I would recommend to try AI segmentation extensions that have heart segmentation models, such as TotalSegmentator and MONAIAuto3DSeg. You can also try NNInteractive interactive AI segmentation tool.
The totalsegmentator extension has a high-res cardiac chambers segmentation option (license required). If it’s for academic use, I believe you can get the license quite easily and in my experience it has worked fairly well.
Thank you so much for your feedback!
I tried that, but my input data was not CTA, and thus maybe the difference was not much.
I would greatly appreciate if you could share an image of a result, if you got realistic one.
Thanks