Fluoroscopy Room Shielding Requirements:What You Need to Know

A fluoroscopy room uses X-rays to make moving images in real time. Because the X-ray beam may stay on much longer than it does during a normal X-ray exam, room shielding needs to be planned carefully. But fluoroscopy shielding is different from regular X-ray room shielding.

Why is fluoroscopy different?

During normal radiography, the X-ray beam may point toward a wall, floor, table, or wall stand. Fluoroscopy equipment works differently. The main X-ray beam is normally captured by the image receptor or detector on the other side of the patient.

NCRP Report No. 147 explains that the image receptor acts as a primary barrier for the fluoroscopy beam. Because of this, a room used only for fluoroscopy may mainly need protection from secondary radiation, such as radiation scattered from the patient.

That does not mean a fluoroscopy room does not need shielding. It means the shielding calculation is different.

What is scatter radiation?

When X-rays hit a patient, some of the radiation changes direction. This is called scatter radiation. Scatter can travel toward the walls, doors, control area, and people in or near the room. The amount of scatter depends on how much the fluoroscopy system is used and the techniques used during procedures. The shielding around the room helps reduce this radiation.

How much shielding does a fluoroscopy room need?

There is no standard amount. The design depends on the room and how the equipment will be used. Important factors include:

• Type of fluoroscopy system
• Number of procedures
• Length and type of procedures
• Equipment position
• Patient location
• Distance to surrounding areas
• Occupancy of nearby rooms
• Existing wall and floor construction

A busy fluoroscopy room may need more shielding than a room used only a few times each week.

Does a fluoroscopy room need primary barriers?

Sometimes. NCRP 147 explains that a room containing only a fluoroscopy system may only need secondary barriers because the image receptor normally intercepts the primary beam.

However, the report also points out an important design choice. A physicist may decide to provide primary-barrier shielding so the room can be used differently in the future without major construction changes. This can be useful when a hospital expects equipment or room use to change later.

What if the room also takes regular X-rays?

Many fluoroscopy systems can also perform radiographic exposures. When that happens, the room should not be designed using fluoroscopy alone. NCRP 147 recommends considering the combined workload of both parts of the system. In simple terms, the shielding calculation needs to include all the ways the X-ray equipment will be used.

What about interventional fluoroscopy?

Interventional rooms deserve special attention. Examples include:

• Cardiac catheterization labs
• Angiography rooms
• Neurointerventional rooms

These rooms often perform longer procedures and may use fluoroscopy, cine imaging, and digital radiography. NCRP 147 notes that workloads in interventional rooms are generally high. It also notes that some rooms have more than one X-ray tube, and each tube needs to be included in the shielding evaluation.

For that reason, I would treat cath labs and interventional rooms as their own shielding category rather than assuming they are the same as a normal fluoroscopy room.

Do the walls need lead?

Maybe. The required shielding may be provided by lead, gypsum wallboard, concrete, other approved building materials, or a combination of materials. The physicist calculates how much radiation the barrier needs to stop. Then the design can determine the best construction method. Adding lead to every wall without doing a calculation can waste money.

What about doors and windows?

Doors and windows should be included in the shielding design. A door may need a specific lead equivalence. The control-room window may need lead glass or lead acrylic. The frames and joints around these barriers also need to maintain the required protection. A good shielding report should make these requirements easy for the architect and contractor to understand.

Should the floor and ceiling be checked?

Yes. People may work above or below the fluoroscopy room. The floor and ceiling should therefore be part of the shielding review. Existing concrete may provide enough shielding in some cases. The design should verify that before construction begins.

What shielding goals does NCRP 147 use?

NCRP 147 recommends a weekly shielding design goal of 0.1 mGy for controlled areas and 0.02 mGy for uncontrolled areas. The physicist also considers how often nearby spaces are occupied. For example, a full-time office is different from a storage room that is only entered for short periods.

Plan fluoroscopy shielding early

Fluoroscopy equipment is expensive. Fixing shielding after the room is finished can also be expensive. The shielding design should be completed while the project is still in the planning stage. That gives the architect, equipment vendor, contractor, and physicist time to make sure the equipment and room design work together.

Need a fluoroscopy shielding design? Heartland Physics provides shielding calculations for diagnostic and fluoroscopic X-ray facilities. Send us the floor plan, equipment information, expected workload, and project location to get started.