8/3/2011. Implementation Status. Yes (EI and DI) On all new equipment Legacy systems can be upgraded (digitizer (plate reader) upgrade not required).

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1 Exposure Indices: S. Jeff Shepard, MS, DABR, FAAPM Imaging Physics Department Diagnostic Imaging Division The University of Texas M. D. Anderson Cancer Center Houston, Texas AAPM 2011 Imaging Education Radiography III Charge: Introduction How is industry progressing in adoption of IEC Ed. 1? Who is adopting recommended TG116 features? To what extent? Outline: Review TG116 recommended features Aimed and performance tests and QC t covered in IEC standard The Survey response details 2 Implementation Survey 1. Please describe your company s exposure index and deviation index. 2. If you do not display an exposure index, is your company in the process of developing an index of detector exposure after every image? 3. Does your company s exposure index conform to the definitions in IEC Ed. 1? 4. If not, what do you call your exposure index and what symbol do you use for it? What are the units of your exposure index? The relationship between radiation conditions (ie dose or exposure) at the detector and the exposure index Standard beam conditions under which the index is defined 5. Do your DR products currently provide an index equivalent to the Deviation Index described in IEC Ed. 1 immediately after every exposure? 6. If not, is your company in the process of developing an index that provides feedback information to the technologist user about the adequacy of the exposure? 3 1

2 Implementation Survey 7. What do you call your Deviation Index and what symbol do you use for it? 8. Do you provide other forms of feedback to the technologist user about the adequacy of the exposure (color bars, thermometers, etc)? 9. What default target EI s have you established and how does the user selectively change these values? 10. Has your company implemented storage and transmission of the EI and DI information in the DICOM header of the image? (EI: (0018,1411), EI TGT : (0018,1412), and DI: (0018,1413)). 11. What is the number of significant digits your company uses for EI and DI? 12. Is the Deviation Index (DI) recalculated and displayed immediately after any modification of the detected image VOI by the operator? 13. Is the display of segmented image pixels possible? 14. Can the segmented region be saved as an overlay and images be exported for archival or viewing using DICOM services? 4 Implementation Survey 15. Is access to images containing for-processing pixel values (Q) possible on the console or through export using DICOM media storage? 16. Is the relationship between QK values and the standardized radiation exposure incident to the DR detector for tests of system performance provided to the user? 17. Is display of images without image processing (i.e., Q values) to report the mean, median, mode, standard deviation, and pixel count of values within graphically defined d regions possible? 18. Can the anti-scatter grid be removed for calibration? 19. Can the KTGT values be imported and exported? 20. Are logs of the DI values and logs of the reasons for rejected and repeated images stored on the system? Are the rejected images stored on the system? Do you provide software to analyze the logs? Can the logs be accessed over a network from a remote location? In what file format are the logs kept? 5 Implementation Survey 10 s Invited Healthcare Health USA Healthcare Konica-Minolta Medical Systems Medical Systems Swissray 8 responded Healthcare Health USA Medical Systems Medical Systems 6 2

3 Do your indices conform to IEC Ed. 1? (EI and DI) On all new equipment Legacy systems can be upgraded (digitizer (plate reader) upgrade not required). Many legacy versions exist (RD, REX) none are IEC compliant. Latest (v 8.0) 80) is compliant with EI only. If desired, d newer NE software displays IEC compliant EI, and DI if EI T s are entered., but new equipment will support IEC by Legacy EI will still be an option. Both a proprietary index and the IEC exposure indices are offered. IEC indices (EI and DI) comply. Either or both may be displayed. Proprietary index is S which does not comply with IEC. Do your indices conform to IEC ed. 1? (EI and DI) On all new equipment Legacy systems can be upgraded (digitizer (plate reader) upgrade not required). Many legacy versions exist (RD, REX) none are IEC compliant. Latest (v 8.0) 80) is compliant with EI only. If desired, d newer NE software displays IEC compliant EI, and DI if EI T s are entered., but new equipment will support IEC by Legacy EI will still be an option. Both a proprietary index and the IEC exposure indices are offered. IEC indices (EI and DI) comply. Either or both may be displayed. Proprietary index is S which does not comply with IEC. Do your indices conform to IEC? (EI and DI) 2011 and later. Earlier products as described in TG116 Appendix (CDExp and UDExp). Does not apply to derived images (DES or Volume Rad).. Std beam does not conform. Estimated Plate Dose is equivalent to EI, but not compliant. Legacy index equivalent to DI but is called EI. Working on changing this. (EI only) Eleva-based only (Digital Diagnost, PCR). Legacy equipment will not support. DI yet. (EI only) - On new equipment (YSIO, Luminos drf and Luminos Agile). Legacy equipment will not support. DI yet. 3

