多层螺旋CT在交通事故损伤生物力学分析中的应用

目的探讨多层螺旋CT(multi-slice computed tomography,MSCT)及三维重建技术在交通事故损伤生物力学分析方面的应用价值。方法以真实案例为基础,通过MSCT扫描获得尸体断层影像,进行三维图像重建,结合尸体解剖、车辆勘验等结果综合分析交通事故撞击、碾压和挤压等行为方式中的生物力学过程,并与尸体解剖结果进行对比。结果 MSCT和三维重建获得了不同受力部位骨折的位置、骨折线走向以及骨内碎裂状况等原位特征,其对于骨折的精细还原优于尸体解剖。结论 MSCT和三维重建技术在原位特征的再现、图像的易操作性以及证据的保全等方面凸显优势,可对道路交通事故损伤生物力学分析起补充和引导作用。     

多层螺旋CT与三维重建技术在法医损伤学中的应用

影像学技术发展迅速．已经成为临床诊断、治疗不可或缺的有效工具。利用MSCT与三维重建技术进行虚拟解剖,因为具有非破坏性、可显示特殊部位损伤形态、分析快速且便捷、便于证据保存和出示等特点在法医学尸体解剖中日益凸显优势．在法医损伤学研究及实践鉴定过程中具有较高的应用价值。文章综述了利用MSCT与三维重建技术在锐器伤、钝器伤、高坠伤、交通伤等实践领域的研究成果,并通过实践检案中遇到的典型案例,探讨多层螺旋CT与三维重建技术在法医学损伤鉴定中的应用价值。     

Visualization and quantification of air embolism structure by processing postmortem MSCT data

Venous air embolism (VAE) is an often occurring forensic finding in cases of injury to the head and neck. Whenever found, it has to be appraised in its relation to the cause of death. While visualization and quantification is difficult at traditional autopsy, Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) offer a new potential in the diagnosis of VAE. This paper reports the findings of VAE in four cases of massive head injury examined postmortem by Multislice Computed Tomography (MSCT) prior to autopsy. MSCT data of the thorax were processed using 3D air structure reconstruction software to visualize air embolism within the vascular system. Quantification of VAE was done by multiplying air containing areas on axial 2D images by their reconstruction intervals and then by summarizing the air volumes. Excellent 3D visualization of the air within the vascular system was obtained in all cases, and the intravascular gas volume was quantified.     

猪离体心脏冠状动脉的MSCT造影

目的 通过对猪离体心脏冠状动脉进行多层螺旋CT（MSCT）造影成像,探索离体心脏血管造影技术的具体操作方法及参数.方法 应用自主改装的血管造影装置,分别将脂溶性和水溶性对比剂以不同灌注量（50、60、70 mL）和不同灌注-成像时间间隔（5、10、20 min）灌注猪离体心脏冠状动脉,进行MSCT扫描和三维图像效果比较,由2名放射科医生对各组的造影成像效果进行评估和记录,并对结果进行统计学分析. 结果 脂溶性对比剂对冠状动脉周围脂肪造成浸润和破坏而影响造影成像效果,而水溶性对比剂未出现类似结果.灌注-成像时间间隔为5 min,且灌注量为60 mL和70 mL时造影成像质量最佳. 结论 本研究的血管造影参数为后期开展尸体在体心脏冠脉造影奠定基础.     

Image-guided virtual autopsy findings of gunshot victims performed with multi-slice computed tomography and magnetic resonance imaging and subsequent correlation between radiology and autopsy findings

Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot's wound ballistic effects was not possible. The aim of our study was to evaluate whether the progress in imaging techniques over the last years has made it possible to establish an observer-independent and reproducible forensic assessment using multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) technologies for the documentation and analysis of gunshot wounds. The bodies of eight gunshot victims were scanned by MSCT and by MRI; the data of these imaging techniques were post-processed on a workstation, interpreted and subsequently correlated with the findings of classical autopsy. With the spiral CT and MRI examinations and the subsequent 2D multi-planar reformation (MPR) and 3D shaded surface display (SSD) reconstruction, the entire gunshot-created complex skull fractures and brain injuries (such as wound channels and deeply-driven bone splinters) could be documented in complete and graphic detail. CT and MRI also documented vital reaction to the gunshot by demonstrating air emboli in the heart and blood vessels and the classic pattern of blood aspiration to the lung. Gunshot residues deposited within and under the skin were visible. In conclusion, we think that the radiological methods of MSCT and MRI have the potential to become a routine "virtual autopsy" tool in the future. Bullets and relevant histological samples from specific sites then might be won in image-guided minimally invasive fashion via percutaneous biopsy. The rapid application of developing radiological methods may lead to new horizons in forensic documentation and intravital as well as postmortem examination.     

