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SummaryBackgroundEngland and Wales have one of the highest frequencies of autopsy in the world. Implementation of post-mortem CT (PMCT), enhanced with targeted coronary angiography (PMCTA), in adults to avoid invasive autopsy would have cultural, religious, and potential economic benefits. We aimed to assess the diagnostic accuracy of PMCTA as a first-line technique in post-mortem investigations.MethodsIn this single-centre (Leicester, UK), prospective, controlled study, we selected cases of natural and non-suspicious unnatural death referred to Her Majesty's (HM) Coroners. We excluded cases younger than 18 years, known to have had a transmittable disease, or who weighed more than 125 kg. Each case was assessed by PMCTA, followed by autopsy. Pathologists were masked to the PMCTA findings, unless a potential risk was shown. The primary endpoint was the accuracy of the cause of death diagnosis from PMCTA against a gold standard of autopsy findings, modified by PMCTA findings only if additional substantially incontrovertible findings were identified.FindingsBetween Jan 20, 2010, and Sept 13, 2012, we selected 241 cases, for which PMCTA was successful in 204 (85%). Seven cases were excluded from the analysis because of procedural unmasking or no autopsy data, as were 24 cases with a clear diagnosis of traumatic death before investigation; 210 cases were included. In 40 (19%) cases, predictable toxicology or histology testing accessible by PMCT informed the result. PMCTA provided a cause of death in 193 (92%) cases. A major discrepancy with the gold standard was noted in 12 (6%) cases identified by PMCTA, and in nine (5%) cases identified by autopsy (because of specific findings on PMCTA). The frequency of autopsy and PMCTA discrepancies were not significantly different (p=0·65 for major discrepancies and p=0·21 for minor discrepancies). Cause of death given by PMCTA did not overlook clinically significant trauma, occupational lung disease, or reportable disease, and did not significantly affect the overall population data for cause of death (p≥0·31). PMCTA was better at identifying trauma and haemorrhage (p=0·008), whereas autopsy was better at identifying pulmonary thromboembolism (p=0·004).InterpretationFor most sudden natural adult deaths investigated by HM Coroners, PMCTA could be used to avoid invasive autopsy. The gold standard of post-mortem investigations should include both PMCT and invasive autopsy.FundingNational Institute for Health Research.

Post-mortem computed tomography with coronary angiography (PMCTA) could have a role in the investigation of sudden natural death. This study assesses the accuracy of targeted coronary PMCTA, using both air and iodinated contrast media, to provide sensitivity and specificity for critical stenosis (CS) on a segmental basis, based on a gold standard of 3-5 mm serial sections of the coronary arteries using macroscopic and histological techniques. Assessment of stenosis at 1 mm intervals on PMCTA was compared with the data from pathological analysis. Stenosis was defined as "critical" when the stenotic region reaches ≥75 %. Regions were defined every 20 mm or by a clear change in stenosis. Discrepancies were defined as significant if only one test showed CS. Five cases with 25 vessels with 124 regions were assessed. PMCTA was unable to identify plaque hemorrhage or dissection (but this was normally associated with CS). Eighteen segments had significant discrepancies, giving a sensitivity and specificity of 50 and 91.5 %. When an alternative gold standard was constructed by excluding regions beyond a CS (five cases), taking PMCTA as correct where a heavily calcified vessel opens under contrast injection (four cases), and correcting for misregistration of distance (one case), the sensitivity rose to 85.7 %. There was complete agreement when the right or left coronary arteries are assessed as a whole. This study shows that PMCTA is not a perfect replacement for histological examination of coronary vessels, but may have a role in routine post-mortem investigation.

