Entrance Skin Exposures
The desired state for the use of radiation in chiropractic offices is to obtain necessary diagnostic information with minimal exposure to the patient, office personnel and the general public.
The Utah Division of Waste Management and Radiation Control has determined that patient exposure levels for radiographs throughout the state can vary tremendously from office to office. Division personnel have measured entrance skin exposures (ESE’s) from as low as 48 milliroentgen (mR) to as high as 1500 mR for chiropractic AP lumbar spine (AP L-Spine) radiographs. A measurement of patient (ESE’s) provides chiropractors with knowledge of their patient exposure levels and provides data which may be compared with national or state data which has been collected from their peers.
There is no regulated standard for the amount of radiation exposure a patient should receive for a specific radiographic examination. The physician must use professional judgment to evaluate the need for the radiographic examination by determining that there will be sufficient benefit to the exposed individual to offset the risks from the radiation exposure. In evaluating the data, it was determined that the average ESE for an AP L-Spine in Utah was 414 mR and the third quartile for AP L-Spine ESE’s in Utah was 522.5 mR. The third quartile indicates the ESE level which 75% of the surveyed facilities fall below. If 75% of the facilities can obtain diagnostic quality radiographs at levels below 522.5 mR, perhaps, the remaining 25% of the facilities surveyed can lower their ESE’s to attain exposure levels of 522.5 mR or below. It is the goal of the Division of Waste Management and Radiation Control to aide the chiropractic community of Utah in reducing unnecessary radiation exposure to their patients.
The following factors are the most prevalent causes for higher or lower ESE’s, and it may be any combination of these factors which can cause an increase or decrease in the measured ESE’s in a facility.
- the use of lower vs. higher kVps
- the speed of the screen/film combination used
- maintenance of the processor and x-ray unit
- film developing techniques
- clinical preference for light vs. dark films
Attached are two references, “Lowering Your ESE’s” and “A Guide for Reducing Patient Exposure” to aid you in evaluating your entire x-ray system in order to obtain good quality radiographs while adhering to the radiation exposure philosophy of “ALARA” (As Low As Reasonably Acceptable).
If you have any questions please contact a DWMRC at 536-0200.