Application of 3D documentation and geometric reconstruction methods in traffic accident analysis: with high resolution surface scanning, radiological MSCT/MRI scanning and real data based animation

The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.     

道路交通事故死者MSCT扫描与尸体解剖结果的比较

目的使用多层螺旋CT(MSCT)对道路交通事故中死者的损伤进行观察分析,探索MSCT在道路交通事故鉴定中的应用价值。方法对10例道路交通事故死亡者进行全身MSCT扫描,随后进行系统尸体解剖,并将两者的结果进行对比,分析两者在获取交通事故损伤信息方面的优点和不足。结果 MSCT可以清晰显示身体各部位骨折三维形态特征,并可检查到全身各部位的积气,相对于尸体解剖优势明显;但对于器官和软组织损伤的检测,MSCT的分辨率有限。结论对于道路交通事故死者,确定死亡方式和死亡原因的最好方法是联合进行MSCT检查和尸体解剖。     

Use of multislice computed tomography in disaster victim identification--advantages and limitations

After a mass fatality incident (MFI), all victims have to be rapidly and accurately identified for juridical reasons as well as for the relatives' sake. Since MFIs are often international in scope, Interpol has proposed standard disaster victim identification (DVI) procedures, which have been widely adopted by authorities and forensic experts. This study investigates how postmortem multislice computed tomography (MSCT) can contribute to the DVI process as proposed by Interpol. The Interpol postmortem (PM) form has been analyzed, and a number of items in sections D and E thereof have been postulated to be suitable for documentation by CT data. CT scans have then been performed on forensic cases. Interpretation of the reconstructed images showed that indeed much of the postmortem information required for identification can be gathered from CT data. Further advantages of the proposed approach concern the observer independent documentation, the possibility to reconstruct a variety of images a long time after the event, the possibility to distribute the work by transmitting CT data digitally, and the reduction of time and specialists needed at the disaster site. We conclude that MSCT may be used as a valuable screening tool in DVI in the future.     

Virtual autopsy and forensic anthropology of a mummified fetus: a report of one case

A jar containing the mummified body of a fetus was found in a bush near a building. Full-body multislice computed tomography (MSCT) was performed prior to autopsy to study the bones and internal organs. Age was estimated by measuring femoral and tibial lengths and examining the temporal and occipital bones. The results were then compared with the autopsy and histopathological findings. MSCT was superior to autopsy for examination of the bones and internal organs. Autopsy was difficult because of the fragility of the dried corpse. MSCT determined the gestational age of the fetus and excluded skeletal abnormalities. Estimated age was similar with the two methods used. However, the major advantage of MSCT was rapid measurement of bones or anatomical regions which are difficult to examine during autopsy and which required specific preparation for further anthropological study. This case report illustrates the possibilities offered by MSCT for studying mummified bodies, even fetuses.     

多层螺旋CT、普通CT和X线在骨折法医学鉴定中的应用

目的比较多层螺旋CT（MSCT）、普通CT与X线3种检查法,评价它们在骨折法医鉴定中的应用价值。方法对366例受检者（已接受其他影像学检查）行MSCT薄层扫描并行SSD,透明化X线模拟投影和MPR处理。统计分析MSCT、CT常规与X线检查在各部位骨折中的诊断正确率和漏、误诊率并行χ2检验。结果鼻骨、肋骨、四肢及关节、眶骨、颅骨骨折MSCT诊断正确率明显高于普通CT或X线（P〈0.01）。MSCT与普通CT对脊柱骨折的诊断正确率无统计学差异（P〉0.05）。MSCT、普通CT与X线的总体诊断正确率分别为99.45%、70.27%和59.17%。常规CT、X线与MSCT诊断结果间存在显著统计学差异（P〈0.001）。结论MSCT对骨折的显示更准确,可作为法医鉴定的重要辅助检查手段。     

Postmortem non-invasive virtual autopsy: death by hanging in a car

A body was found behind a car with a noose tied around its neck, the other end of the rope tied to a tree. Apparently the man committed suicide by driving away with the noose tied around his neck and was dragged out of the car through the open hatchback. postmortem multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) indicated that the cause of death was cerebral hypoxia due to classic strangulation by hanging, and not due to a brainstem lesion because of a hang-man fracture as would be expected in such a dynamic situation. Furthermore, the MRI displayed intramuscular haemorrhage, bleeding into the clavicular insertions of the sternocleidomastoid muscles and subcutaneous neck tissue. We conclude that MSCT and MRI are useful instruments with an increased value compared with 2D radiographs to augment the external findings of bodies when an autopsy is refused. But further postmortem research and comparing validation is needed.     

