Rotating and Free Mode

"Free" means not constrained to an orthogonal view; in free mode the slice can be rotated to any angle. You can drag the image while in free mode; however, you must be in free mode to rotate the image; in fact, the Volume Browser places you in free mode when you select the Rotate button.


  • Note that you can switch between dragging and rotating by clicking the middle mouse button.

To rotate the image, select the Rotate button from the Volume Browser window (the yellow menu button in the example below). The Free button is then also activated (the green menu button):

  • Click the left mouse button and drag the mouse vertically to rotate about your current x-axis.
  • Click the left mouse button and drag the mouse horizontally to rotate about your current y-axis.
  • Click the right mouse button and drag the mouse to rotate about your current z-axis (about the green cross).

There is a small delay between starting rotation with the mouse and the display rotating on the screen, intended to help you rotate about a single axis when you can't move the mouse exactly the distance you want.

Using Tick Marks

The tick marks provide a guide for your rotation angle.

Optic Nerve Example

As an instance of why arbitrary rotation is important, the optic nerve cannot be completely seen in the coronal, transverse, or sagittal views. However, if you rotate a transverse view a few degrees you'll be able to see the optic nerve completely:

A transverse view of
the optic nerve.

A rotated view so the
entire optic nerve appears.