Abstract
INTRODUCTION: The Royal College of Radiologists and the Society and College of Radiographers in the United Kingdom published 'Standards for the provision of an ultrasound service', including application-specific limiting values for resolution and penetration. No measurement methods were detailed. We aimed to explore a possible theoretical basis for the standards and to develop a measurement protocol. METHODS: Since application-specific standards fail to account for probes of different frequencies used for similar applications and no evidence for the standards was provided, we developed generic standards based on theoretical considerations. In a trial implementation of the published standards, automated measurements were made on four recently purchased scanners with a total of eight probes, results being assessed against the standards. Measurements were made on 15 modern probes and used to develop our generic standards. RESULTS: Automated measurements showed less inter- and intra-observer variability than manual/visual measurements. Four new ultrasound scanners with a total of eight probes all failed to meet the published axial and lateral resolution standards; three failed to meet the penetration standard. Our generic standards were tested on 15 probes, four probes failing to meet the revised standards. CONCLUSIONS: Automated methods are essential for measurements against standards. New generic standards with a theoretical basis have been proposed. Further work is required to refine standards and methods and to determine the appropriate contributions of objective and subjective equipment selection methods.