CT技术在法医人类学研究中应用的进展

近年来,将计算机断层扫描(CT)等影像学新技术应用于法医人类学个体识别的研究受到国内外法医人类学家的重视。CT具有清晰快速的成像能力以及强大的后处理功能,无需骨骼前处理就能提供高分辨率模型图像,对法医人类学具有重要的研究和应用价值。本文就CT技术在法医人类学研究中应用的进展进行综述,以期为相关研究和实践提供参考和借鉴。     

Time-related changes in cardiac ct images of rabbits died from four kinds of execution

Objective To explore the feasibility and appropriate parameters for estimating postmortem interval (PMI) through time-related CT imaging into dynamically monitoring the cardiac changes of rabbits died from four kinds of execution. Methods The experimental rabbits were executed with four disposals of air embolism, strangulation, drowning and hemorrhagic shock. The dead rabbits were observed of their hearts with CT scanning every 6 hours within 120h from the death moment, having the obtained time-different CT images and mean CT values examined. With the cardiac average CT values of rabbits died from discrepant execution, four relevant regression equations were established against the elapsing time (i.e. PMI). Results The CT images of post-death cardiac tissue of rabbits died from one of four executions did change regularly with the PMI elongating, showing consistent with the autopsy verification. The binomial regressive equations were established between the post-death cardiac average CT value and PMI from four executions, demonstrating statistically significant (P<0.05). Conclusion The postmortem cardiac CT imaging into PMI analysis, plus the relating regression equation, provides a new objective visual quantitative approach and reference for forensic medicine to infer the time of death. © 2021, Editorial Office of Forensic Science and Technology. All rights reserved.     

新鲜鼻骨骨折CT诊断指标探讨

法医鉴定工作中,需要明确判断鼻骨骨折为新鲜形成,方可作为人体损伤鉴定的依据.通过案例追踪复查与已知陈旧鼻骨骨折对照及临床表现等方法,依据骨折断端锐利、骨折部位粘膜肿胀、软组织内有小片状低密度影等CT影像表现,结合伤后鼻面部肿胀、鼻出血、鼻腔通气不畅等临床表现作为新鲜鼻骨骨折的影像诊断指标.工作中,须重视鼻骨骨折新旧伤的...     

根据骨盆CT片特征指标进行同一认定的研究

目的选择骨盆CT片上的特征指标,建立逐步回归方程,探讨其在法医学同一认定中的应用价值。方法收集160名不同被检查者骨盆CT影像片各1张,70名被检查者不同次骨盆CT影像片各2张。选择并测量骨盆CT片上的14项指标值,分别计算不同人随机分组相同测量指标的组间的差值,以及相同人不同次测量指标间的差值,运用二分类logistic逐步回归分析,建立各项指标的一元回归方程和多项指标的多元回归方程,并对方程进行盲测检验。结果建立的14个一元方程中同一认定的正确率在61.1%(骶骨耳状面后缘宽)~80.5%(第一骶椎平面左右髂骨前端间距)之间;建立的6个多元回归方程的正确率在80.5%~93.8%之间。盲测准确率为100%。结论本文在CT片上选择的14项特征指标可以用于同一认定,在使用时应尽可能选用多元指标以得到更准确的结果。     

Identification of unknown bodies by using CT images of frontal sinus

The aim of the study was to define a simple system for the identification of unknown bodies by using CT images of frontal sinus and to discuss whether it was worth to add measurements to the system or not. The system was including simple features as F (presence or absence of frontal sinus), S (intersinus and intrasinus septum) and S (scalloping), and named as FSS system. Measurements selected for the study were width, height, anteroposterior length, total width of two sinuses, the distance between the highest points of the two sinuses and the distance of each sinus to its maximum lateral limit. The study was conducted retrospectively on the paranasal CT scans of 100 cases (38 male and 62 female) who had no apparent sinonasal pathology. All the features and measurements were coded according to the system defined by the authors for each case and coded formulas were compared. At least 93% of the formulas could be eliminated for a case by using FSS system. The rate of success was increased to 98% by adding measurements. Contrary to objective criteria of FSS system, measurements were prone to bias. Therefore, in practice success rate would be expected to be lower than calculated. In the study population, instead of making 100 measurements, eliminating the most of the cases with FSS system and later discriminating the rest by pattern matching was seen logical.     

