1. 1 DICOM WG-02 Advances in X-Ray Angiography Projection Imaging and 3D SPIE Medical Imaging 2009, Orlando Authors: Tim BeckerEuropean Society of Cardiology Heinz BlendingerSiemens Healthcare Bas Revet Philips Healthcare Francisco Sureda GE Healthcare (Speaker) Rainer Thieme Siemens Medical Solutions (Chair DICOM WG-02)

2. 2 Introduction Present and future of X-Ray Angiography in DICOM 2D Projection Images & Presentation Application Cases of the Enhanced XA SOP Class XA 2D Grayscale Softcopy Presentation State 3D Reconstruction from Projections & Presentation X-Ray 3D SOP Class N-Dimensional Grayscale Softcopy Presentation StateConclusion Presentation Outline

3. 3 Overview of X-Ray Angiography in DICOM 2D Projection Images X-Ray Acquisition 3D Reconstruction Approved in the Standard Work in Progress Supp 94: Radiation Dose Reporting Supp 83: Enhanced XA/XRF Supp 116: X-Ray 3D Storage Supp 139-PC: Enhanced XA Informative Annex Supp 140-PC: Presentation State Follow-up of PAS by IEC MT38 – 62B Multi-Dimensional Presentation State Follow-up of IHE REM Profile

4. 4 Workflow 2D X-Ray Angiography 2D Visualization System X-Ray Acquisition System X-Ray Acquisition Procedure X-Ray 2D Projection SOP Class Visualization SOP CLASS Visualization Presentation Procedure 2D Presentation State SOP Class SOP CLASS

5. 5 Supplement 83 – Standard 2004 –New SOP Class for Multi-frame X-Ray Projection Angiography –Re-use of encoding mechanisms of Enhanced CT and MR –Enhanced with new attributes to support new applications What can be done with this new SOP Class? –Supplement 139 (Part 17 – Informative) – Public Comments passed Describes use cases where the Enhanced XA provides better solutions Provides encoding guidelines for implementors, both creators and users of the Enhanced XA SOP Class Enhanced XA: 2D projection images

6. 6 – General Definitions: Time relationships, Acquisition Geometry, Pixel Size calibration – Application Use Cases Acquisition : Waveform synch, Mechanical Movement, X-Ray controls… Image Registration : 3D structures projected on 2D images Display : Standard pipeline, multi-mask subtraction, per-frame pixel shift Review : Variable review settings per group of frames Processing : Projection pixel calibration Enhanced XA: Supplement 139 X-Ray Acquisition Modality X-Ray 2D Projection Enhanced XA SOP CLASS Applications

7. 7 Acquisition Datetime (0008,002A) Acquisition Duration (calculated) Frame “i” Reference Datetime Frame “N” Reference Datetime Frame “1” Acquisition Duration (0018,9220) Content Date (0008,0023) Content Time (0008,0033) … time … Frame “i” Acquisition Datetime Frame “N” Acquisition Datetime FRAME 1FRAME i FRAME N If Acquisition is synchronized with external time reference then Acquisition Time Synchronized (0018,1800) = YES Exposure Time (0018,9328) = SUMi( Frame “i” Acquisition Duration ) Average Pulse Width (0018,1154) = SUMi(Frame “i” Acquisition Duration) / N Frame “N” Acquisition Duration Frame “1” Acquisition Datetime (0018,9074) Frame “1” Reference Datetime (0018,9151) Enhanced XA – Time Relationships

8. 8 NOTE: Positioner angle values, table position values etc… are measured at the Frame Reference Datetime Frame Acquisition Duration (0018,9220) time Frame Reference Datetime (0018,9151) Frame Acquisition Datetime (0018,9074) R X-ray FRAME “i” Frame Acquisition Number (0020,9156) = “i” PRE-FRAME X-ray Last R-peak prior to the X-ray FRAME “i” Cardiac Trigger Delay Time (0020,9153) Q S T Detector Active Time (0018,7014) Detector Activation Offset from Exposure (0018,7016) Enhanced XA – Time Relationships (one frame)

9. 9 Enhanced XA – Acquisition Techniques Values per frame are in the Per-frame Functional Groups Seq. (200,9230): In the Frame Content Sequence (0020,9111): –Frame Acquisition Duration (0018,9220) in ms of frame « i » =  t i In the Frame Acquisition Sequence (0018,9417): –KVP (0018,0060) of frame « i = kVp i –X-Ray Tube Current in mA (0018,9330) of frame « i » = mA i