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Bodies found immersed in water can pose difficulties to the investigating authorities. Pathologists may be assisted with the diagnosis by the use of tests such as the analysis for diatoms or the levels of strontium in the blood, although there is a recognised level of uncertainty associated with these tests. Recent work from Japan has shown that using molecular approaches, most recently real-time polymerase chain reaction (PCR) assays with TaqMan probes for bacterioplankton, it is possible to undertake rapid, less laborious, high throughput tests to differentiate freshwater from marine bacterioplankton and in doing so provide a molecular diagnostic test to assist in the diagnosis of drowning. We report the experiences of a United Kingdom forensic pathology unit in the use of this PCR based system for the diagnosis of drowning. We applied this technique to 20 adult and child cadavers from 4 bath, 12 freshwater, 2 brackish and 2 salt water scenes both from within the United Kingdom and abroad. Drowning was concluded to be the cause of death in 16 of these 20 cases and the PCR method supported this conclusion in 12 of these 16 cases. The PCR did not provide evidence of drowning in the four cases where death was from other causes. We illustrate that this PCR method provides a rapid diagnostic supportive test for the diagnosis of drowning that can be applied to United Kingdom autopsy practice.

Whilst the literature continues to report on advances in the use of post-mortem computed tomography (PMCT), particularly in relation to post-mortem angiography, there are few papers published that address the diagnostic problems related to post-mortem changes in the lungs and ventilation. We present a development of previous methods to achieve ventilated PMCT (VPMCT). We successfully introduced a supraglottic airway in 17/18 cases without causing overt damage, despite rigor mortis. Using a clinical portable ventilator, we delivered continuous positive airway pressure to mimic clinical breath-hold inspiratory scans. This caused significant lung expansion and a reduction in lung density and visible normal post-mortem changes. All thoracic pathology identified at autopsy, including pneumonia, was diagnosed on VPMCT in this small series. This technique provides a rapid form of VPMCT, which can be used in both permanent and temporary mortuaries, allowing for the post-mortem radiological comparison of pre-ventilation and post-ventilation images mimicking expiratory and inspiratory phases. We believe that it will enhance the diagnostic ability of PMCT in relation to lung pathology.

Social, cultural and practical barriers to conventional invasive autopsy have led to considerable interest in the development of minimally invasive radiological techniques as an alternative to the invasive autopsy for determining the cause of death. Critical to accurate diagnosis in this context is detailed examination of coronary anatomy and pathology. Current computed tomography and magnetic resonance imaging approaches have significantly advanced minimally invasive autopsy practice but have limited spatial resolution. This prohibits assessment at a microscopic level, meaning that histological assessment is still required for detailed analysis of, for example, coronary plaque rupture or dissection. Coronary optical coherence tomography (OCT) is used in the living during percutaneous coronary interventions to provide high-resolution coronary imaging, but this technique for obtaining virtual histology has not, to date, been translated into minimally invasive autopsy practice. We present a first description of minimally invasive post-mortem coronary OCT and discuss the potential for this technique to advance current practice.

Ventilated post-mortem computed tomography (VPMCT) has been shown to achieve lung expansion in cadavers and has been proposed to enhance the diagnosis of lung pathology. Two key problems of the method of ventilation have been identified: firstly, the presence of head and neck rigor making airway insertion challenging and, secondly, air leak, if there is not a good seal around the airway, which diminishes lung expansion and causes inflation of the stomach. Simple procedures to insert a 'definitive' cuffed airway, which has a balloon inflated within the trachea, are therefore desirable. This study aims to test different procedures for inserting cuffed airways in cadavers and compare their ventilation efficacy and to propose a decision algorithm to select the most appropriate method. We prospectively tested variations on two ways of inserting a cuffed airway into the trachea: firstly, using an endotracheal tube (ET) approach, either blind or by direct visualisation, and, secondly, using a tracheostomy incision, either using a standard tracheostomy tube or shortened ET tube. We compare these approaches with a retrospective analysis of a previously reported series using supraglottic airways. All techniques, except 'blind' insertion of ET tubes, were possible with adequate placement of the airway in most cases. However, achieving both adequate insertion and a complete tracheal seal was better for definitive airways with 56 successful cases from 59 (95 %), compared with 9 cases from 18 (50 %) using supraglottic airways (p < 0.0001). Good lung expansion was achieved using all techniques if the airway was adequately positioned and achieved a good seal, and there was no significant chest pathology. We prefer inserting a shortened ET tube via a tracheostomy incision, as we find this the easiest technique to perform and train. Based on our experience, we have developed a decision algorithm to select the most appropriate method for VPMCT.