人体胸廓骨骼三维有限元模型的构建及生物力学分析

目的建立完整的人体胸廓骨骼三维有限元模型,并探索力作用变化趋势。方法对尸体胸部进行多层螺旋CT(multislice computed tomography,MSCT)扫描,使用有限元建模软件根据CT图像数据对胸廓骨性结构进行三维重建并生成有限元模型,模拟胸廓右季肋部遭受速度为4、6与8m/s的钝性物体正面击打,分析胸廓受击打后的应力、应变分布情况。结果成功构建解剖学高仿真度的人体胸廓有限元模型,模型体网格平均质量0.7。生物力学分析结果显示胸廓受击打后发生局部弯曲及整体变形,应力与应变产生于初始打击部位肋骨,后沿肋骨向两侧传播,并于肋骨后侧及近胸骨处集中,6m/s与8m/s的打击速度可造成打击部位肋骨应变值超出相应强度极限,发生骨折。结论应用有限元建模分析软件能够建立符合真实情况的高质量的人体胸廓三维有限元模型,且模型可用于分析外力作用下胸廓骨性结构的应变趋势,为胸部损伤的致伤方式推断提供了新的途径和方法。     

Sexual Dimorphism of the Fetal Ilium: A 3D Geometric Morphometric Approach with Multislice Computed Tomography

Adult sexual dimorphism is well established. However, data regarding fetuses are sparse with contradictory results. Our study aimed to look for fetal sexual dimorphism. Multislice computed tomography (MSCT) examinations and three‐dimensional (3D) reconstructions were recorded on 93 fetal iliac bones aged between 21 and 40 weeks of amenorrhea (WA). The collection was divided into two age groups, with a cutoff at 30 WA. The 3D geometric morphometric analysis was based on outline analysis. We used elliptic Fourier analysis (EFA) because of the difficulty of landmark positioning. Step‐by‐step reconstructions allowed a better comprehension of the fine shape details. Principal component analysis (PCA) and linear discriminant analysis (LDA) were performed on the two age groups. Results did not show any difference between male and female shapes, in both age groups. We demonstrate the feasibility of outline analysis for immature shapes, but sexual dimorphism has not been established in our collection.     

多层螺旋CT冠状动脉钙化积分在评价冠心病猝死中的应用

目的通过运用多层螺旋CT（multi—slicespiralcomputedtomography,MSCT）冠状动脉钙化积分（coronaryarterycalciumscoring．CACS）的方法．评价其在冠心痛（coronaryarterydisease,CAD）猝死案例中的法医学应用价值,为虚拟解剖鉴定CAD猝死探索有效手段。方法收集9例进行法医学鉴定的心源性猝死案例．尸体解剖前均进行MSCT扫描。通过Agatston’s法对每例冠状动脉钙化程度进行定量分析,并计算CACS,钙化积分〉400作为存在CAD的评判标准,并与尸体解剖结果比较。结果经尸体解剖证实CAD猝死的9例案例中仅有2例钙化积分〉400,CACS对CAD的预测率仅为22．2％。MSCT检查与系统尸体解剖均发现CAD猝死案例中普遍存在不同程度肺水肿改变,冠状动脉左前降支较其他分支发生管腔狭窄的发病率高。结论运用MSCT并结合计算CACS可对CAD猝死案例中冠状动脉钙化明显的进行检测,而钙化不明显的需要辅以如尸体血管造影等其他技术。     

Application of the Iscan method to two- and three-dimensional imaging of the sternal end of the right fourth rib

