Neonatal chest radiography : influence of standard clinical protocols and radiographic equipment on pathology visibility and radiation dose using a neonatal chest phantom

Introduction: Little is known about the variations in pathology visibility (PV) and their corresponding radiation dose values for neonatal chest radiography, between and within hospitals. Large variations in PV could influence the diagnostic outcome and the variations in radiation dose could affect the risk to patients. The aim of this study is to compare the PV and radiation dose for standard neonatal chest radiography protocols among a series of public hospitals. Methods: A Gammex 610 neonatal chest phantom was used to simulate the chest region of neonates. Radiographic acquisitions were conducted on 17 X-ray machines located in eight hospitals, utilising their current neonatal chest radiography protocols. Six qualified radiographers assessed PV visually using a relative visual grading analysis (VGA). Signal to noise ratios (SNR) and contrast to noise ratios (CNR) were measured as a measure of image quality (IQ). Incident air kerma (IAK) was measured using a solid-state dosimeter. Results: PV and radiation dose varied substantially between and within hospitals. For PV, the mean (range) VGA scores, between and within the hospitals, were 2.69 (2.00 to 3.50) and 2.73 (2.33 to 3.33), respectively. For IAK, the mean (range), between and within the hospitals, were 24.45 (8.11 to 49.94) µGy and 34.86 (22.26 to 49.94) µGy, respectively. Conclusion: Between and within participating hospitals there was wide variation in the visibility of simulated pathology and radiation dose (IAK). Implications for practice: X-ray units with lower PV and higher doses require optimisation of their standard clinical protocols. Institutions which can offer acceptable levels of PV but with lower radiation doses should help facilitate national optimisation processes