X-ray Machine (Ionizing radiation producing machines) Safety

The University registration(s) were issued by the Massachusetts Department of Public Health Radiation Control Program for use in research, dentistry and veterinary diagnostic imaging.

X-ray radiation sources are divided into two categories; those machines intended to produce x-ray radiation and those machines that are not intended to produce radiation, but emit x-ray radiation due to the inherent design of the system.

Three areas that use x-ray machines at Tufts University:

  1. Veterinary Radiological Diagnostic Imaging & Therapy (Grafton)
  2. Research (Boston, Medford & Grafton)
  3. School of Dental Medicine

For the purpose of radiation protection, several exposure groups as listed below have been established to monitor radiation dose and ensure As Low as Reasonably Achievable (ALARA) conditions.  The external radiation source dosimetry program is designed to monitor radiation exposure to areas or individuals as generated by radiation producing machines.  Assignment is based upon the likelihood for a workers exposure to approach a fraction of the regulatory limit established by the TU Radiation Safety Committee.  Dosimeters are supplied and processed by an accredited outside vendor.  Radiation Safety personnel administers the dosimetry program on all campus locations as a service.  Instructions for the appropriate location and use of each dosimeter assigned is detailed in RSP-063.

  1. Researchers: using any device which utilizes x-ray for the purpose of examining microstructure of materials. This includes all types of x-ray diffraction and spectrographic equipment.
    1. X-ray diffraction (XRD)
    2. X-ray fluorescence (XRF)
    3. Other x-ray analysis techniques
  1. Veterinary Radiological Diagnostic Imaging & Therapy (Grafton): personnel using different types of imaging equipment specific to the medical modality, each of which uses different technology or techniques.
    1. Radiography
    2. Fluoroscopy
    3. Computed Tomography
    4. Accelerator
  1. School of Dental Medicine: personnel using x-ray machines for human use diagnostic purposes and to aid in teaching students.
  1. Visitors: All students, operators-in-training and personnel not experienced in the use of x-ray equipment must work only under the direct supervision of a qualified operator and as approved by the Principal Investigator.

Types of machines that emit radiation vary depending on application and use.  Provided below are examples of machines that emit radiation in research or medical application.

Common x-ray radiation producing machines or systems:

  • Radiation Producing Machines:
    • Cone Beam Computed Tomography (CBCT) in dental application
    • Computed Tomography (CT) in veterinary application
    • Radiograph machines, intra oral, cephalometric and panoramic machines
    • Analytical: X-ray Diffraction (XRD), or fluorescence analysis (XRF)
    • Analytical: electron microscope
  • Common household items that emit x-ray radiation: vacuum tubes used in old radios, televisions, and other antique electronic equipment

Radiation producing machines potentially can cause injury and should be used by trained personnel only.  Training is provided by EHS and documented prior to handling any radiation producing machine.  X-ray machines used at Tufts University for research, diagnostic purposes in dentistry, or veterinary medicine are required to be registered with the RSO by using form RSP-072: “Radiation Producing Machines Permit Application”.

Safety Considerations:

  • All individuals entering work environments that employ x-ray machines need training.
  • Postings that alert Tufts University personnel and others of hazards should be accurate and conform to EHS standards (postings are provided by EHS).
  • The x-ray room must be used for only one x-ray procedure at a time.
  • Controlled access (i.e. locks, interlock circuit, etc.) to rooms using x-ray machines is required.
  • Operators should know what the dose rates are at various stages in the operation to ensure that maximum effort is directed at reducing the time of exposure during higher dose rate procedures (i.e. consider the difficulties when handling large animals during scintigraphy or other procedures that involve occupational exposure).
  • Consider additional staff trained in animal control to reduce the time for radiographic procedures.
  • Administrative Managers should coordinate diagnostic schedules with Operators to ensure qualified staff are available beforehand and with the ALARA concept in mind.
  • Operators should maintain a fault log on critical equipment so that managers can effectively identify equipment commonly malfunctioning that potentially results in longer radiation exposures to personnel.
  • Personnel will continue to handle animals directly during imaging unless improved remote handling tools or devices are specifically designed to better manage animals.
  • Shielding should be employed to accommodate operations where time is optimized and distancing is not feasible and ALARA conditions are not achieved.
  • The regulatory required minimum thickness (.25 mm) lead aprons are much lighter, and should be considered to relieve physical burden on personnel exposed to low levels of scatter radiation.
  • There should be further consideration to wearing lighter (i.e. weighing ¼ to what is available) aprons that provide optimum shielding for those handling animals during Imaging.
  • Be familiar with safety procedures as it applies to each x-ray machine.
  • Direct access to the useful beam or diffracted beam should be avoided.
  • Request of EHS to conduct a radiation survey when changing the work environment configuration, shielding design or procedures that potentially affect radiation exposure conditions.
  • X-ray machines that are energized and ready to produce radiation must be supervised.

Please refer to Tufts University Radiation Safety Committee Policies and Procedures Manual for further information regarding the Radiation Safety Program, the Radiation Safety Committee or controls employed to safely use x-ray machines at Tufts University.