Which of the following radiologic procedures are considered nonessential?

The X-Ray Safety Manual contains procedural guidelines and information for prudent work practices while using any x-ray producing device (XPD) at USC. The manual is made available to every area authorized to use XPDs and any area where XPDs are present.

How do I:

• Get approval to purchase an XPD?
• Register, transfer, or dispose of an XPD?
  • Email [email protected] to begin the process. XPDs must be registered within thirty (30) days of the acquisition date.
  • What needs to be registered?
• Obtain a dosimeter badge and ring?

Safety Tips and Guidelines

Additional safety tips and guidelines are available for the following x-ray equipment and techniques.

Resources

• X-Ray Safety Manual
• X-Ray Safety and Emergency Procedures – fillable form

Cabinet X-Ray

A cabinet X-ray device is an entirely shielded system that stops most radiation from leaving the enclosure. Examples of cabinet X-ray systems at USC include X-ray irradiators and digital X-ray cabinets.

The enclosure is typically made of lead and is designed to attenuate radiation to levels below 0.5 mR/hr at any point 5 centimeters from any surface of the device. Lead PPE and personal dosimetry are not required when using a cabinet X-ray device because radiation remains at background levels during operation.

Device Users are advised to continue following ALARA (as low as reasonably achievable) principles when using the device:

• Time: Minimize your time around the energized device.
• Distance: Maximize your distance away from the device. Do not stand too close to the machine during operation.
• Shielding: Do not tamper with the shielding built into the device.

Cabinet X-ray devices have safety features that prevent X-ray production when the X-ray source is accessible and warn the user when X-rays are being produced. Examples of interlocks include:

• A physical interlock in the door that breaks the circuit controlling X-ray production when the door is opened
• An electrical sensor that stops X-ray production when the door is opened
• Lights indicating when X-rays are being produced or when the shutter is open
• An alarm indicating that the shutter is open

It is essential to maintain the integrity of the shielding and safety devices by following these safe practices:

• Do not bypass any safety interlocks.
• Do not tamper or alter the device shielding.
• Do not attempt to repair the device. Contact the manufacturer.
• Use the device only for its authorized use.
• Complete preventative maintenance, as recommended by the device manufacturer.

The Radiation Safety Office will complete a leakage survey upon installation or any major repair and constantly monitors all rooms that house a cabinet X-ray device for leakage radiation with area dosimeters. All device malfunctions or suspected incidents must be reported to the Radiation Safety Officer immediately.

Reference
Title 17 California Code of Regulations Subchapter 4. Radiation

Electron Microscope

To ensure exposures are As Low As Resonably Achievable (ALARA), EM users will conduct the following:

• Ensure that shielding, safety interlocks, and warning lights are maintained and operable.
• Turn off EMs when not in use.
• Reduce time around energized EMs.
• Maximize distance away from energized EMs. Keep hands/arms off the energized EM unless working with it.

Additionally, EM users must:

• Know safe operating and emergency procedures.
• Complete device-specific training with the Supervisor of the EM.
• Never alter the original design or shielding of the EM without written approval from the Radiation Safety Officer (RSO).
• Log user name and date of EM usage.
• Notify the EM Owner/Supervisor and RSO of any radiation incidents or unsafe practices.

EM Owners/Supervisors must:

• Document all training given to EM Users.
• Notify the RSO of the installation, relocation, disposal, or
  transfer of the EM.
• Provide written operating and emergency procedures to EM Users.
• Secure the EM from unauthorized users.
• Email [email protected] to begin registration of the EM. NOTE: All EMs (e.g., transmission, scanning, reflection, scanning transmission, low voltage) must be registered with the California Department of Public Health (CDPH) and USC Radiation Safety within thirty (30) days of acquisition.

Download the Electron Microscope Safety Guide Sheet to review and record user compliance.

Handheld Dental X-ray Unit

Individuals who operate dental X-ray units must be aware of the risks of radiation and follow safe work practices to keep patient exposure and their own exposure As Low As Reasonably Achievable (ALARA).