10. 10 PATIENT position on the Table TABLE movement POSITIONER movement Detector Binning FOV Rotation & Horiz Flip System set upImage Transformation X-Ray Acquisition Patient Position Description X-Ray Table Description X-Ray Positioner Description FOV Description Pixel Data Storage Detector Description Enhanced XA – Acquisition Geometry  X-Ray Isocenter Reference System Macro  X-Ray Geometry Macro  X-Ray Field of View Macro  XA/XRF Acquisition Module  X-Ray Detector Module  Image Pixel Module

11. 11 Acquisition #1 Enhanced XA – 3D/2D Registration P 1t (x t,y t,z t ) f a (P 1, Table 1 ) +Y +Z +X O P 2p (x p,y p,z p ) f c (P 2, Positioner 2 ) Positioner Movement +Y +Z +X O P 2 (x,y,z) f b (P 1t, Table 2 ) Table Movement +Y +Z +X O P 2 (i,j) f d (P 2, SID, ISO, FOV) SID, ISO, FOV change +Xp +Zp +Yp +Y +Z +X O Acquisition #2 P 1 (x,y,z) +Y +Z +X O

12. 12 Enhanced XA – Standard Display Pipeline Stored Values VOI LUTP LUT Display Pixel Intensity Relationship LUT Pixel values transformed for specific application (if TO_LINEAR, then pixel values proportional to the X-ray beam intensity) Pixel Intensity Relationship LUT Sequence (0028,9422) Application Pixel Intensity Relationship LUT Pixel values transformed for specific application Pixel Intensity Relationship LUT Sequence (0028,9422) 1 to N Application “TO_LINEAR” is required if Pixel Intensity Relationship (0028,1040) = LOG Shape = “IDENTITY” if (0028,0004) = MONOCHROME2 Shape = “INVERSE” if (0028,0004) = MONOCHROME1 X Modality LUT

13. 13 Enhanced XA – Variable Review Settings FRAME ACQUISITION: DICOM ENCODING: XA/XRF Multi-frame Presentation Module Frame Display Sequence (0018,7022) 1234 Acq. Frame rate: 4.0 Purpose: X-Ray control 5 Item 1 >Start Trim (0008,2142) >Stop Trim (0008,2143) >Skip Frame Range Flag (0008,9460) >Recom. Display Frame Rate (0008,9459) = 1 = 5 = SKIP = 4.0 6789 Acq. Frame rate: 15.0 Purpose: Contrast Media 10111213 Item 2 >Start Trim (0008,2142) >Stop Trim (0008,2143) >Skip Frame Range Flag (0008,9460) > Recom. Display Frame Rate (0008,9459) = 6 = 13 = DISPLAY = 15.0 14151617 Acq. Frame rate: 8.0 Purpose: Contrast Media 1819 Item 3 >Start Trim (0008,2142) >Stop Trim (0008,2143) >Skip Frame Range Flag (0008,9460) > Recom. Display Frame Rate (0008,9459) = 14 = 19 = DISPLAY = 8.0

14. 14 Mask Subtraction Sequence (0028,6100) #1 #2 #3 Frames DICOM ENCODING: Mask Module FRAME ACQUISITION and PROCESSING: Item 1 >Mask Operation (0028,6101) >Subtraction Item ID (0028,9416) >Applicable Frame Range (0028,6102) >Mask Frame Numbers (0028,6110) >Mask Operation Expl. (0028,6190) = AVG_SUB = 100 = 2\3 = 1 = Left leg Left Leg Sub ID 100 Enhanced XA – Pixel Shift per frame Item 2 >Mask Operation (0028,6101) >Subtraction Item ID (0028,9416) >Applicable Frame Range (0028,6102) >Mask Frame Numbers (0028,6110) >Mask Operation Expl. (0028,6190) = AVG_SUB = 101 = 2\3 = 1 = Right leg Right Leg Sub ID 101

15. 15 Item 2 >Frame Pixel Shift Seq (0028,9415) Item 3 >Frame Pixel Shift Seq (0028,9415) Frame #2 Frame #3 Frames Enhanced XA – Pixel Shift per frame #1 #2 #3 DICOM ENCODING: Frame Pixel Shift per frame FRAME ACQUISITION and PROCESSING:

16. 16 Item 2 >Frame Pixel Shift Seq (0028,9415) Item 3 >Frame Pixel Shift Seq (0028,9415) Frame #2 Frame #3 Frames Enhanced XA – Pixel Shift per frame #1 #2 #3 Item 1 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 100 = 0.0\8.0 Item 1 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 100 = 2.0\10.0 Left Leg mask Pixel Shift 8.0 0.0 \ 8.0 Pixel Shift 2.010.0 2.0 \ 10.0 DICOM ENCODING: Frame Pixel Shift per frame FRAME ACQUISITION and PROCESSING:

