Taking data from CT scan and printing 3D model

Support
1

Operating system: windows
Slicer version: 5.6.1
Expected behavior: setting a ROI and creating a 3d printable model
Actual behavior: images are shown in 3 of the 4 windows, but have not been able to create a ROI image in the 3D window.

I am a newbie to 3D Slicer and DICOM files. I have scan files of my chest and want to print the ROI of my heart. I know how to 3D print once I have a STL. I am not able to create the model from my data.
Thank you for your support.

2

Have you been though the training material? Get things working with the sample data and then try the same on your data.
https://www.slicer.org/wiki/Documentation/Nightly/Training#Segmentation