1. 4-6-2016Diffusion Use Case1 Diffusion in Brain IHE use case for Enhanced MR

2. 4-6-2016Diffusion Use Case2 Description This use case refers the MR procedure of standard Diffusion Weighted Imaging (DWI) or Diffusion Tensor Imaging (DTI), in which stacks of images (slices) are generated with different meaning and derived contrast. The images are present in different Enhanced MR SOP Instances: 1.There shall be a series of original images with different Diffusion b-values. There shall be a stack of images for b=0. For other b-values there may be a number of images for different diffusion gradient directions. 2.There shall be a series with the resulting isotropic images (at least for b=max) 3.If there are ADC images then there shall be a series with ADC images for each slice (at least for b=max) The isotropic images and ADC images for b = max shall be presented in conjunction with the b=0 images for each slice. This use case defines that non-isotropic images (which only differ by Gradient Direction) may be present, but are not of interest for standard viewing applications (these images may be specific for Diffusion postprocessing like FiberTracking).

3. 4-6-2016Diffusion Use Case3 Notes All images are related to their respective InStackPositionNumber. These numbers (and their dimension indices) are to be kept consistent over all related Enhanced MR Objects through the Dimension Organization. b=0 Images are related to only one b-value (=0) Isotropic images are one-to-one related to a b-value. They are the result of a postprocessing on the directional images of one slice for one b-value, these original images may or may not be present in the “original” object. ADC images are the result of a postprocessing on the (isotropic or the original directional) images of one slice for different b-values. Reference shall be made to the source image SOP Instances.

4. 4-6-2016Diffusion Use Case4 b=0 ISO ADC Display example Series navigation scroll b=0 Slice 1 b=0, Slice 3 b=0 Slice 2 b=max ISO Slice 1 b=max ISO Slice 3 b=max ISO Slice 2 ADC for b=max Slice 1 ADC for b=max Slice 3 ADC for b=max Slice 2 Linked by position

5. 4-6-2016Diffusion Use Case5 Selection Criteria for the use case (all apply) SOP CLASS UID is: Enhanced MR Image  ======== Image Type and Frame Type have: –Value 1: ORIGINAL for b=0 and Directional DERIVED for Isotropic and ADC –Value 2: PRIMARY –Value 3: DIFFUSION  ============ –Value 4: for “ORIGINAL” “ISOTROPIC” for Isotropic of DW-TRACE “ADC” for ADC maps: ADC-TRACE For diffusion images (= all images in this use case) the “Per Frame Functional Groups Sequence” contains the “MR Diffusion Sequence”.

6. 4-6-2016Diffusion Use Case6 SOP Instance content b=0 b>0 direction 1 b>0 direction.. b>0 direction n Isotropic ADC SOP 1 ORIGINAL x b-values, y slices+ n directionals SOP 2 DERIVED x-1 b-values, y slices SOP 3 DERIVED x-1 b-values, y slices

7. 4-6-2016Diffusion Use Case7 Image Type and Frame Type Values for original images in this use case ImageFrame Content content Original scan b=0 slices gradient directions Value 1 ORIGINAL Value 3 DIFFUSION Value 4 -- -

8. 4-6-2016Diffusion Use Case8 Example of Image Type and Frame Type Values for Isotropic images in this use case ImageFrame Content content Isotropic series Isotropic images Value 1 DERIVED Value 3 DIFFUSION Value 4 “ISOTROPIC”

9. 4-6-2016Diffusion Use Case9 Example of Image Type and Frame Type Values for “ADC” images in this use case ImageFrame Content content ADC series ADC Value 1 DERIVED Value 3 DIFFUSION Value 4 ADC

10. 4-6-2016Diffusion Use Case10 Object requirements for creators Creator provide Enhanced MR Image SOP instances with dimension indices for: 1.Stack ID 2.InStackPositionNumber 3.Diffusion b-value (new IHE Use Case Requirement: to sort on increasing value) Index values are to be given according increasing b-value

11. 4-6-2016Diffusion Use Case11 Object Relations Derivation Image Sequence –Refers to the method used for derivation. Codes to be used for Image Derivation: CID 7203 –Isotropic: Diffusion weighted : 113043 –ADC: Apparent Diffusion Coefficient: 113041 Source Image Sequence –Refers to the SOP Instance of the source images SOP Instance UID of the source Dimension Organization UID shall have one overall value in the use case.

12. 4-6-2016Diffusion Use Case12 Functional Requirements for Display 1.Support Enhanced MR SOP Class. 2.Support the use of Derivation Image Functional Group for tracking the original images (standard DICOM). 3.Support the display according the Image Dimensions. 4.Provide (at least) one row of three viewports for the display of frames for the same InStackPositionNumber (= slice number). Minimally the frames with b=0 and an Isotropic for b=max and the ADC image for b=max should be displayed. 5.The frames of one InStackPositionNumber must be presented in one row. Additional rows can be used for other InStackPositionNumber-s. 6.Be able to filter (select) frames based on Diffusion Directionality attribute as described in the profile. 7.Be able to scroll the images (vertically) by InStackPositionNumber-Index.

13. 4-6-2016Diffusion Use Case13 Frame # StIDInSt pos b-value Directionality 1111None 2112directional 3112 4112 5112 6112.. 12121None 13122directional 14122directional.. x143directional 1 stack 4 slices 3 b-values 5 directions SOP Instance 1 “originals” Display Rule is: Select only frames with Diffusion Directionality = NONE i.e. equivalent to Select only frames with 3 rd index (b-value index) =1 Sort frames according increasing InStackPositionNumber index. Example Dimension index values example Display (frame#) b=0b=maxADC 121 1242 2363 3484 Note: frames may be stored in random order !

14. 4-6-2016Diffusion Use Case14 SOP Instance 3: ADC Images only for b=max Display (frame#) Display Rule is: Select only image with highest b- value index. Sort frames according increasing InStackPositionNumber index. Display the values of the dimension attributes with each frame. Frame # StIDInSt pos b- valu e 1113 2123 3133 4143 Frame # StIDInSt pos b- valu e 1112 2113 3122 4123 SOP Instance 2: Isotropic Images of all b-values >0 Dimension index values example (cont’d) b=0b=maxADC 121 1242 2363 3484

15. 4-6-2016Diffusion Use Case15 (CLOSED) Open issues It must be discussed in WG16 whether the Isotropic images generated in the reconstruction process can indeed still be called “ORIGINAL” images. (ISOTROPICS are DERIVED) It must be discussed in WG16 whether Isotropic images when called: “DERIVED”, shall have their own defined term for Frame type Value 4. “ISOTROPIC” => DICOM CP It must be discussed in IHE, whether the allocation of certain Index Values may be prescribed for otherwise unsorted attribute values ( e.g. b-value: DICOM allows free allocation of index values). YES, b-values shall be indexed according increasing b-value.

16. 4-6-2016Diffusion Use Case16 End case

17. 4-6-2016Diffusion Use Case17 Dimension Organization 6 1 1 5 UID=1 Dim 1 Dim 2 6 1 1 5 UID=1 Dim 1 Dim 2 8 1 5 UID=1 UID=2 1 Dim 1 Dim 2 5 x 6=30 frames 5 x 8=40 frames