Disaster victim identification: new applications for postmortem computed tomography

Abstract:  Mass fatalities can present the forensic anthropologist and forensic pathologist with a different set of challenges to those presented by a single fatality. To date radiography has played an important role in the disaster victim identification (DVI) process. The aim of this paper is to highlight the benefits of applying computed tomography (CT) technology to the DVI process. The paper begins by reviewing the extent to which sophisticated imaging techniques, specifically CT, have been increasingly used to assist in the analysis of deceased individuals. A small scale case study is then presented which describes aspects of the DVI process following a recent Australian aviation disaster involving two individuals. Having grided the scene of the disaster, a total of 41 bags of heavily disrupted human remains were collected. A postmortem examination was subsequently undertaken. Analysis of the CT images of all body parts ( n  = 162) made it possible not only to identify and side differentially preserved skeletal elements which were anatomically unrecognizable in the heavily disrupted body masses, but also to observe and record useful identifying features such as surgical implants. In this case the role of the forensic anthropologist and CT technology were paramount in facilitating a quick identification, and subsequently, an effective and timely reconciliation, of body parts. Although this case study is small scale, it illustrates the enormous potential for CT imaging to complement the existing DVI process.     

Facial Tissue Depths in Children with Cleft Lip and Palate

Cleft lip and palate (CLP) is a craniofacial malformation affecting more than seven million people worldwide that results in defects of the hard palate, teeth, maxilla, nasal spine and floor, and maxillodental asymmetry. CLP facial soft‐tissue depth (FSTD) values have never been published. The purpose of this research is to report CLP FSTD values and compare them to previously published FSTD values for normal children. Thirty‐eight FSTDs were measured on cone beam computed tomography images of CLP children (n = 86; 7–17 years). MANOVA and ANOVA tests determined whether cleft type, age, sex, and bone graft surgical status affect tissue depths. Both cleft type (unilateral/bilateral) and age influence FSTDs. CLP FSTDs exhibit patterns of variation that differ from normal children, particularly around the oronasal regions of the face. These differences should be taken into account when facial reconstructions of children with CLP are created.     

Blood aspiration as a vital sign detected by postmortem computed tomography imaging

Blood aspiration is a significant forensic finding. In this study, we examined the value of postmortem computed tomography (CT) imaging in evaluating findings of blood aspiration. We selected 37 cases with autopsy evidence of blood in the lungs and/or in the airways previously submitted to total-body CT scanning. The CT-images were retrospectively analyzed. In one case with pulmonary blood aspiration, biopsy specimens were obtained under CT guide for histological examination. In six cases, CT detected pulmonary abnormalities suggestive of blood aspiration, not mentioned in the autopsy reports. CT reconstructions provided additional data about the distribution and extent of aspiration. In one needle-biopsied case, the pulmonary specimens showed blood in the alveoli. We suggest the use of CT imaging as a tool complementary to traditional techniques in cases of blood aspiration to avoid misdiagnosis, to guide the investigation of lung tissue, and to allow for more evidence-based inferences on the cause of death.     

尸体断层影像学文献计量分析

尸体断层影像学(post-mortem cross-sectional imaging,PMCSI),也称虚拟解剖(virtopsy)或解剖画像(Ai),是法医学的革命性技术。较国际而言,我国PMCSI领域发展相对缓慢。进行系统的PMCSI文献计量分析研究,对于厘清国际PMCSI发展整体概貌和制定我国PMCSI发展战略方面,有着重要的现实意义。本文通过对2013-2019年PMCSI领域下27个专业术语不同组合进行在线文献搜索,并对文献的年份、作者、研究领域、发表杂志、作者单位、发表国家等系列指标进行了定性定量分析。分析结果表明世界PMCSI发展迅速:PMCSI已成为国际法医学的研究热点;瑞士、日本和英国PMCSI研究位居世界领先地位;尸体计算机断层扫描、尸体计算机断层扫描血管造影和尸体磁共振成像三个领域研究最为深入;PMCSI研究已得到相关学界的认同;法医日常检案中普及PMCSI是世界发展趋势。     

