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29 August 2008

Answer to Question #529 Submitted to "Ask the Experts"

Category: Medical and Dental Equipment/Shielding — Equipment

The following question was answered by an expert in the appropriate field:

I am simply inquiring over which, if given a choice of x-ray equipment, is better to use—a mobile x-ray machine that is capacitor discharge made in 1976 or a fixed-tube that is five years old. I need this question answered on safety for the operator and user only. Which allows for less dose to operator and user?

I would recommend the fixed-tube system. Capacitor discharge units were designed primarily for mobile operation and have several weaknesses. For example, the kilovoltage is typically lower than what is selected due to the fact that the capacitors discharge during the exposure, lowering the kilovoltage. Unless higher kVp techniques are selected, this will result in increased radiation dose to the patients. I am not aware of any firm manufacturing capacitor discharge units today. This is considered outdated technology. Furthermore, I would be concerned about equipment that is 25 years old.

Joel Gray, PhD

Answer posted on 19 December 2000. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.