Mark,
From your description, I am a little unclear about how you want to represent the 3D image. If you are trying to build a 3D array of multiple 2D images, you could use the image to array function provided with LabVIEW to access the 2D array, and then build a single 3D array from multiple images. If you are looking to display a single image in some 3D form such as a graph, you could again access the array of the image, and use a 3D graph or Intensity graph to display it.
I hope this helps!
Best Regards,
Chris D
NI Applications Engineer