17. 17 Item 2 >Frame Pixel Shift Seq (0028,9415) Item 3 >Frame Pixel Shift Seq (0028,9415) Frame #2 Frame #3 Item 2 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 101 = 0.0\0.0 Item 2 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 101 = 0.0\-7.0 Right Leg mask Pixel Shift 0.0 \ 0.0 Pixel Shift -7.0 0.0 \ -7.0 Frames Enhanced XA – Pixel Shift per frame Item 1 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 100 = 0.0\8.0 Item 1 >>Subtraction Item ID (0028,9416) >>Mask Sub-pix Shift (0028,6114) = 100 = 2.0\10.0 Left Leg mask Pixel Shift 8.0 0.0 \ 8.0 Pixel Shift 2.010.0 2.0 \ 10.0 #1 #2 #3 DICOM ENCODING: Frame Pixel Shift per frame FRAME ACQUISITION and PROCESSING:

18. 18 D = # Px *  Px * SOD / SID SOD = ISO- (TH-TO) / cos°(Beam Angle) Enhanced XA - Projection Pixel Size Calibration #Px = Object size in “image” pixels D = Object size in mm TH = Table Height (0018,1130) TO = Dist. Table to Object (0018,9403) Beam Angle(0018,9449) SID = Dist. Source-Detector(0018,1110) ISO = Dist. Source-ISO(0018,9402)  Px = Imager Pixel Spacing(0018,1164) How to convert from “image pixels” to “object mm in patient”

19. 19 XA/XRF Projection Presentation State

20. 20 Supplement 140: new XA GSPS IOD (for 2D) Information that may be used to present angiographic projection images It includes capabilities from the Grayscale Softcopy Presentation IOD for specifying: a. the output grayscale space in P-Values b. grayscale contrast transformations including VOI LUT c. selection of the area of the image to display, rotate, flip d. image and display relative annotations, graphics, text and overlays

21. 21 Supplement 140: new XA GSPS IOD (for 2D) Specific capabilities are provided for the presentation of angiographic projection images: shutterframe-by-frame a. shutter specifications on a frame-by-frame base, mask subtractionregional pixel shift b. mask subtraction including regional pixel shift sets of frames c. presentation of sets of frames Similar to the XA/XRF Multi-Frame Presentation Module of the Enhanced XA/XRF

22. 22 XA Grayscale Softcopy Presentation State  Shutter per frame The shutter coordinates per-frame may be modified in post-review Frame #1 Frame #2 Frame #3 Frame #4 Frame #5  Grayscale Contrast Transformations The sequence of transformations from stored pixel values into P-Values is explicitly defined in a conceptual model

23. 23 XA Grayscale Softcopy Presentation State  mask subtraction & regional pixel shift Contrast Frame(s) Mask Frame(s) « TO_LOG » LUT If Pixel Intensity Relationship is not LOG If Pixel Intensity Relationship is not LOG « TO_LOG » LUT Pixel Shift & Anatomic Background Visibility Pixel Shift & Anatomic Background Visibility SUB VOI LUT … Else

24. 24 XA Grayscale Softcopy Presentation State  Regional pixel shift Applicable pixel shift in case of multiple pixel shift regions

25. 25 Sup 140 – Example of Regional Pixel Shift Mask frame: non-injected structures (bones, soft-tissues…)

26. 26 Sup 140 – Example of Regional Pixel Shift Contrast frame: injected vessels – background structures moved since the mask acquisition

27. 27 Sup 140 – Example of Regional Pixel Shift Subtraction without pixel shift: background structures are visible

28. 28 Sup 140 – Example of Regional Pixel Shift Regional Pixel Shift: Select region 1

29. 29 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Mask Pixel Shift (Row) Regional Pixel Shift: Apply shift to mask on region 1

30. 30 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Mask Pixel Shift (Row)

31. 31 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Mask Pixel Shift (Row)

32. 32 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Mask Pixel Shift (Row) … until background structures are not visible anymore

33. 33 Sup 140 – Example of Regional Pixel Shift Regional Pixel Shift: Select region 2

34. 34 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Regional Pixel Shift: Apply shift to mask on region 2

35. 35 Sup 140 – Example of Regional Pixel Shift Regional Pixel Shift: Select region 3

