Safe Distance for Pan/Ceph Exposures

Recently we have had some interesting developments relating to pan and ceph installations that have fixed exposure buttons outside in a hallway. Many of these remote exposure button locations are installed prior to our arrival by electricians who may not have any concept on where they should really be located. The other issue that we have run into is site planning that was completed by architects who had no regard for how the X-Ray machine works and what safe locations and distances need to be.

There are several points to be considered when placing a remote exposure button:

  • Operator must be at least 6 feet from the patient being exposed by a panoramic X-
    ray unit.
  • Operator must be able to view the patient throughout the entire rotation.
  • Ceph exposures should be optimally oriented so that the scatter radiation (Radiation that misses the cassette) should exit the building though an exterior wall or be knocked down by some type of lead shielding.

There are several things that we can do to accomplish the above goals.

  • If the operator’s remote exposure button is closer than 6 feet, we can install a coiled exposure cord at the present button location, allowing the operator to pick it up and step further away from the machine than 6 feet.
  • Mirrors can be installed on walls to aid the operator’s visibility of the patient during exposure while still allowing for minimum safe distance.
  • If the machine can not be relocated to allow for outside orientation of the ceph exposure, it may be necessary to install extra layers of sheetrock or install some type of lead curtain or shield to knock down the scatter radiation of the ceph. There is a company, Pacific Northwest X-Ray, Inc. that specializes in many types of lead curtains and shielding materials.
  • Beyond all of this, you can hire a physicist to measure the scatter radiation from your X-ray machine to see if you have anything to be concerned about. Here is a list of a few that we are aware of:

Minneapolis Radiation
Mary Fox, M.D.
6401 France Ave S.
Edina, MN

Richard Geise, Ph.D.
18430 – 5th Ave N.
Plymouth, MN 55447

University of Minnesota
Bruce Gerbi, Ph.D.
Box 494, UMHC, Harvard
& East River Road
Minneapolis, MN 55455

St. Joseph’s Hospital
Guy Sherwood
69 West Exchange St.
St. Paul,
MN 55102