Hello Lassoan,
Is the threshold effect the best tool for segmentation of a 3D printed heart from CT scan images? below you see the segmentation using threshold. I want to produce .vtk or stl. file formats of the endocardial RA, LA, LV and RV from CT images.
TotalSegmentator (GitHub - lassoan/SlicerTotalSegmentator: Fully automatic total body segmentation in 3D Slicer using "TotalSegmentator" AI model) didn’t work properly in this case.
Thanks for your help!
Best
Rahi
TotalSegmentator segments real patient images, which look completely different than the scan of a 3D-printed object. In your 3D object scan, segmenting the “heart wall” is trivial, using thresholding. You can limit segmenting the ventricles inside the heart using “Wrap Solidify” effect (provided by SurfaceWrapSolidify extension), then splitting the ventricles using Scissors effect. Once you learned how to use the tools, the whole process should take just a couple of minutes.
Thanks very much @lassoan!
By using the Threshold effect, I can extract the entire 3D heart model or as you said the “heart wall” but I still need to practice “Wrap Solidify”.
from this video https://www.youtube.com/watch?v=IWo-QlU4J_c I understood nothing 
but I have this extension now and will try to apply it. p.s. It’s quite difficult for non-physicians to identify each organ correctly 
This is just a demo video that shows the end results. To fill a cavity you need to create a small seed segment inside the cavity you want to segment (it can be a small sphere that you create with a single click using the Paint effect), then choose the “heart wall” segment in the segment list at the top, and choose your “seed” segment as “Custom” region, then click “Apply”:
Result after clicking apply: the seed region is expanded to fill the cavity
