The value of postmortem computed tomography as an alternative for autopsy in trauma victims: a systematic review

The aim of this study was to assess the role of postmortem computed tomography (PMCT) as an alternative for autopsy in determining the cause of death and the identification of specific injuries in trauma victims. A systematic review was performed by searching the EMBASE and MEDLINE databases. Articles were eligible if they reported both PMCT as well as autopsy findings and included more than one trauma victim. Two reviewers independently assessed the eligibility and quality of the articles. The outcomes were described in terms of the percentage agreement on causes of death and amount of injuries detected. The data extraction and analysis were performed together. Fifteen studies were included describing 244 victims. The median sample size was 13 (range 5–52). The percentage agreement on the cause of death between PMCT and autopsy varied between 46 and 100%. The overall amount of injuries detected on CT ranged from 53 to 100% compared with autopsy. Several studies suggested that PMCT was capable of identifying injuries not detected during normal autopsy. This systematic review provides inconsistent evidence as to whether PMCT is a reliable alternative for autopsy in trauma victims. PMCT has promising features in postmortem examination suggesting PMCT is a good alternative for a refused autopsy or a good adjunct to autopsy because it detects extra injuries overseen during autopsies. To examine the value of PMCT in trauma victims there is a need for well-designed and larger prospective studies

Non-invasive or minimally invasive autopsy compared to conventional autopsy of suspected natural deaths in adults: a systematic review

Objectives: Autopsies are used for healthcare quality control and improving medical knowledge. Because autopsy rates are declining worldwide, various non-invasive or minimally invasive autopsy methods are now being developed. To investigate whether these might replace the invasive autopsies conventionally performed in naturally deceased adults, we systematically reviewed original prospective validation studies. Materials and methods: We searched six databases. Two reviewers independently selected articles and extracted data. Methods and patient groups were too heterogeneous for meaningful meta-analysis of outcomes. Results: Sixteen of 1538 articles met our inclusion criteria. Eight studies used a blinded comparison; ten included less than 30 appropriate cases. Thirteen studies used radiological imaging (seven dealt solely with non-invasive procedures), two thoracoscopy and laparoscopy, and one sampling without imaging. Combining CT and MR was the best non-invasive method (agreement for cause of death: 70 %, 95%CI: 62.6; 76.4), but minimally invasive methods surpassed non-invasive methods. The highest sensitivity for cause of death (90.9 %, 95%CI: 74.5; 97.6, suspected duplicates excluded) was achieved in recent studies combining CT, CT-angiography and biopsies. Conclusion: Minimally invasive autopsies including biopsies performed best. To establish a feasible alternative to conventional autopsy and to increase consent to post-mortem investigations, further research in larger study groups is needed. Key points: • Health care quality control benefits from clinical feedback provided by (alternative) autopsies. • So far, sixteen studies investigated alternative autopsy methods for naturally deceased adults. • Thirteen studies used radiological imaging modalities, eight tissue biopsies, and three CT-angiography. • Combined CT, CT-angiography and biopsies were most sensitive diagnosing cause of death

Postmortem computed tomography age assessment of juvenile dentition:comparison against traditional OPT assessment

Age estimation is one of the primary demographic features used in the identification of juvenile remains. Determining the accuracy and repeatability of age estimations based on postmortem computed tomography (PMCT) data compared with those using conventional orthopantomography (OPT) images is important to validate the use of PMCT as a single imaging technique in forensic and disaster victim identification (DVI). In this study, 19 juvenile mandibles and maxilla of known age underwent both OPT and PMCT. Three raters then estimated dental age using the resulting images and 3D reconstructions. This assessment showed excellent agreement between the age estimations using the two techniques for all three observers. PMCT also offers a greater range of measurements for both the dentition and the whole human skeleton using a single image acquisition and therefore has the potential to improve both the speed and accuracy of age estimation

Post-mortem computed tomography and 3D imaging:anthropological applications for juvenile remains

Anthropological examination of defleshed bones is routinely used in medico-legal investigations to establish an individual's biological profile. However, when dealing with the recently deceased, the removal of soft tissue from bone can be an extremely time consuming procedure that requires the presence of a trained anthropologist. In addition, due to its invasive nature, in some disaster victim identification scenarios the maceration of bones is discouraged by religious practices and beliefs, or even prohibited by national laws and regulations. Currently, three different radiological techniques may be used in the investigative process; plain X-ray, dental X-ray and fluoroscopy. However, recent advances in multi-detector computed tomography (MDCT) mean that it is now possible to acquire morphological skeletal information from high resolution images, reducing the necessity for invasive procedures. This review paper considers the possible applications of a virtual anthropological examination by reviewing the main juvenile age determination methods used by anthropologists at present and their possible adaption to MDCT

Limited post-mortem examination. An alternative and viable way to avoid full examination?

A complete post-mortem examination is required in most medicolegal investigation systems. Though uncommon, some jurisdictions allow limited post-mortem examination if it is adequate to fulfil the death inquiries. One such jurisdiction is the state of Queensland with the commencement of the new Coroners Act. It permits the Coroner to order limited post-mortem examination confined to a specific region or regions of the body based on the circumstances received from the investigating police.There is a paucity of literature comparing the completeness of limited post-mortem examination compared with complete examination. We aim to study whether limited post-mortem examination can partially replace complete examination in specific circumstances. Archival post-mortem reports with history are obtained. Cases where obvious complete post-mortem examination is required [e.g., sudden infant death syndrome (SIDS), homicide, medicolegal hospital cases, pregnancy deaths], decomposed and skeletonized cases are excluded from the study. The region or regions (head, neck, chest, or abdomen) most appropriate for examination are derived from studying the circumstances given.Three hundred and fifty-one cases were reviewed, of which 136 were found to be suitable to be incorporated into the study. Discrepancies were present in 17.7% (n≤24) of the cases (15 cases due to different cause of death, seven due to changes in interpretation, and two where pathology may be significant to the family). When classified according to mode of death, the percentages were 46.4%, 11.1%, and 9.3% for the accident, natural, and suicide groups, respectively. When compared to region examined, the discrepancies were 9 out of 18 for head, 1 out of 20 for neck, 5 out of 70 for chest, none of out 2 for extremities, and 3 out of 4 for abdomen.The study showed a significantly high percentage of discrepancies when limited post-mortem examination was performed. The missed information may impede medicolegal inquiries, police investigation, and interfere with the course of justice. Significant information about familial disease may be missed

Effect of coherent noise on single-station direction of arrival estimation

The original publication can be found at www.springerlink.comPolarization analysis of multi-component seismic data is used in both exploration seismology and earthquake seismology. In single-station polarization processing, it is generally assumed that any noise present in the window of analysis is incoherent, i.e., does not correlate between components. This assumption is often violated in practice because several overlapping seismic events may be present in the data. The additional arrival(s) to that of interest can be viewed as coherent noise. This paper quantifies the error because of coherent noise interference. We first give a general theoretical analysis of the problem. A simple mathematical wavelet is then used to obtain a closed-form solution to the principal direction estimated for a transient incident signal superposed with a time-shifted, unequal amplitude version of itself, arriving at an arbitrary angle to the first wavelet. The effects of relative amplitude, arrival angle, and the time delay of the two wavelets on directional estimates are investigated. Even for small differences in angle of arrival, there may be significant error (>10°) in the azimuth estimate.Stewart Alan Greenhalgh, Bing Zhou and Matthew Rutt