4 Do your indices conform to IEC? (EI and DI) 2011 and later. Earlier products as described in TG116 Appendix (CDExp and UDExp). Does not apply to derived images (DES or Volume Rad).. Estimated Plate Dose is equivalent to EI, but not compliant. (Std beam does not conform.) Legacy index equivalent to DI but is called EI. Working on changing this. (EI only) Eleva-based only (Digital Diagnost, PCR). Legacy equipment will not support. DI yet. (EI only) - On new equipment (YSIO, Luminos drf and Luminos Agile). Legacy equipment will not support. DI yet. TG116 Recommended Features Target EI determination IEC: EI T (b,v) tables to be established by professional societies or by the Responsible Organization (IEC :2005, 1:2005, 3.101) TG116: Established by the system administrator or the equipment manufacturer Defaults provided by vendor as a starting point and then modified by the users to suit their preferences for noise content. 11 Tools for Target EI Defaults Will be provided by July 2011, default target = 876 (Equivalent to S = 200, undergoing clinical review). Check with your representative for current default target values. Edits Input by service engineer, key operator, or sys admin. NX workstation can automatically assign average of 50 exam views as target. User sets all EI T values via manual entry. Intended for manual customization by end user. EI T may be changed in the user utility. 4

5 Tools for Target EI Defaults Will be provided by July 2011, default target = 876 (Equivalent to S = 200, undergoing clinical review). Check with your representative for current default target values. Edits Input by service engineer, key operator, or sys admin. NX workstation can automatically assign average of 50 exam views as target. User sets all EI T values via manual entry. Intended for manual customization by end user. EI T may be changed in the user utility. Tools for Target EI Defaults Will be provided by July 2011, default target = 876 (Equivalent to S = 200, undergoing clinical review). Check with your representative for current default target values. Edits Input by service engineer, key operator, or sys admin. NX workstation can automatically assign average of 50 exam views as target. User sets all EI T values via manual entry. Intended for manual customization by end user. EI T may be changed in the user utility. Target EI determination Defaults provides default Target EI values. Target plate exposure values are provided by. Edits Intended for manual customization by end user. Target plate exposure values are The user cannot change the target values NA NA Maximum and minimum clinical EXI values can be defined in very organ program via selection of a parameter subset. 5

6 Target EI determination Defaults provides default Target EI values. Target plate exposure values are provided by. Edits Intended for manual customization by end user. Target plate exposure values are The user cannot change the target values NA NA Maximum and minimum clinical EXI values can be defined in very organ program via selection of a parameter subset. Target EI determination Defaults provides default Target EI values. Target plate exposure values are provided by. Edits Intended for manual customization by end user. Target plate exposure values are The user cannot change the target values NA NA Maximum and minimum clinical EXI values can be defined in very organ program via selection of a parameter subset. Target EI determination Defaults provides default Target EI values. Target plate exposure values are provided by. Edits Intended for manual customization by end user. Target plate exposure values are The user cannot change the target values NA (pending future roll-out) NA (pending future roll-out) Maximum and minimum clinical EXI values can be defined in very organ program via selection of a parameter subset. 6

