for positioning a patient in close proximity with the patient permitting better patient contact and faster operation The Centre moves in concert with the compression system making the controls readily available at all times 4 Foot Pedal Control Figure 4 Foot Pedal Control The Diamond Foot Pedal controls several systems of motion that run at various speeds depending on the process being called upon CAUTION The PAD and ECS controls will act to apply force between the compression plate and the top of the cassette holder C ARM Only the C Arm is shifted in the direction of the tube head at a slow speed 6 MM03341b INSTRUMENTARIUM 9 imaging PAD Only the Compression Paddle is driven toward the cassette holder at high speed during approach and slow speed upon contact with the patient The collimator light is automatically turned on at the same time ECS The compression paddle is driven toward the cassette holder and the C Arm is shifted in the direction of the tube head see the ECS Compression section for more information REL The compression paddle is driven away from the cassett
70. ssue covers the photocell closest to the chest wall COMMENTS 1 Maintain exposure times between 0 5 and 2 5 seconds Decrease kVp if times are less than 0 5 seconds and increase if they are more than 2 5 seconds 2 Ifexposure times are within indicated times use or density settings to achieve optimal film density 3 Your technique may vary from those indicated above depending on film density preferences processor or film irregularity or different film screen combinations Rhodium use for very dense breasts 6 cm or greater No need to increase kV Magnification views increase technique by 2 3 kVp if exposure time exceeds 5 seconds MM03341b 19 1 IRSTRUMENTARIUM Bimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM D AEC OPERATION 1 Overview The Diamond AEC System consists of three main parts detection hardware amplification and conversion hardware and the software algorithm All aspects of detector selection signal level control and conversion exposure timing and technique etc are managed by the main microprocessor p P or the AEC micro controller u C either automatically or in response to operator input Detection Hardware Electromagnetic radiation is converted to a proportional low level electrical current in the detection hardware using 8 arrays of photo diodes each in a parallel configuration The low level current signal from each diode gr
71. sure are prevented Mechanical movement vertical rotation etc is inhibited if compression force is detected fthe proper optical density can not be achieved with the technique selected the Exposure Monitor will terminate the exposure in 50 msec Operational or safety related errors that prevent exposure or some other function are explained to the user in the form of an error code and description on the control panel If you encounter any errors during a survey consult the Diamond Error Code Guide in the appendix C OTHER SOURCES OF INFORMATION 1 On Site OEM Documentation Each Diamond system is delivered with a complete set of original factory documentation including 86500 Diamond Operation Instructions 86501 Diamond Installation Instructions 86502 Diamond Service Manual 86513 Diamond Technique Chart 86528 Diamond Quick User Guide Check with your client or the equipment installer for their location 2 Contact Information Instrumentarium Imaging Inc Product Support Division Mammography 300 W Edgerton Avenue Milwaukee WI 53207 USA ph 800 558 6120 fax 414 481 8665 URL http usa instrumentarium com Operations Coordinator 6318 darin grebe usa instrumentarium com 3 Calling For Help To better assist you in answering questions or resolving technical or operational issues the support staff at Instrumentarium may require additional information 1 General Seria
72. sure started Er0038 Cassette holder not attached when trying to Attach cassette holder expose Inhibit exposure Stereo not in 0 degrees when exposing With Delta 32 drive the stereo arm first to left and right Er0041 then back to 0 position If you have no Delta 32 call service Er0042 Stereo movement error Check that Delta 32 unit properly attached Er0043 Vertical movement motor back up time Clear and try again If problem persists call service reached Er0045 ECS motor back up time reached Clear and try again If problem persists call service r Arm rotation back up time reached ear and try again If problem persists call service Er0048 C A ion back up ti hed CI d try again If problem persi Er0051 C Arm angle measurement failure Drive to Clear and try again If problem persists call service predefined angles not allowed Er0053 General communication error with internal Clear and try again If problem persists call service electronics Er0054 External communication error with serial port Clear and try again If problem persists call service Buffer overflow Er0055 External communication error with RS232 Clear and try again If problem persists call service Er0057 mA failure Clear and try again If problem persists call service Ty ag p p 0058 Anode start failure Clear and try again If problem persists call service y ag Er0059 Anode run failure Clear and try again If problem persists c
