After completing her radiology training in London, Australia, Sheffield and Nottingham, Dr Halliday was appointed as a Consultant Paediatric Radiologist at Nottingham University Hospital in 1998. She has a special interest in the imaging of suspected physical abuse and provides expert opinions for cases throughout the UK. She was Chair of the British Society of Paediatric Radiology from 2010-2016 and chaired the working group for the updated guidance for imaging in cases of suspected physical abuse in children.
In September 2017, Dr Halliday was appointed National Clinical Lead for the Getting It Right First Time (GIRFT) programme for Radiology, and the Radiology GIRFT report was published in July 2020. Dr Halliday took over as Clinical Director for Radiology at Nottingham University Hospitals in January 2021.
Dr Halliday's tenure as RCR President is 2022-2025.