7 TG116 Recommended Features Use graphics to enhance reporting of DI Sliding bar Color-coded tools (Thermometer) VOI histogram with limits indicated

8 Graphical Feedback for DI - Displayed numerically and in graphical form using a color bar. The length of the bar increases as the Deviation Index increases or decreases from 0. Green, Yellow or Red depending on difference from 0. Histogram chart displayed. (Limits?) DI message turns Red. and Pop-up notification if EI Limits established and exceeded. DI displayed as a number placed within a bar consisting of 5 segments (4 user-customizable thresholds, inner and outer). The segment color is GREEN for DI within the inner thresholds, ORAN otherwise. A message is also displayed (customizable) by segment.. Acceptable is Green, unacceptable is Red (high or low). Graphical Feedback for DI - Displayed numerically and in graphical form using a color bar. The length of the bar increases as the Deviation Index increases or decreases from 0. Green, Yellow or Red depending on difference from 0. Histogram chart displayed. DI message turns Red. Pop-up notification if EI Limits established and exceeded. DI displayed as a number placed within a bar consisting of 5 segments (4 user-customizable thresholds, inner and outer). The segment color is GREEN for DI within the inner thresholds, ORAN otherwise. A message is also displayed (customizable) by segment.. Acceptable is Green, unacceptable is Red (high or low). and 8

9 Graphical Feedback for DI - Displayed numerically and in graphical form using a color bar. The length of the bar increases as the Deviation Index increases or decreases from 0. Green, Yellow or Red depending on difference from 0. Histogram chart displayed. DI message turns Red. and Pop-up notification if EI Limits established and exceeded. DI displayed as a number placed within a bar consisting of 5 segments (4 user-customizable thresholds, inner and outer). The segment color is GREEN for DI within the inner thresholds, ORAN otherwise. A message is also displayed (customizable) by segment.. Acceptable is Green, unacceptable is Red (high or low). Graphical Feedback for DI - Displayed numerically and in graphical form using a color bar. The length of the bar increases as the Deviation Index increases or decreases from 0. Green, Yellow or Red depending on difference from 0. Histogram chart displayed. DI message turns Red. and Pop-up notification if EI Limits established and exceeded. DI displayed as a number placed within a bar consisting of 5 segments (4 user-customizable thresholds, inner and outer). The segment color is GREEN for DI within the inner thresholds, ORAN otherwise. A message is also displayed (customizable) by segment.. Acceptable is Green, unacceptable is Red (high or low). Graphical Feedback for DI - Displayed numerically and in graphical form using a color bar. The length of the bar increases as the Deviation Index increases or decreases from 0. Green, Yellow or Red depending on difference from 0. Histogram chart displayed. DI message turns Red. Pop-up notification if EI Limits established and exceeded. DI displayed as a number placed within a bar consisting of 5 segments (4 user-customizable thresholds, inner and outer). The segment color is GREEN for DI within the inner thresholds, ORAN otherwise. A message is also displayed (customizable) by segment.. Acceptable is Green, unacceptable is Red (high or low). and 9

10 TG116 Recommended Features IEC and TG116 call for the indices to change dynamically with manual modification of the VOI after image acquisition Due to failure of VOI recognition 28 Indices change with post- acquisition VOI modification. The user cannot change the VOI., when the exposure menu is changed and the image is reprocessed. with change in electronic collimation (shuttering). Indices change with post- acquisition VOI modification. The user cannot change the VOI., when the exposure menu is changed and the image is reprocessed. with change in electronic collimation (shuttering)., (Will not re-calculate) 10