73. t reduces mA with small breast thickness MM03341b 33 1 Ia TRUE TAR Pimaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND COMPRESSION SYSTEM VIII COMPRESSION SYSTEM The Diamond compression system may be operated either manually or by automatic motor drive Automatic operation is typically used to capture the breast followed by manual fine tuning of the compression force if necessary Automatic operation is achieved using the foot controls hands free operation improves patient positioning The compression force pre selection keys limit the maximum automatic force that can be applied to the breast the left key decreases and the right key increases the limit A FOOT CONTROLS C ARM Only the C Arm is shifted in the direction of the tube head at a slow speed The compression paddle motor is not energized PAD Only the Compression Paddle is driven toward the cassette holder The collimator light is automatically turned on at the same time Operation is dual speed meaning a high speed during approach and a slow speed upon contact with the patient The drive speeds and the speed change threshold force are adjustable by a service technician ECS The compression paddle is driven toward the cassette holder and the C Arm is shifted in the direction of the tube head The C Arm motion is in synchronization with same velocity as the compression paddle but in the opposite direction effectively holding
74. tage alters the beam KV energy and consequently the rate of radiation Diamond re examines the detector signal and computes a new exposure time The process may be repeated again and in each instance the kV may shift upwards or downwards Note that this entire sequence of events Time occurs in real time within several Figure 24 KV Shift Waveform milliseconds after the start of exposure Diamond needs no pre exposure analysis of the patient After the exposure is complete the final kV is displayed The Auto kV performance can be optimized and configured by the installer who considers and evaluates receiver response characteristics speed contrast client preferences desired kV and image density Diamond performance target efficiency and local patient population The configurable items are the initial kV table kV versus breast thickness maximum permitted kV shift and desired exposure time range target time and target time limits AutoPoint Detector The AEC Detection hardware is designed with eight separate solid state detector arrays Each one consist of either 22 or 12 parallel photo diodes sub detectors that are arranged in an elliptical shape with a major axis of 42 mm and a minor axis of 32 mm half ellipse at the chestwall edge The overall coverage area is 13 cm A P and 17 cm L R The detectors along the chestwall edge are 5 mm from the edge of
75. to be a living document The reader is encouraged to remit comments and suggestions see Contact Information for items to be added to this Guide that will benefit Medical Physicists and help facilities to obtain optimal results from their Diamond We invite you to discover the sophistication of design and simplicity of operation of the Diamond Breast Imaging System B PRECAUTIONS WARNINGS 1 Intended Use Diamond is intended only for mammography examinations no other uses are permitted Two film screen formats 18x24 and 24x30 and several cassette holder and digital options are available The unit has been designed for stationary use however special design elements have been engineered for clients choosing a mobile van application contact Instrumentarium for details When energized this device emits filtered X Ray radiation for medical purposes The Diamond system is CE marked in accordance with MDD 93 42 EEC and its design complies with IEC 60601 1 It fulfills the EMC requirements of IEC 60601 1 2 as a Class A device The unit is tested and certified according to UL 2601 1 and CAN CSA C22 2 NO 601 1 WARNING Never use the equipment if it is suspected that any electrical or radiation emitting component is defective or inoperative WARNING Only trained licensed persons are allowed to operate the Diamond unit 2 Radiation Safety Since radiation is harmful to the human body the radiation protection regu
76. udes an operational mode Service Mode that limits these automated actions bypassing the normal function of the system This mode enables the service technician to perform various calibrations adjustments and evaluations without the usual safety constraints NOTE AEC and generator performance and duty cycle limiting behave the same in Service Mode as they do in Normal Mode 1 Using the Service Mode Interface To access Service Mode simultaneously press kV and Den buttons for 3 seconds until the display indicates SERVICE To return to Normal Mode simultaneously press kV and Den buttons for 3 seconds until SERVICE clears from the display CAUTION Diamond may update the kV or density display before recognizing the second button press Verify the kV and Density settings before taking exposures 2 Service Program Menu The Service Mode Interface permits access to a Menu that contains special programs for system setups calibration and diagnostics The menu has been organized into several categories called Groups They are A System Setup B Defaults C Diagnostics D AEC E C Arm Rotation F Collimator G Compression H Filter Generator J Tube Park Stereo Movement and L Physicist Mode MM03341b 13 A MEDICAL PHYSICIST S GUIDE TO DIAMOND DESCRIPTION OF MAIN FEATURES service technicians The table below lists Diamond operation that can be altered P imaging One of t
