Case TAVR080: Aortic Valve step-by-step guide

Transcription

1 Case TAVR080: Aortic Valve step-by-step guide 3D printing the aortic valve M-0635B

2 Case Airways - Learning objectives At the end of the session, the student will be able to: Use and refine automatic segmentation. Aorta/TAVR using the generic Vitrea tools such as Sculpt, Visible Pick with HU thresholding (using WL). Generate, verify and improve a region shell as aortic root wall and aortic valve (partial) model. Generate a.stl mesh model of the aorta wall, preview the model in 3D and MPR viewers, and save the model on disk. Reuse the.stl aortic wall model in an external software (Meshmixer*). Visualize the.stl model and improve the model using Sculpting tools. Apply a cut plane on the model, analyze the model, its dimensions, strength, orientation, modify the orientation and location for printing. Export the modified.stl file, prepare for 3D printing, select printer Perform the segmentation of the calcium in the aortic wall and export it as.stl file. *All third party marks are property of their respective owners.

3 Select Case TAVR 080 first series (). Load volume (). 3

4 Select Vascular TAVR CT (). TAVR protocol (). 4

5 Check automatic segmentation (). Tint/MPR vessel region (). Let s restrict the future 3D model to the aortic root. 5

6 Improve auto segmentation: select Sculpt tool (). Contour the aortic root (). AddTo the selection as a new region renamed as Aortic root (3). 3 Tip: In 3D, press and hold the left mouse button to get the sculpt tool or press the Alt. key. 6

7 Tint/MPR the aortic root region (). The leaflets are included in the lumen (). Let s apply a new window level in 3D for thresholding: example type W and 380 L for /400HU WL (3). 3 7

8 Select the Visible Pick tool (under Organ Pick) (). Click in 3D aortic root (). Check in MPR that the light blue selection excludes the leaflet and soft tissue but keeps the lumen (3). Otherwise choose a new WL - thresholding. AddTo to a new region (Aortic Root ) (4)

9 You can select Show Volume region menu () to see the segmented root in solid colors. Let s now create a shell region representing the aortic wall. Tip: The thresholding will not exclude all soft tissue. For more precise editing, use sculpt tool in MPR, the livewire and the interpolation reduces the user workload. Pen based monitors such Wacom Cintiq are compatible with Vitrea and great tools for manual model repairs. 9

10 Select AorticRoot (). Select Create Shell (). 0

11 Type a shell thickness larger than the slice thickness (). Here:.4 mm. OK (). Tip: The preview is optional and seen in other tutorials

12 The region shell has been created (). Apply Show Volume for visualization (). We need to open the top and bottom ends of the aorta wall region (3). 3 3

13 Select Sculpt tool (). Draw in 3D a contour to exclude the top and bottom of the aorta (). Click Remove (or equivalently AddTo Base = non segmented) (3). 3 Reminder: In 3D, press and hold the left mouse button to get the sculpt tool or press the Alt. key 3

14 We can now export the aortic root shell as a mesh model (.stl) (). 4

15 Choose export quality 3 () and click Preview (). Tip: Export quality is related to the number of triangles of the final model. For this small precise model, 3 is a good compromise quality/file size. 5

16 Select directory to save the.stl file (). OK (). Tip: you can create a new directory using the top bar standard button. 6

17 The.stl file has been saved. 7

18 Editing the 3D model Use of Meshmixer software is for demonstration purposes only

19 Open Meshmixer and import the mesh model. 9

20 Import the 3D model (.stl) using Meshmixer. 3D rotation: mouse wheel button Zoom = alt + right mouse button Pan: alt + mouse wheel 0

21 Let s repair the model with the Sculpt tool. Choose Shrink smooth brush or Flatten brush (). Choose best brush size and strength (). Flatten bumps in the 3D model (3). 3 3D rotation: right mouse button Zoom = alt + right mouse button Pan: alt + mouse wheel

22 Apply cut plane: Select Edit menu Plane cut.

23 Smooth edge cut plane: Use Sculpting tools. Choose Shrink smooth brush or Flatten brush (). Choose best brush size and strength(). Make smoother edges in the 3D model (3). 3 3

24 Analyze the model check mesh defects. Here the model is ok. 4

25 Analyze the model orient model for printing, adjust settings, update or accept. 5

26 Analyze the model after model positioning on the printer tray 6

27 Example of 3D printing result with flexible material. 3D printed with Stratasys Objet Connex series ** Aortic wall: Rubber-like translucent (TangoPlus FLX930) Shore? Calcium: Rigid opaque white material (VeroWhitePlus) **All third party marks are property of their respective owners. 7

28 Adding the calcified wall lesions

29 Our case contains a single calcium spot adjacent to the segmented wall (shell). 9

30 Select only the aortic lumen region containing the calcium spot (). Right click menu: Show segmentation. On () Define a WL threshold keeping the calcium (try several values: here WL = /540HU). 30

31 Select Visible pick tool (). Click on the calcium spot (). 3

32 Dilate X (), AddTo Calcium region (rename it) () 3

33 A new Calcium region has been created (). 33

34 Export the calcium region () as.stl (). 34