Comparison and optimization of imaging techniques in suspected physical abuse paediatric radiography

This study compares protocols in clinical use for paediatric suspected physical abuse (SPA) radiographic imaging across four National Health Service Trusts in the UK. The patient dose delivered from a SPA skeletal survey was compared between two sites using different imaging technology. Additionally, the technique in use for the abdomen anteroposterior (AP) radiographic projection was optimized at one of the participant sites.

Retrospective data collection was performed to compare SPA protocols. Exposure details and patient dose data for SPA skeletal surveys were collected and compared. SPA skeletal surveys were performed on two anthropomorphic paediatric phantoms using two digital imaging systems. Effective dose (ED) was calculated using a dose calculator software (PCXMC v. 2.0, STUK, Helsinki, Finland) and used as a quantification of the radiation risk. For the optimization study, abdomen AP radiographs of the phantoms were acquired over a range of tube potentials (40-117 kV) for constant ED on a digital radiography (DR) system. The contrast-to-noise ratio (CNR) between "bone" and "soft tissue" in the images was measured and used as an indicator of image quality.

This study showed that there is a variation in the protocols and a range of techniques in use for SPA imaging across the four participant sites. The skeletal surveys undertaken on the newborn phantom at two sites resulted in an ED of 57 ± 3 µSv and 90 ± 4 µSv, on the DR unit and digital radiography/fluoroscopy (dRF) unit, respectively. Measurements of the abdomen AP projection achieved an improved CNR (4%) at a lower tube potential (55 kV) without increasing ED, compared with the current clinical setting (64 kV). Advances in knowledge: This study showed that an improved CNR can be achieved for newborn and 1-year-old abdomen AP radiographs using 0.1 mm copper filtration and a reduced kV (55 kV) without increasing ED.