77. um technique kV and or mAS to use perhaps consulting a technique chart as a guide After taking the exposure and evaluating its outcome exp time image quality etc the user might adjust the technique slightly to improve the quality of subsequent exposures AEC Parameters Mathmatical Constants Linearity Parameters Generator Voltage kV EXPOSURE TIME CALCULATION e exp Terminate Exposure Within 0 mSe Compressed Thickness cm Detector Data KV Shift COMPLETE EXPOSURE Figure 23 Auto KV Block Diagram 20 MM03341b 3 MM03341b A MEDICAL PHYSICIST S GUIDE TO DIAMOND AUTOMATIC EXPOSURE CONTROL SYSTEM In Auto kV mode Diamond automatically selects the initial kV based on the compressed breast thickness much like an automated technique chart The Auto kV chart is a software look up table programmed by the installer In the beginning of exposure detector data representing the rate of radiation exiting the patient is examined by Diamond which calculates the exposure time necessary to achieve the desired optical density Then it compares the results of this calculation against a Target Time lookup table If they are not Final in agreement Diamond shifts the kV like a technologist who would increase kV to reduce motion blur Initial or decrease kV to increase image contrast Because the change in tube vol
78. y preset by the installing engineer In some installations the AEC Auto kV decision point between adjacent kVp values may occur at x ray absorption levels that are very similar to those of the accreditation phantom While such AEC settings do not affect clinical imaging repeated phantom exposures in Auto kV mode may produce alternating kVp s and associated alternating mAS values This type of variability can elicit concern from QC technologists and inspectors Fine tuning of the AEC by the service engineer can move the decision point of the Auto kV algorithm so that phantom imaging produces a consistent kVp and therefore a consistent mAS value Alternately phantom imaging may be performed using the AEC Auto Time Mode with a documented explanation describing the reason and referencing this document When performing the artifact evaluation it is recommended that clinically representative kVp values be used Artifact evaluations for the grid and molybdenum filter are typically performed at 25 kVp using about 4 cm of uniform phantom material such as acrylic Artifact evaluations of the rhodium filter are typically performed at 28 kVp using about 6 cm of uniform phantom material Due to the challenges of mass producing 0 025 mm rhodium filters nearly every filter can produce visible artifacts if imaged at sufficiently low kVp Note If you have never seen the mottled appearance of a non uniform filter rhodium or molybdenum perform the artifact
79. y 2 button LED and LCD label Exposure Button single stage switch Figure 2 Operator Control Panel The Diamond Operator Control Panel uses an LCD display and 7 segment alphanumeric and LED indicators to communicate status information as well as various buttons to regulate the functions of the X ray unit The control panel can be attached to the radiation shield or remotely in a control booth for example An X Ray Exposure can only be initiated from the Exposure Button When it is pressed the computer responds and starts an exposure routine but when it is released the hardware itself terminates the exposure a safety consideration Behavior of the Function Keys will vary depending on the menu display and required functions They are used to choose various imaging modes to select the Integrated Quality Control IQC function and to input date time and hospital information Use the Cancel button to go back one step in the menu without selecting an option or to cancel a selection Use the SET button to accept selections and to proceed to the next step in the menu MM03341b 5 IAS TRUER TARA imaging A MEDICAL PHYSICIST S GUIDE TO DIAMOND GETTING FAMILIAR WITH DIAMOND 3 Positioning Control Centre Collimator Lamp Button Compression Force Selector Filter Selector Rotate Control 1 CCW 2 CW patient view AutoPoint Detector On Off Manual Detector Selector Thickness Display cm Force Di
80. y detector the actual signal strength produced by each one By performing repetitive identical tests using all 8 detectors and m 20M DETECTOR DETECTOR ARRAY L1 SELECTION 20M DETECTOR gt E SIGNAL OUT a DETECTOR ARRAY C1 DETECTOR ARRAY R1 DETECTOR ARRAY 12 DETECTOR ARRAY C4 4 C DETECTOR ARRAY C3 DETECTOR ARRAY 22 ________ 3 v DETECTOR ARRAY C2 L R Figure 27 AutoPoint Detector Design comparing the results the inspector can identify the detector with the most variation in readings and perform all subsequent testing using that one detector It follows that if the equipment produces acceptable results using the detector with the greatest coefficient of variation then the remaining seven detectors will also produce acceptable results Extensive testing in the factory supports this premise E AEC PERFORMANCE EVALUATION 1 Background MM03341b Despite Diamond s multi detector design evaluating the AEC system is straightforward process The recommendations and procedure that follow were designed to minimize the number of exposures that must be taken and yet be thorough enough to effectively appraise the AEC performance according to MQSA requirements Instrumentarium Imaging recommends that the inspector check all combinations of Configuration Mode and Detector according to method 2 as described in the MQSA Policy

A Medical Physicist`s Guide to Diamond

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