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U.S. Department of Health and Human Services

Radiation-Emitting Products

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Must the compression paddle be placed in the x-ray beam during half value layer (HVL) measurements?

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If the HVL measurement is being used to calculate patient dose, the compression paddle must be placed in the x-ray beam during the measurement. If the HVL measurement is being used for purposes other than patient dose, the position of the paddle is not specifically stated in the regulations. However, FDA recommends inclusion of the compression paddle in the x-ray beam because most manufacturers have designed their equipment to be tested in this configuration.

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