Invited article Optical coherence tomography of re-pressurised porcine coronary arteries: A systematic study $ Asif Adnan a,n , Claire Robinson b , Mike Biggs c , Shiju Joseph a , Bruno Morgan b , Guy Rutty c , David Adlam a a Department of Cardiovascular Sciences & NIHR Cardiovascular BRU, University of Leicester, Groby Road, Glenfield Hospital, Leicester LE3 9QP, UK b Department of Radiology and Imaging, Level 2, Windsor Building, Leicester Royal Infirmary, Leicester LE1 5WW, UK c East Midlands Forensic Pathology Unit, University of Leicester, Level 3, RKCSB, Leicester Royal Infirmary, Leicester LE2 7LX, UK article info Article history: Received 7 September 2015 Received in revised form 26 October 2015 Accepted 7 November 2015 Available online 10 November 2015 Keywords: Forensic imaging Optical coherence tomography Coronary artery disease Post-mortem imaging Minimally invasive autopsy abstract Cardiovascular death is the most frequently reported cause of adult natural death in autopsy reports in the UK. However, the approach used for diagnosing coronary artery disease at autopsy is largely based on visual assessment of coronary artery cross sections to determine the severity of stenosis. This is subject to criticism and heterogeneity. Objective: We investigated the potential role of a novel intravascular imaging technique, optical co- herence tomography (OCT), in post-mortem diagnosis of coronary artery disease and what effect re- pressurisation has on vessel dimensions, as measured by OCT. Our long term aim is to investigate the role of OCT as a minimally invasive autopsy tool. Materials and methods: We used several ex-vivo porcine hearts to develop the techniques. Subsequently, 6 coronary arteries were used for detailed experiments. Vessels were gradually re-pressurised using normal saline and clinical coronary pressure wire and OCT systems were used for recording the pressure and intracoronary imaging. Results: Our data showed re-pressurisation significantly alters the vessel dimensions. The mean cross sectional area increased from 3.3 to 8.4 mm 2 proximally and from 2.5 to 7.4 mm 2 distally. Conclusion: We conclude that OCT in the ex-vivo setting is feasible and re-pressurisation significantly alters vascular dimensions. This implies, there might be significant discrepancies between the true se- verities of stenosis in life and that which is determined by visual estimation during autopsy in the collapsed vessels. OCT of re-pressurised vessel can overcome this issue and has the potential to improve the accuracy of post-mortem assessment of coronary artery disease. & 2015 Elsevier Ltd. All rights reserved. 1. Introduction Despite a worldwide decreasing trend, England and Wales continue to have a high autopsy rate, reported as 22% of all re- gistered deaths [1]. This is much higher than Scotland and Northern Ireland (10% and 9%) and most other European countries [1–3]. Most (nearly 95%) of these 110,000 autopsies performed every year are coronial autopsies [4] and vast majority of these autopsies have a natural cause of death of which ischaemic heart disease is the most frequent diagnosis [5]. The post-mortem diagnosis of coronary artery disease is based on a probabilistic approach by determining severity of stenosis in the major epicardial arteries by direct observation of cross sections [6,7]. These vessels may be collapsed, being devoid of blood flow and pressure after the cessation of circulation. This approach is therefore subject to significant variability [8] due both to the limitations of a visual assessment of a coronary luminal stenosis exacerbated by the differential effects of depressurisation on both normal and abnormal coronary anatomy. New approaches, capable of demonstrating the severity of coronary disease in a re- pressurised vessel therefore have the potential to improve the accuracy of a post mortem diagnosis of coronary artery disease. Optical coherence tomography (OCT) is an imaging modality that uses near infrared light interferometry and is capable of showing tissue microstructure. In 1991, Huang et al. first Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jofri Journal of Forensic Radiology and Imaging http://dx.doi.org/10.1016/j.jofri.2015.11.004 2212-4780/& 2015 Elsevier Ltd. All rights reserved. ☆ All authors contributed to the conception and design of the study. AA and CR performed the practical experiments. AA performed the data analysis and wrote the manuscript along with DA. All authors contributed to the manuscript with their various inputs. n Correspondence to: Department of Cardiovascular Sciences, University of Lei- cester, Clinical sciences Wing, Glenfield Hospital, Groby Road, Leicester LE3 9QP, UK. E-mail addresses: kaa31@le.ac.uk (A. Adnan), Claire.Robinson@uhl-tr.nhs.uk (C. Robinson), mb614@le.ac.uk (M. Biggs), sgj5@le.ac.uk (S. Joseph), bm11@le.ac.uk (B. Morgan), gnr3@le.ac.uk (G. Rutty), da134@le.ac.uk (D. Adlam). Journal of Forensic Radiology and Imaging 4 (2016) 53–57