Diagnostic accuracy of multi-slice unenhanced whole body post-mortem computed tomography for the identification of fractures following sudden unexpected death in children below 2 years of age

Abstract

This thesis aims to test the hypothesis that introducing a protocol involving whole-body post-mortem computed tomography skeletal survey (PMCT-SS) prior to autopsy can enhance the diagnostic accuracy of fracture detection in cases of sudden unexpected death in infancy (SUDI) and childhood (SUDC) under 2 years of age. As the PhD candidate is from Saudi Arabia, the research also explores Saudi public views and preferences on post-mortem examinations for SUDI and SUDC, with the goal of informing future practice in the candidate’s home country.

Chapter 3 shows the results of a systematic review and meta-analysis on post-mortem imaging. PMCT shows low sensitivity (66%) but high specificity (92%) compared to autopsy, with broad agreement in identifying causes of death related to child abuse. Chapter 4 examines the diagnostic performance of PMCT-SS compared with radiographic skeletal survey (R-SS) in identifying inflicted fractures in 45 subjects, using autopsy as a reference standard. PMCT-SS is 12.5% more sensitive, particularly for skull, rib, clavicle, vertebra, and scapula fractures, except metaphyseal fractures. Specificities exceed 90% for both. Chapter 5 documents the timing of the appearance of radiological signs of fracture healing from PMCT-SS and R-SS and assesses their agreement to determine whether PMCT-SS could improve or replace R-SS in dating fractures. Differences in inter- reader and inter-modality agreement indicate that PMCT-SS cannot yet improve or replace R-SS in dating fractures. Chapter 6 reports on PMCT-SS image quality, finding artefacts, alignment, and coverage issues as main limitations. Chapter 7 investigates Saudi public opinion through a survey of 1,012 participants. About one third (34.4%) support autopsy, 41.9% are neutral, and 23.7% disagree, though most accept it if crime is suspected. Post-mortem imaging is widely accepted (84.7%).

The findings indicate that PMCT-SS improves fracture detection and offers higher diagnostic accuracy than R-SS, apart from metaphyseal fractures. Despite the overall improved performance of PMCT-SS, the combined use of both modalities is recommended to minimise the risk of missing metaphyseal fractures. The public survey showed broad acceptance of post-mortem examinations in Saudi Arabia, even in non- suspicious deaths, supporting the development of a national approach aligned with the most robust recommendations.