Context
Prof. Owen Arthurs gave paediatric-radiology expert evidence for the prosecution at the 2022–2023 Letby trial. Prof. Arthurs is Consultant Paediatric Radiologist at Great Ormond Street Hospital for Children and Professor of Paediatric Radiology at University College London — an internationally recognised specialist in perinatal post-mortem imaging. The Crown called him to interpret post-mortem radiological findings (post-mortem MRI and CT) for several indicted cases in the context of its air-embolism theory.
Full contemporaneous testimony is archived in the Chester Standard live-blog coverage. This page is a structured reference summary; the independent paediatric-radiology re-reading filed with the October 2025 CCRC application is a separate document.
What Prof. Arthurs testified to
- His interpretation of post-mortem imaging for the air-embolism cases against the Crown’s theory of intravascular gas administration.
- The Royal College of Radiologists framework for post-mortem-MRI and PMCT interpretation, with specific attention to the pattern recognition required for venous air embolism on imaging.
- His professional assessment of the imaging findings for specific indicted cases in which post-mortem imaging was available.
The independent post-conviction re-reading
As part of the October 2025 CCRC application, independent paediatric radiologists conducted a re-reading of the original imaging for several indicted cases. Their key findings:
- Post-mortem imaging in the indicted cases does not show the intravascular gas pattern venous air embolism would produce at the volumes and locations the prosecution’s theory required.
- The differential-diagnosis framework for non-specific imaging findings (post-mortem decompositional gas, gas from resuscitation efforts, gas from natural gastrointestinal sources) was not fully set out at trial.
- The Royal College of Radiologists’ guidance for interpreting post-mortem imaging in neonates has standards that independent reviewers apply against the trial record.
- Several paediatric-radiology specialists have publicly disputed specific interpretations of the original trial imaging in the peer-reviewed and professional literature since conviction.
Read alongside
Prof. Owen Arthurs — biography, Evidence: radiographs, Evidence: post-mortem findings, Evidence: air embolism, Evidence: forensic-pathology standard, Transcript: independent paediatric-pathology re-reading.