CT在法医病理学中的应用与展望

计算机断层扫描(CT)能够对不同密度的人体组织进行成像,在疾病和损伤的检验中具有重要的应用价值,随着CT技术的不断发展和逐步成熟,它可以对组织脏器进行容积再现、多层面重建、最大密度投影、表面遮盖显示等后处理,在肿瘤、血管畸形等疾病的诊断,骨折、关节异位、脏器破裂、出血等损伤的检验,枪弹、爆炸碎片、吸入物等体内异物的检验中具有重要的应用价值。目前已经有不少学者将其应用到相关研究领域当中。本文对近几年国内外应用CT技术进行法医病理学研究的情况进行综述,以便法医病理学研究者了解CT在法医病理学领域中的应用及研究现状,能够为今后的法医病理学科学研究和实践工作提供新的思路。     

Correlation Between Average Tissue Depth Data and Quantitative Accuracy of Forensic Craniofacial Reconstructions Measured by Geometric Surface Comparison Method

Accuracy is the most important factor supporting the reliability of forensic facial reconstruction (FFR) comparing to the corresponding actual face. A number of methods have been employed to evaluate objective accuracy of FFR. Recently, it has been attempted that the degree of resemblance between computer‐generated FFR and actual face is measured by geometric surface comparison method. In this study, three FFRs were produced employing live adult Korean subjects and three‐dimensional computerized modeling software. The deviations of the facial surfaces between the FFR and the head scan CT of the corresponding subject were analyzed in reverse modeling software. The results were compared with those from a previous study which applied the same methodology as this study except average facial soft tissue depth dataset. Three FFRs of this study that applied updated dataset demonstrated lesser deviation errors between the facial surfaces of the FFR and corresponding subject than those from the previous study. The results proposed that appropriate average tissue depth data are important to increase quantitative accuracy of FFR.     

法医活体损伤鉴定中观察急性血肿CT显示不同密度改变的原因分析

作者总结、分析了50例CT显示高密度结构的急性脑出血和16例显示低密度结构的急性腹腔积血的CT征象所出现的不同密度高低改变的原因,其目的是提高法医活体损伤鉴定对急性出血CT检查可显示不同密度改变的认识,现总结如下:l资料和方法1·1资料50例急性脑出血中,男37例,女13例,年龄为一个扫描单元,需3~4个扫描单元完成整个腹部扫描,扫描时吩咐患者屏气,窗宽选择300Hu,窗位35Hu,120kV,250mA,选择直径为5mm的圆形光标进行腹腔积血的CT值测量。2结果急性脑出血后2日内血肿的CT值本组为53~69Hu,平均60·7Hu,肉眼观察CT图像中显示的血肿密度…     

眼眶爆裂骨折的CT表现及法医学鉴定分析

目的研究眼眶爆裂骨折的CT表现特点及其法医学鉴定问题。方法对76例眼眶爆裂骨折的临床法医学鉴定案例进行回顾性分析、总结。结果单纯头部CT以及X线检查诊断眼眶爆裂骨折漏诊率较高,其中CT诊断阳性率高于X线;眼部CT检查是诊断眼眶爆裂骨折的首选方法。76例骨折中以眶内侧壁骨折多见,其次为眶下壁骨折。CT直接征象主要表现为眶壁骨质连续性中断和眶壁移位,间接征象主要为骨折处积血和软组织增厚;临床表现以眼周瘀斑、肿胀、视力下降及复视为主。眼眶爆裂骨折对伤眼视力影响不明显,患者伤后视力多在0.8以上,但是容易出现复视;损伤程度以轻伤为主。结论单纯头部CT及X线检查诊断眶壁爆裂骨折有局限性,对眼部损伤患者,建议法医鉴定时将眶部CT检查作为常规;眶壁骨折对伤眼视力影响不明显,但是容易出现复视,法医鉴定时应引起注意。