The Use of Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Post-mortem Paediatric Hearts

• Feasible workflow for diffusion tensor MRI in paediatric post-mortem hearts • Ventricular polymer filling improves myocardial structural analysis • Diffusion tensor MRI shows potential for investigating paediatric cardiac death Identification of the cause of sudden cardiac death in deceased with structurally normal hearts is a long-standing challenge in forensic medicine. Current forensic methods in conventional autopsy, including newly introduced imaging techniques, fail to identify certain pathologies behind sudden cardiac death, especially in the young. We propose that diffusion tensor magnetic resonance imaging could be used to identify currently unidentifiable pathologies. There are, however, certain technical difficulties that prevent implementation as part of a standardised autopsy workflow. This technical note aims to illustrate a feasible workflow using diffusion tensor imaging as an adjunct to the conventional autopsy. Two paediatric hearts were imaged for 1 hour and 40 minutes using a 9.4T Agilent preclinical MRI system. A standard diffusion weighted 2D multi-slice spin-echo sequence was utilised using 6 isotropically distributed diffusion directions. One specimen was filled with a removable plastic polymer to improve the structural regularity of the heart. Results were obtained from both hearts in a time efficient manner, whilst maintaining tissue integrity and permitted extraction and quantification of myocardial orientation. Addition of the plastic polymer reduced myocardial disarray. Tractography of both hearts correlated with results found from previous studies. Feedback from pathology staff was positive regarding including the DTMRI protocol. Diffusion tensor imaging can be integrated into the conventional autopsy workflow without disruption to the autopsy process. The plastic polymer improved the ease of analysis as compared to the specimen without a plastic polymer. Although the technique is not at present ready for use in the autopsy process, this note indicates that it could in future be a viable tool to aid identification of paediatric cardiac disease.