People frequently ask us what, if any, requirements have been set for X-ray shielding in rooms where C-arms are in use. Unfortunately, there is no straightforward answer to the question.
Regulations for shielding during C-arm use vary across a number of factors, including site location, location of the C-arm within the site, and the type of usage the C-arm will see. Some states don't require any shielding at all, but have other requirements that must be met. Take Texas, for instance: a C-arm doesn't need to be shielded, but its dose must be monitored for a year after installation. Other states, like Ohio, require a physicist to visit your site and advise specific shielding measures for your individual building.
Because there are no across-the-board regulations for C-arm shielding, we put together a few "rule of thumb" recommendations for new C-arm owners in the example below and the short video that follows.
Shielding Plan Example: Illinois
The following example explains what one of our partner engineers does when installing C-arms in Illinois. The measures he takes won't lead to extensive shielding in all states, but they do demonstrate some of the finer points that go into the process of planning out your C-arm usage area.
What I do... is send a picture of the floor plan to my contact at Illinois’ radiation control program. He looks at the floor plan and lets me know if any shielding is required.
But the floor plan needs to be detailed. It needs to have measurements with a description of what adjacent rooms are used for... [also] the type of walls. Are they standard 2x4 walls with 1/2 inch or 5/8 inch drywall on each side? Are any exterior walls brick or cement block? Also, is it a ground level room or are there floors above and below the procedure room? If so, what is the type of construction?
Lastly, they want to know the number of anticipated procedures per day using the C-arm... if there is an office next to the procedure room but the C-arm is only being used, let’s say, twice a day the shielding required between rooms will be different than if the C-arm is being used all day, several days a week.
While regulations might look different in your area than they do in this example, it does help demonstrate two important things:
- Contact your state radiation authority as early in your C-arm project as you can.
- Have as much detail as possible on your room construction, layout, and usage level on hand.
And while we're on the subject of C-arm shielding tips that are almost always applicable, take a look at this video for two more big ones.