Diagnostic image quality of mobile neonatal chest X-rays and the radiation exposure incurred.

A study was undertaken to identify the variation of entrance skin doses (ESDs) in mobile neonatal chest radiography with regard to the European Commission (EC) reference dose and to examine potential relationships with image quality and radiographic techniques. Five sites from the former North West Thames region participated. All mobile neonatal radiographic techniques were surveyed. Dose-area product per examination was directly measured and the ESD calculated. Image quality criteria were developed from those published by the EC. Image quality was graded by two independent observers. Over the five sites, 144 examinations were recorded. Calculated ESDs ranged up to 160 microGy, with an appreciable variation not only between sites but also within sites. A clear relationship between actual rather than nominal speed and dose over all sites was demonstrated (r = -0.95, p = 0.013). No correlation between image quality and dose was noted (r = -0.044, p = 0.665). Neonatal imaging systems at participating sites, within the North Thames region, comply with EC guidelines on patient dose and image quality for mobile chest X-rays. Significant variation in ESDs was encountered between sites with no discernible relationship with image quality or the employed radiographic techniques as described by the EC. The strong inverse relationship between ESDs and actual rather than nominal speed suggests a neglected aspect of radiation protection.