36. 36 Sup 140 – Example of Regional Pixel Shift Mask Pixel Shift (Column) Regional Pixel Shift: Apply shift to mask on region 3

37. 37 Sup 140 – Example of Regional Pixel Shift Subtraction with regional pixel shift: background structures are not visible anymore

38. 38 3D X-Ray Angiography

39. 39 Workflow 3D X-Ray Angiography 3D Reconstruction System X-Ray Calibration Procedure Calibration Data Proprietary X-Ray Acquisition System 3D Visualization System X-Ray Acquisition Procedure X-Ray 2D Projection SOP Class SOP CLASS 3D Storage SOP Class Reconstruction Procedure Visualization SOP CLASS Visualization Presentation Procedure 3D Presentation State SOP Class In progress

40. 40 Supplement 116 – In standard 2007 –New SOP Class for Multi-frame X-Ray 3D from projections –Re-use of encoding mechanisms of Enhanced CT and MR –Re-use volumic descriptions of Enhanced CT and MR –Additional information of the reconstruction from projections What can be done with this new SOP Class? –Basic 3D visualization (slices) –References to 2D projections –Description of the reconstruction application –Relationship to the Equipment Coordinate System –... X-Ray 3D Angiography

41. 41 X-Ray 3D Angiography – Rotational Acquisition Frame #5: X-ray settings 5 Geometry settings 5 Frame #2: X-ray settings 2 Geometry settings 2 Frame #3: X-ray settings 3 Geometry settings 3 Frame #4: X-ray settings 4 Geometry settings 4 Frame #1: X-ray settings 1 Geometry settings 1 Optimized 3D Reconstruction

42. 42 X-Ray 3D Angiography – Reference to 2D 2D Projection SOP Instance «A» M1......M2 Mask Contrast C1......C2 X-Ray 3D SOP Instance 1......N Mask Reconstruction 1...N+kN+1... SUB Reconstruction 2 Contributing Sources Contributing Sources Sequence (0018,9506) SOP Instance description Contributing Sources Contributing Sources Sequence (0018,9506) SOP Instance description Acquisition X-Ray 3D Acquisition Sequence (0018,9507) Acquisition description Acquisition X-Ray 3D Acquisition Sequence (0018,9507) Acquisition description Reconstruction X-Ray 3D Reconstruction Sequence (0018,9530) Reconstruction description Reconstruction X-Ray 3D Reconstruction Sequence (0018,9530) Reconstruction description Per-Frame Per-Frame Func Groups Sequence (5200,9230) Frame description Per-Frame Per-Frame Func Groups Sequence (5200,9230) Frame description Recon #2: Acquisition Index = 1\2 Frames #N+1 to #N+k: Recon Index = 2 Acq #2: Source Img Seq = A: C1 to C2 Acq #1: Source Img Seq = A: M1 to M2 Recon #1: Acquisition Index = 1 Frames #1 to #N: Recon Index = 1 = SOP Inst “A” Source #1: Contrib. SOP Inst

43. 43 X-Ray 3D Angiography - Relationship to Equipment Patient Oriented Coordinate System of the 3D slices P ( B x, B y, B z) Image to Equipment Matrix (0028,9520) Enhanced XA: Isocenter Reference System Equipment Coordinate System of the 2D projections P ( A x, A y, A z) +Y +Z +X O

44. 44 X-Ray 3D Angiography Presentation State

45. 45 X-Ray 3D Angiography – Presentation State Needs for 3D Angiography Presentation – Presentation features common to all 3D – Speficic presentation of X-Ray 3D Angiography: Acquisition 3D shutter for collimation Volume Subtraction and voxel shift Stabilized point in all volumes (e.g. cardiac wall motion, stent stabilized) Catheter tracking trajectory in one volume 2D-3D blending presentation (3D conic projection on 2D fluoroscopy) N-Dimensional Presentation State Work Item 2008-04-C. Addresses needs of multi-modalities Led by Working Group 11, participation of Web3D and other working groups Supplement in progress...

46. 46Conclusion Supplement 139 – Enhanced XA application cases In Public Comments. Informative (DICOM Part 17) Will facilitate the adoption of the Enhanced XA (Sup 83) Supplement 140 – XA/XRF Presentation State In Public Comments. Enables: shutter on a frame-by-frame base, mask subtraction including regional pixel shift presentation of set of frames X-Ray 3D Angiography New IOD approved in Standard 2007 (Sup 116) 3D Presentation State on-going... Contact WG-02 chairman: francisco.sureda@med.ge.com