11 TG116 Recommended Features Tools for verification of proper automated segmentation software result Overlay image of pixels normalized pixel values (Q K ) Export of segmented pixels as an overlay Pop-up display of the For-Processing pixel (Q) histogram with highlighted min and max image pixels 31 Segmentation Verification Tools Segmented pixels can be displayed as overlay? The area outside of the segmented pixels can be masked by a semi-transparent border (adjustable opacity). Exportable? The system will display the region of the image segmented by the black surround mask (basically the x-ray collimated region). (Eventually, yes) (Eventually) Segmentation Verification Tools Segmented pixels can be displayed as overlay? The area outside of the segmented pixels can be masked by a semi-transparent border (adjustable opacity). Exportable? The system will display the region of the image segmented by the black surround mask (basically the x-ray collimated region). (Eventually, yes) (Eventually) 11

12 Segmentation Verification Tools Segmented pixels can be displayed as overlay? The area outside of the segmented pixels can be masked by a semi-transparent border (adjustable opacity). Exportable? The system will display the region of the image segmented by the black surround mask (basically the x-ray collimated region). (Eventually, yes) (Eventually) Segmentation Verification Tools Segmented pixels can be displayed as overlay? The area outside of the segmented pixels can be masked by a semi-transparent border (adjustable opacity). Exportable? The system will display the region of the image segmented by the black surround mask (basically the x-ray collimated region). (Eventually, yes) (Eventually) TG116 Recommended Features Deviation Index Format DI = 0 is supposed to be a perfect exposure, but the precision of the DI (# decimal places) will have impact Round? Truncate? Is +1 really 0.5 or 1.4 (12% or 38% high)? TG116: One digit before/after the decimal to reflect subtle exposure errors and facilitate trend analysis IEC: Undefined 36 12

13 TG116 Recommended Features The DICOM header EI: (0018,1411) EI T : (0018,1412) DI: (0018,1413) DICOM Value Representation is DS (Decimal String) with optional # of characters before/after decimal t all vendors support this 37 Deviation Index Format & DICOM Tag support Format DICOM Tags Supported? 2 digits after the decimal 2 decimal places 2 digits after the decimal 1 digit after the decimal 1 digit after the decimal 3 digits after the decimal Integer (no changes planned) Integer Deviation Index Format & DICOM Tag support Format DICOM Tags Supported? 2 digits after the decimal 2 decimal places 2 digits after the decimal 1 digit after the decimal 1 digit after the decimal 3 digits after the decimal Integer (no changes planned) Integer 13

14 Deviation Index Format & DICOM Tag support Format DICOM Tags Supported? 2 digits after the decimal 2 decimal places 2 digits after the decimal 1 digit after the decimal 1 digit after the decimal 3 digits after the decimal Integer (no changes planned) Integer TG116 Recommended Features Export and import K TGT (EI T ) A process for updating the tables of all systems within a networked system Changes in EI T values readily disseminated to distributed systems Facilitate sharing between imaging facilities using the same DR system 41 Export and Import of EI T Tables. EI T values can be shared between NX modality workstations, too. EI T values can be exported and imported within the protocol database between systems. But there is no provision to independently import or export a table of values... Export, yes. Import,. response (via USB) 14

15 Export and Import of EI T Tables. EI T values can be shared between NX modality workstations, too. EI T values can be exported and imported within the protocol database between systems. But there is no provision to independently import or export a table of values... Export, yes. Import,. response (via USB) Export and Import of EI T Tables. EI T values can be shared between NX modality workstations, too. EI T values can be exported and imported within the protocol database between systems. But there is no provision to independently import or export a table of values... Export, yes. Import,. response (via USB) Export and Import of EI T Tables. EI T values can be shared between NX modality workstations, too. EI T values can be exported and imported within the protocol database between systems. But there is no provision to independently import or export a table of values... Export, yes. Import,. response (via USB) 15

