Digital skeletal radiography - Reduction of absorbed dose by adaptation ofexposure factors and image processing

Purpose: The possibility to reduce the absorbed dose to the patient by incr ease of tube potential while maintaining the same exposure to the image pla te and sufficient image quality in skeletal radiography has been investigat ed. Material and Methods: Image processing parameters were adjusted to account for an increase in tube potential by 20 kV. Revision of image processing pa rameters was based on measurements with phantoms constructed to simulate th e histogram shape recorded for clinical images. Image quality was evaluated both using image quality criteria and visual grading analysis. Energy impa rted was calculated from measurement of the kerma-area-product. Results and Conclusion: Energy imparted was reduced by 20 30% using the mod ified technique with increased kV All images were considered of accurate qu ality for diagnosis and the difference in image quality score was marginal. There was, however, a significant shift towards lower grades for the "high kV" technique using visual grading analysis.