What are the room shielding requirements for portable C-Arm (Computed Radiography Arm) fluoroscopy?

Room Shielding Requirements for Portable C-Arm Fluoroscopy

Portable C-Arm fluoroscopy does not require permanent room shielding, but instead relies on proper use of personal protective equipment, mobile shields, and maintaining appropriate distance from the radiation source to ensure safety. 1

Personal Protective Equipment Requirements

Essential Protective Gear

• Lead or lead-equivalent aprons (0.25-0.5 mm thickness) that:

  • Cover the entire torso
  • Extend to mid-thigh
  • Wrap around the body
  • Absorb 95% of 70 kVp X-rays and 85% of 100 kVp X-rays 1

• Thyroid shields are critical as they:

  • Protect the thyroid and cervical bone marrow
  • Decrease effective radiation dose by approximately 50% 1

• Leaded eyeglasses with side shields for personnel working close to the X-ray source 1

Mobile Shielding Requirements

Instead of permanent room shielding, portable C-Arms require:

• Ceiling-mounted lead acrylic shields positioned between the patient's thorax and operator's upper body

  • Must be repositioned when C-arm position changes
  • Can reduce operator exposure to thorax and head by about 90% 2

• Table-side drapes with hinges to maintain shielding when X-ray tube position changes 2

• Under-table shielding (0.5 mm lead-equivalent) to intercept backscatter from patient and table 1

• Mobile "door-type" shields for additional protection during longer procedures 2

Distance and Positioning Considerations

• Inverse square law is critical: doubling distance from 2 feet to 4 feet reduces exposure to one-fourth the original level 2
• Personnel not directly involved should remain at least 8 feet from the patient 2
• Position the image detector as close to the patient as possible 2
• Maintain maximum possible distance between operator and X-ray source 1

Operational Safety Measures

• Use collimation to minimize the exposed field size 2
• Select lowest-dose imaging modality appropriate for the procedure 2
• Use the slowest fluoroscopy pulse rates that yield appropriate quality images 2
• Limit fluoroscopy to actual catheter manipulations requiring visualization 2
• Utilize "last image hold" feature to avoid additional exposures 2

Maintenance and Inspection

• Lead aprons and thyroid shields must be fluoroscoped at least annually to check for cracks and holes 1
• Damaged protective equipment should be replaced immediately 1
• Older aprons have higher risk of damage - a study found 42.3% of aprons used since 2005 were damaged 3

Monitoring Requirements

• Personnel should wear two radiation badges:
  • One under lead apron at waist level
  • One outside lead shields at collar level 2
• Pregnant workers should wear an additional abdominal badge under the apron 1
• Regularly review personal exposure and adjust techniques if exposure exceeds recommended levels 2

Training Requirements

• All personnel should participate in annual radiation safety training sessions 2
• New personnel must be adequately trained before working with C-arm fluoroscopy 2
• Establish equipment and practice standards to reduce variations in adherence to recommendations 2

While permanent room shielding is not required for portable C-arm fluoroscopy, the combination of personal protective equipment, mobile shields, and proper distance management provides effective radiation protection when properly implemented and maintained.