Introducing Computed Tomography Standards for Age Estimation of Modern Australian Subadults Using Postnatal Ossification Timings of Select Cranial and Cervical Sites,

Contemporary, population‐specific ossification timings of the cranium are lacking in current literature due to challenges in obtaining large repositories of documented subadult material, forcing Australian practitioners to rely on North American, arguably antiquated reference standards for age estimation. This study assessed the temporal pattern of ossification of the cranium and provides recalibrated probabilistic information for age estimation of modern Australian children. Fusion status of the occipital and frontal bones, atlas, and axis was scored using a modified two‐ to four‐tier system from cranial/cervical DICOM datasets of 585 children aged birth to 10 years. Transition analysis was applied to elucidate maximum‐likelihood estimates between consecutive fusion stages, in conjunction with Bayesian statistics to calculate credible intervals for age estimation. Results demonstrate significant sex differences in skeletal maturation (p < 0.05) and earlier timings in comparison with major literary sources, underscoring the requisite of updated standards for age estimation of modern individuals.     

CT、MRI在弥漫性轴索损伤法医学鉴定中应用价值分析

目的探讨CT和MRI检查方法在弥漫性轴索损伤(diffuse axonal injury,DAI)法医学鉴定中的应用价值。方法收集26例CT和MRI影像资料齐全的DAI鉴定资料进行回顾性分析,比较CT和MRI两种方法对DAI病灶检出率的差异,分析DAI病灶检出数量与法医学鉴定结果之间的关系。结果 26例经MRI检出DAI病灶787个,经CT检出DAI病灶32个,MRI对DAI病灶的敏感度显著高于CT(P0.01)具有统计学意义。26例DAI鉴定的伤残等级数值与影像学检查发现的病灶数量之间存在负相关(r=-0.908,P0.01)。结论 MRI检查对DAI病灶的检出率较CT检查具有明显优势,可为DAI诊断提供更为准确的依据,在法医临床学鉴定中具有重要的应用价值。     

UBM、SL-OCT及房角镜检查前房角结构的比较

目的 探讨超声生物显微镜（ultrasound biomicroscope,UBM）、裂隙灯前节光学相干断层成像（slit lamp optical coherence tomography,SL-OCT）与房角镜检查房角后退和房角关闭的一致性. 方法 在同一暗室中对被检查眼上方、下方、颞侧、鼻侧4个方位进行UBM、SL-OCT及房角镜检查,记录前房角情况,应用x2检验和Kappa检验对3种检查方法就房角关闭、房角后退的检查结果一致性进行比较. 结果 应用UBM、SL-OCT及房角镜检查判断房角关闭和房角后退,3种检查方法差异无统计学意义（P＞0.05）,UBM与房角镜检查房角后退结果一致性更好（Kappa值0.882）,而SL-OCT与房角镜检查房角后退结果一致性一般（Kappa值0.624）. 结论 以房角镜检查作为标准,对房角后退的判断UBM优于SL-OCT;对房角关闭的判断,UBM、SL-OCT及房角镜检查一致性均良好.     

Use of Craniofacial Superimposition in Historic Investigation

A skeleton discovered in Grand Forks, North Dakota was purported to belong to Clelland “Clell” Miller, a James‐Younger gang member, who was killed during the Northfield Bank robbery on September 7, 1876. A 3‐D image from a computer tomography (CT) scan of the skull was obtained, and a craniofacial superimposition was conducted to determine if the skull could belong to Miller. The superimposition method used in this case was to overlay the CT image of the skull onto Miller's postmortem photograph. In addition to the craniofacial superimposition, the images were juxtaposed to compare similarities or differences in facial morphology between the skull and photograph. Superimposition methods can be used to exclude identifications; however, they should not be used as a conclusive method for identification. In this case, there were sufficient similarities between the skull and Miller's photograph; therefore, the skull could not be eliminated as possibly being that of Miller.