Operator Safety
Handheld X-ray units have a backscatter shield installed to protect the operator from backscattered radiation. The location of the shield and positioning of the patient is essential to maximize the shielded area (green) from backscatter radiation (red) – see illustrations. The operator should remain in the shielded area during the exposure.

Patient Safety

• • Exposure time increases when the imaging angle varies from 90 degrees (or perpendicular) to the film or sensor. Adjust the patient’s head as needed to maintain proper perpendicular alignment.
  • Always use the lowest exposure settings possible that provide an image of diagnostic quality.
  • Use lead protective aprons and thyroid collar whenever possible. The thyroid gland is especially radiosensitive in children.
  • Limit the number of images to a minimum necessary to obtain essential diagnostic information. Carefully plan each exposure to prevent the need for repetition.

Handheld X-ray Fluorescence Analyzer

These guidelines do not apply to handheld dental units. For more information, see Handheld Dental X-ray Unit above.

X-ray fluorescence is the emission of characteristic X-rays from excited atoms in a material that was bombarded with X-rays. X-ray Fluorescence Analyzers (XFAs) use this phenomenon for non-destructive elemental and chemical analysis and are typically used for research in geochemistry and archaeology.

Primary Beam Risks
When operated at its maximum voltage setting, a typical XFA can deliver a dose of more than 4,000 rads in one hour. Acute effects of radiation exposure to the skin can be found in Table 1. The operator must keep all body parts as far away from the nose of the device (where the beam shutter is located) as possible.

Scatter Radiation Risks
Some radiation is scattered back toward the operator and is dependent on the density of the sample material. Scatter radiation is monitored by Radiation Safety by placing a dosimeter on the device at the typical location of the operator’s hand. Although scatter radiation is less of a hazard than the primary beam, the operator must keep his/her hands and eyes away from the nose of the device at all times.

Safety Features

• An infrared sensor at the nose of the device prevents the unit from emitting X-rays in the absence of a sample in front of it. Note: This does not stop the device from emitting X-rays if a body part is in front of the device.
• Warning lights illuminate when X-rays are being generated.

Proper Setup

• 
  Do not hold the sample to the window of the device by hand. Instead, bring the window of the device to the sample. If the object cannot stand on its own, place the sample down on a surface, or use a benchtop stand (see Figure 1).
• Be aware of the direction of the direction that the X-rays travel. XFAs typically emit X-rays at an upward angle.
• The device should always be pointed away from any other people or the general public. Anyone not operating the device should stay at least 3 feet away.
  • When working in a lab, designate an area for sample analysis. The XFA should point toward an unoccupied area of at least a 3 foot radius. Do not assume that a wall or partition provides safe shielding for people on the other side. If using the device near a wall or barrier, ensure no one is on the other side.
  • When working in the field, clear the area before beginning analysis and verbally notify anyone working around you. Use indicators (e.g. cones, barriers) to prevent others from entering the area.
• Use a benchtop stand if low-density samples are measured frequently. More radiation is backscattered and less radiation is attenuated when analyzing low density samples (e.g. plastic, wood, soil), which can cause a higher dose to the operator.

Table 1. Responses of the Skin to Radiation

References
CDC – Cutaneous Radiation Injury (CRI): A Fact Sheet for Clinicians
Bruker AXS Handheld, Inc. X-ray Radiation Safety Operator Training Manual
Centers for Disease Control and Prevention (CDC)

Veterinary Research Fluoroscopy

Fluoroscopy is a method of continuous X-ray imaging that allows for real-time monitoring of a procedure. The primary fluoroscopy beam produces radiation at a rate of 2000-5000 mR/minute and produces high levels of scatter radiation when the animal on the table is exposed to it.

Which of the following radiographic procedures are considered unnecessary quizlet?

Which of the following examinations are considered to be unnecessary radiologic procedure?

Which of the following are some of the factors that should be considered when technical exposure factors are to be selected?

Which specialty uses a non ionizing form of radiation quizlet?