Age determination is a major field of interest in physical and forensic anthropology. Among the different methods based on macroscopic skeletal study, the Iscan method, which analyzes the sternal end of the right fourth rib, is one of the most reliable. We applied the Iscan method to two- and three-dimensional multislice computed tomography (MSCT) reconstructions of the sternal end of the right fourth rib on 39 ribs. The intra-observer variability on MSCT reconstructions was good (gamma coefficient equal to 0.86; value of the Krippendorff's alpha reliability equal to 0.79); inter-observer variability on MSCT reconstructions was also good (gamma coefficient ranging from 0.82 to 0.88; value of the Krippendorff's alpha reliability ranging from 0.78 to 0.86). We demonstrated excellent agreement between the results of analysis of bone samples and those of the two- and three-dimensional images, in particular regarding bone projections, morphology of the pit and of its rim. The accuracy of age estimation did not significantly differ between the Iscan method applied to dry bones and the same method applied to MSCT images. Determination of the Krippendorff's alpha reliability coefficient for the inter-error method confirmed the agreement between phase estimations obtained with the two methods (ranging from 0.55 to 0.71). The real civil age was comprised in 21 cases out of 36 for assessment performed on dry bones and in 23 cases out of 36 on MSCT reconstructions, which represented 58.3% and 63.9%, respectively. Use of MSCT reconstructions in forensic anthropology offers many advantages: no bone preparation, no damage to bone material, and the possibility of application to living individuals.     

MSCT及图像后处理在鼻骨骨折法医鉴定中的应用

目的探讨多层螺旋CT(MSCT)及图像后处理在鼻骨骨折法医学鉴定中的应用价值。方法采用MSCT对134例被鉴定人进行薄层扫描并行多平面重建(MPR)和表面遮盖成像(SSD)。比较MSCT与常规X线诊断结果。结果线型骨折55(41.04%)例,粉碎型骨折46例(34.33%),凹陷型骨折27例(20.15%),未见骨折6例(4.48%)。X线平片及CR片漏、误诊48例(35.82%)。MSCT正确诊断133例(99.25%)。两者诊断结果存在显著差异(χ2=45.0816,P<0.001)。结论MSCT及后处理图像应作为鼻骨骨折法医鉴定的主要依据。     

多层螺旋CT检查在尸体颈椎损伤中的应用

对需要在尸体检验时进行颈椎多层螺旋CT(MSCT)检查的情形进行讨论,研究利用MSCT对疑有颈椎损伤的尸体进行颈椎检查的方法,并对一例疑似颈椎损伤尸体的颈椎提取后进行MSCT检查。发现对疑似有颈椎骨折尸体提取颈椎进行MSCT检查,可以快速精确地显示颈椎的细微骨折及骨折的空间分布,从而推断致伤方式。解决了传统尸检中费时费力,容易漏诊和误诊的问题。     

Post-mortem forensic neuroimaging: correlation of MSCT and MRI findings with autopsy results

Multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) are increasingly used for forensic purposes. Based on broad experience in clinical neuroimaging, post-mortem MSCT and MRI were performed in 57 forensic cases with the goal to evaluate the radiological methods concerning their usability for forensic head and brain examination. An experienced clinical radiologist evaluated the imaging data. The results were compared to the autopsy findings that served as the gold standard with regard to common forensic neurotrauma findings such as skull fractures, soft tissue lesions of the scalp, various forms of intracranial hemorrhage or signs of increased brain pressure. The sensitivity of the imaging methods ranged from 100% (e.g., heat-induced alterations, intracranial gas) to zero (e.g., mediobasal impression marks as a sign of increased brain pressure, plaques jaunes). The agreement between MRI and CT was 69%. The radiological methods prevalently failed in the detection of lesions smaller than 3mm of size, whereas they were generally satisfactory concerning the evaluation of intracranial hemorrhage. Due to its advanced 2D and 3D post-processing possibilities, CT in particular possessed certain advantages in comparison with autopsy with regard to forensic reconstruction. MRI showed forensically relevant findings not seen during autopsy in several cases. The partly limited sensitivity of imaging that was observed in this retrospective study was based on several factors: besides general technical limitations it became apparent that clinical radiologists require a sound basic forensic background in order to detect specific signs. Focused teaching sessions will be essential to improve the outcome in future examinations. On the other hand, the autopsy protocols should be further standardized to allow an exact comparison of imaging and autopsy data. In consideration of these facts, MRI and CT have the power to play an important role in future forensic neuropathological examination.     

Virtual anthropology and forensic identification: report of one case

A charred body was found after a fire in a house in a mountainous region of France. The body was severely burned and was not formally identified as the owner of the house. Autopsy was carried out to seek vital reactions and/or traumatic lesions and to identify the corpse. Before bone preparation and after autopsy, multislice computed tomography (MSCT) was performed in order to assess the potential of the technique for radiological anthropological bone identification. The challenge was to determine as accurately as possible the sex, age, ante-mortem stature and ethnic of the victim using both MSCT and conventional bone study. The results of the two techniques were compared. MSCT provided an answer to all the questions, whereas bone study did not. To the best of our knowledge, this case is the first to use MSCT for forensic anthropological study and illustrates the potential contribution of this technique in this field.