The two softwares for annotating medical (Dicom images) are:
1. Microdicom: https://www.microdicom.com/
2. GIMP Download: https://www.gimp.org/downloads/
3. Examples of dicom images to download: https://www.kaggle.com/abhishek/siim-...
Other Softwares to view and segment in 3D
Slicer3D viewer and segmentation 3D tollkit: • 3D Slicer Tutorial - Segmentation Wizard