How show the bone of a serial dicom files!

Now I have the same serials of dicom files, How to show only bones when i rendering it using Volume rendering? Like the RadiAnt Dicom Viewer software!!!

You can get nice volume rendering of bones using VTK volume raycast mappers. See VTK volume rendering examples for details. The only part that is not covered by the examples is that you need to set up custom scalar opacity and color transfer functions to get good-looking rendering. You can find several volume rendering presets that you can start from and interactively edit in 3D Slicer:

By the way, 3D Slicer is free, open-source, VTK-based, does everything that RadiAnt can do (and lots more). So, you are in for a replacement for RadiAnt then check it out.

Yes,I’ve been able to display bones by adjusting color opacity, but I hope my program can automatically calculate gray values(or CT value) to show only bones!

Clinical CT imaging systems are properly calibrated for having voxel values in Hounsfield units, therefore you can use the same default preset for showing bones on any CT image. Bones are particularly easy to display because they have much higher density than surrounding soft tissues. You may want to offer the user to slightly adjust offset and scale of the transfer functions to fine-tune opacity and sharpness of edges.