These examples usually answer all the questions that facilities have about shielding evaluation requirements. However, if you are still confused if you need a shielding evaluation, please contact us so we can help review your situation.
FAQs
Who are We?
Radiation Physics Consultants is a group of experienced Medical Physicists and Radiation QC Specialists assisting you to provide the best patient imaging while improving patient and staff safety.
RPC provides radiology equipment testing, image quality review and radiation safety guidance. We assist you with meeting and exceeding quality and safety standards as required by state and federal regulations. We also help assure new equipment purchases meet all vendor promised specifications, including accreditation testing.
Though meeting regulations is important, our main philosophy is to provide patients the best diagnostic images at the lowest dose possible. We help to assure your facility uses the best imaging and safety practices that will exceed all regulations.
We just purchased a couple mobile c-arms and portable radiographic units. Since these are mobile, do we need a shielding plan?
Mobile x-ray units are often overlooked as possibly needing shielding evaluations. Portable radiographic units are rarely used in the same area repeatedly. However, if it is used in the same room on a regular basis, then it would need a shielding plan. A common scenario is a surgery department that has 1 or more mobile c-arms which are used in a couple specific surgery rooms. The continual use of the equipment in the same rooms warrant a shielding evaluation. This situation typically does not require any special shielding materials. Instead we determine how far away from each wall the c-arm must remain to assure areas beyond the wall do not go over safe levels of radiation.
We are installing a ‘low dose’ unit. Do we even need any shielding materials or shielding plan?
State laws differ on definition of ‘low dose units’ and requirements. Usually units such as mammography, intraoral and bone density are considered ‘low dose’ (or as we say lower dose). However, most states still require a shielding plan/evaluation to prove that standard building materials will properly shield (usually standard sheetrock and solid wood doors suffice). Most states do not require state inspectors to review shielding plans for low dose units, but a plan must be permanently maintained on site.
We are replacing an old radiographic room with a new radiographic room. Since it is just replacement of the same type of equipment, do we need a shielding plan?
First, do you currently have a shielding plan for the old room onsite? An actual shielding plan should include floor plans, indicate which walls/barriers have shielding materials, type/ amount of shielding materials, and calculations which prove the existing shielding materials properly reduce the scatter radiation to a safe level. Often the closest thing a facility will find to a shielding plan is a notation on a floor plan drawing saying “1/16 in. Lead.” It is not an acceptable shielding plan if the documents do not show specifics for each barrier or calculations to verify the assumed materials are enough. If you do not have an old shielding plan, a new shielding evaluation must be performed (even for room structural remodeling).
Second, is the new equipment more powerful than the old equipment (resulting in more scatter radiation)? Or will the patient work load increase from what was used for the old shielding plan? Have any of the rooms surrounding the exam room been changed to a different type of room (such as a closet is now an office)? These types of changes will result in people receiving more scatter radiation, and therefore require a new plan. Note: State inspectors have even required a new plan even though the new equipment is lower dose than the older equipment. We always recommend talking with a state inspector and getting the answer in writing to keep in your QA Manual.
Third, if there is no old shielding plan, and a new shielding evaluation is performed, you still need to determine the amount and type of shielding materials built in each wall, door, window, ceiling and floor. If the new shielding evaluation determines the North Wall needs 1/32″ Lead, you must verify there is at least 1/32″ Lead already in that wall. Otherwise that wall will need to be replaced. Usually wall outlet boxes or suspended ceiling allow you to look at the edge of the sheetrock where the lead is attached. You can measure the Lead with a ruler. Otherwise a ‘core sample’ can be drilled out of the wall to be measured. A core sample is a small circular piece of the wall that is drilled out at the floor boards, measured and re-inserted in the whole.
We are not replacing our x-ray equipment, but we are moving a wall or window or door. Does this require a shielding plan?
Yes. It would only require an evaluation of the modified barriers/walls. Typically it is just as easy to evaluate all the barriers. This verifies issues such as increased patient workload or changes in rooms types (use of adjacent rooms) has not resulted in needing more shielding than initially required when the room was originally built.
Our equipment vendor told us they always use 1/16″ Lead in all walls. He also told us this would be more than enough since we have low patient volume. Do we need anything else for a shielding evaluation?
Yes. It is common for equipment vendors to simply specify 1/16″ Lead, as this is usually more than enough for most exam rooms with moderate patient volumes. However, without analyzing and calculating the estimated amount of scatter radiation, there is no way to verify the 1/16″ Lead is enough. A shielding plan/evaluation must be permanently maintained onsite. If the building is sold, the shielding plan must stay with the building.