16 Export and Import of EI T Tables. EI T values can be shared between NX modality workstations, too. EI T values can be exported and imported within the protocol database between systems. But there is no provision to independently import or export a table of values... Export, yes. Import,. response NA (pending future roll-out) (via USB) TG116 Recommended Features Tests of system performance and calibration verification in the clinic Removable grid Access to images containing normalized for-processing pixel values On the console Through export using DICOM media storage Images with pixel values linear with exposure For MTF, NPS, and DQE Provide the relationship between Q K and standard exposure if non-linear 47 Tests of system performance and calibration Q K and exposure Removable grid For-processing images at console DICOM Export to Media (upon request), on the NX WS only, from the NX WS only (Log E) (Pattern processing) ROI tools provided, too (Pattern processing, Log E) n responsive Sensitivity value is conversion factor 16

17 Tests of system performance and calibration Q K and exposure Removable grid For-processing images at console DICOM Export to Media (upon request), on the NX WS only, from the NX WS only (Log E) (Pattern processing) ROI tools provided, too (Pattern processing, Log E) n responsive Sensitivity value is conversion factor Tests of system performance and calibration Q K and exposure Future Removable grid Our calibration procedure is done without the use of anti-scatter grid., but calibration is performed with the grid. Forprocessing images at console Future. Physical EI is an indicator of Q K values. DICOM Export to Media response Tests of system performance and calibration Q K and exposure Future Removable grid Our calibration procedure is done without the use of anti-scatter grid., but calibration is performed with the grid. Forprocessing images at console Future. Physical EI is an indicator of Q K values. DICOM Export to Media response 17

18 TG116 Recommended Features Logs of EI/DI values and logs of the reasons for rejected and repeated images Identify potential problematic exams Problems with equipment Technologists in need of coaching Software to analyze the logs to assist with process improvement Enterprise-wide software for centralized data accumulation and analysis For every rejected image, store: Anatomical view selection Technique factor information The image itself 52 DI and Repeat/Reject Logs DI logs stored? Repeat/Reject logs stored?, on the NX modality workstation, on the NX modality workstation, but planned response DI,. EI, DI and Repeat/Reject Logs Software to analyze logs Rejected images stored? provided?, on the NX modality workstation, on the NX workstation (Cache). Can also be exported to a PACS. (RRA function) Jpeg, for 100 days response response 18

19 DI and Repeat/Reject Logs Logs accessible over a Data format network? CMS enables user access to multiple NX workstations for system-wide QC XML (Folder can be shared ) CSV CSV CSV CSV response response Future Proprietary (export as CSV) (USB only) CSV DI and Repeat/Reject Logs Logs accessible over a Data format network? CMS enables user access to multiple NX workstations for system-wide QC XML (Folder can be shared ) CSV CSV CSV CSV response response Future Proprietary (export as CSV) (USB only) CSV Summary IEC EI Conformance Y Y N* Y Y N* Y Y IEC DI Conformance Y Y N* Y Y N* N* N* EI T defaults N N N* Y Y Y NA N* EI T defaults editable Y Y Y Y Y N NA NA Graphical Feedback on DI Y? Y Y Y NA NA NA Recalc Indices after VOI change Y N Y Y Y N NA Y VOI Overlay Y N Y N N N* Y N Export VOI Overlay N N Y N N N* N N DI Format Y Y Y Y Y Y N N DICOM Tags Y N Y Y Y N N Y Export/Import EI T Y? Y Y Y/N? Y Q K vs Exposure Y N Y? Y N* N Y Removable Grid Y Y Y Y Y For-Processing Display Y N Y N Y N* Y N For-Processing Export Y N Y N Y Y Y? DI Logs stored Y N* Y? Y N NA NA Repeat/Reject Logs Y N Y Y Y Y Y Y Rejected Images Stored Y Y Y Y Y? Y Y Log Analysis SW Y N Y Y Y N Y N Log Analysis SW Y N Y Y Y? Y N Logs accessible via network Y N Y N N? N* N CSV Format N Y Y Y Y? Y Y By

20 THANK YOU! Bruce Apgar () Steve Meyer () John (Ian) Yorkston () Bob Uzenoff (, MITA) Kadri Jabri () Abhinav Singh () Ulrich Neitzel () Viola Fernandez () Mike Flynn David Leong Questions? 20