> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spine.altician.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Virtual C-arm

> Simulate a fluoroscopy-style X-ray projection of the loaded volume

## What Is the Virtual C-arm?

The Virtual C-arm generates a simulated X-ray projection of the loaded volume, similar to the fluoroscopy images produced by a real C-arm device in the operating room. This gives you a familiar radiographic perspective alongside the standard 3D view.

<img src="https://mintlify.s3.us-west-1.amazonaws.com/altician/images/c-arm-view.png" alt="Virtual C-arm projection view" />

## Opening the C-arm View

Click the **C-arm** button in the toolbar to open the C-arm panel. The simulated projection renders automatically based on the current volume.

## Zoom and Pan

| Action        | Control                      |
| ------------- | ---------------------------- |
| Zoom in / out | Scroll wheel                 |
| Pan the view  | Click and drag               |
| Reset view    | Double-click the C-arm panel |

## Pointer and Arrow Overlay

Pointers and arrows placed in the main 3D view are overlaid on the C-arm projection in their correct anatomical positions. This allows you to see how placed markers relate to the projected anatomy — the same way hardware appears on real fluoroscopy.

* **Pointers** appear as their chosen icon at the projected location.
* **Arrows** appear as projected lines with direction indicators.

Toggling visibility in the right panel affects both the 3D view and the C-arm overlay simultaneously.

## Adjusting the Projection Angle

Use the **angle controls** in the C-arm panel to rotate the projection:

| Control                     | Effect                              |
| --------------------------- | ----------------------------------- |
| AP (Anteroposterior) slider | Tilt the projection front-to-back   |
| Lateral slider              | Rotate the projection left-to-right |
| Reset button                | Return to default AP view           |

Changing the angle re-renders the projection in real time.

<Note>
  The Virtual C-arm works with both MRI and CT volumes. CT volumes typically produce sharper bone detail in the projection due to their higher inherent bone contrast.
</Note>

<Warning>
  The Virtual C-arm is a simulated projection for reference purposes only. It is not equivalent to intraoperative fluoroscopy and should not be used as a substitute for real imaging equipment.
</Warning>