You can import your DICOM image to 3D Slicer (www.slicer.org) and segment the airways using Segment Editor module. Segmentation can be visualized in 3D and exported to 3D model files.

There's also ITKSNAP an opensource project which uses 3D snakes to implement segmentation on medical data.

http://www.itksnap.org/

1.- Choose File > Open, select a DICOM file, and click Open.

2.- Select the frames you want to convert to a 3D volume. Shift-click to select contiguous frames. To select noncontiguous frames, Ctrl-click (Windows) or  Command-click (Mac OS). Click Select All to select all frames.

3.- In Frame Import Options, select Import as volume, then click Open.

Photoshop creates a 3D volume of the DICOM frames and places it on a 3D layer in the Layers panel. You can use Photoshop’s 3D position tools to view the 3D volume from any angle, or change render settings to better visualize data.

The original DICOM file is preserved as a Diffuse texture layer associated with the 3D volume layer. For information on 3D textures,

Double-click the texture layer to open the DICOM file as a Smart Object in its own document window. The DICOM frames appear as separate layers in the Layers panel.

Any changes you make to individual layers are applied to the 3D volume when you close and save the Smart Object.

To save the 3D volume, you can export the 3D layer or save the file in PSD format.

Adobe Photoshop is a very good tool, but not for visualization, segmentation, registration, and analysis of 3D/4D medical images. Use 3D Slicer, ITKSnap, and others that are developed specifically for medical image computing (they are also free and open-source).

You can also use our software called Checkpoint. This will load the CT scan, give you basic 3D visualization, and also allow you to extract surfaces. The surface can be of the sinus cavities as you have shown above.

https://www.stratovan.com/products/checkpoint