Commentary: ‘Not all hand-held X-ray systems are created equal’

Dental Tribune
Mar 8, 2012

by Dr Joel Gray, USA

Dr. Joel Gray
As a recent article on this website points out, there are some safety issues with hand-held X-ray units made in China and Korea, as well as elsewhere outside the USA. There are two sources of radiation from an X-ray system—leakage radiation from the X-ray tube and scattered radiation from the patient. The leakage radiation is minimised by placing highly absorbing material, such as lead, around the X-ray tube. The major issue with the hand-held X-ray units is the scattered radiation, that is X-rays that are scattered from the patient towards the operator. In fact, about 20 to 30% of the X-rays are scattered from the patient towards the person holding the device.

The X-ray units from outside the USA, which are under FDA scrutiny, do not provide any protection from X-rays scattered from the patient. These systems look like a large camera that you hold with both hands. There is no shielding provided by these hand-held systems, that is the user’s hands are exposed to all of the X-rays scattered from the patient. Consequently, the user’s hands are going to receive a radiation dose that will probably exceed the radiation-protection limits for skin and extremities. Therefore, these units should not be hand-held.

We evaluated one hand-held X-ray unit manufactured in the USA (Nomad, Aribex Inc.) and compared staff doses with those for the same staff using conventional wall-mounted systems prior to acquiring the hand-held systems (Gray et al. 2012). This hand-held system uses a proprietary shielding material around the X-ray tube, resulting in leakage radiation levels that are virtually immeasurable. In addition, it has an integral leaded-acrylic shield that protects the user from radiation scattered from the patient.

The results of our study indicated that the users of the hand-held X-ray system received lower radiation doses than they did when they were using conventional wall-mounted systems.

Buyers should be beware that not all hand-held X-ray systems are created equal and not all of those being sold on the web have been reviewed by the FDA. Hand-held X-ray units should have sufficient shielding to minimize leakage radiation from the X-ray tube and an integral shield to protect from radiation scattered from the patient.

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