大鼠实验性脑梗死早期CT值和GFAP表达变化的研究

目的探讨大鼠24h内实验性脑梗死CT值及脑内胶质纤维酸性蛋白(GFAP)的表达变化,以间接推测脑梗死的发生时间。方法参照Longa线栓法建立大鼠大脑中动脉栓塞脑梗死模型,在不同时相点进行头颅CT扫描,测量右侧脑梗死和左侧未梗死区脑组织的CT值并求出两侧的差值。同时用免疫组化检测脑内GFAP的表达变化。结果6h组大鼠CT平扫均有明确的脑梗死灶,梗死与非梗死两侧脑组织CT值的差值与梗死时间呈直线正相关,GFAP表达与梗死时间也有一定的相关性。结论血管栓塞引起的脑梗死最早于梗死发生后6h可以诊断,并可通过脑梗死与非梗死两侧CT值的差值计算及GFAP表达变化来推测脑梗死发生的时间。     

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。     

骨折法医鉴定中常规X线与CT漏诊、误诊的技术因素分析

目的探讨X线平片和常规CT检查技术对骨折漏、误诊的影响。方法对366例已接受普通X线或常规CT检查的骨折法医鉴定者行MSCT扫描并行对照性研究。结果骨折法医鉴定中普通X线、常规CT漏、误诊率分别为40.83%和29.73%,存在显著统计学差异(x2=4.69,P<0.05)。二者漏、误诊病例中与技术因素相关者分别占66.29%和88.63%,亦存在显著统计学差异(x2=7.58,P<0.01)。结论普通X线与常规CT的设备和技术缺陷与失误是造成漏、误诊的重要因素。     

Age Estimation of Adult Living Donor by Pubic MSCT Three-dimensional ReconstructionCSCD

Objective: To establish a method for the age estimation of adult living donor based on pubic MSCT three-dimensional reconstruction and verify its accuracy and reliability. Methods: The volume rendering (VR)image data of pubic symphysis surface were collected from 300 volunteers aged over 17 years old. According to different age groups, the age estimation of these volunteers was performed by the method and formula of pubic symphysis surface. Results: In the 300 volunteers, the difference between biological age and actual age was <1 year in 117 cases, >1-2 years in 178 cases, >2 years in 5 cases. Conclusion: MSCT three-dimensional reconstruction technology of pubic symphysis surface can be used to estimate the age of adult living donor, which can provide a high accurate and reliable result. © 2018 by the Editorial Department of Journal of Forensic Medicine.     

大鼠实验性脑梗死后早期CT表现的法医学研究

目的探讨24h内脑梗死CT值的变化与梗死时间的关系以及CT表现。方法采用线栓法制作大鼠大脑中动脉梗死模型,于梗死后2、3、4、6、8、12、24h进行头颅CT冠状位扫描。观察CT图像,测量两侧大脑半球对称部位的CT值,并求出两者的差值。结果线栓法大鼠脑梗死后最早于3h肉眼即可辨别梗死灶,其患侧CT值与健侧有显著性差异,且脑梗死健、患侧CT值的差值与时间呈直线正相关。结论血管栓塞引起的脑梗死最早于梗死发生后3h即可诊断,并可通过脑梗死两侧CT值的差值的计算来推断脑梗死发生的时间。     

The application of CT for 3D visualization of concealed bodies

In forensic radiology, computed tomography (CT) is often used as a medical imaging technique to identify the cause and manner of death of deceased victims of a possible crime. In this study, medical imaging is used to examine concealed bodies and packaging materials. Medical imaging techniques, mainly CT scan, were used to scan packaged or concealed bodies inside containers to identify clues and evidence indicating whether a crime might have been committed. Also, scene integrity and scene safety along with a systematic search for relevant evidentiary items value were considered.Eighteen concealed bodies that had been assessed using medical imaging techniques between 2010 and 2018 at the request of the Dutch National Police were selected. The file records of each case contained imaging data, a photographic record of the unpacking procedure, a list of all items and traces found in the package, and the forensic pathology report. The images were assessed with respect to the different aspects of the case and through a systematic approach.The packages included adult males, adult females, newborn infants, and animals. All human cases were related to criminal offences. In nine adult cases, evidence of a possible violent death could be determined using CT imaging. The cause of death in newborn infants, however, could not be determined. In cases of dismemberment, the completeness of the body could be determined by CT imaging, and the cutting surfaces of bones could be matched on CT images. Regarding scene safety and integrity, in this study all relevant macroscopic items were detected on the CT images.The CT-scans were supplemented with fiduciary markers to better map CT data with the real objects. This information in combination with 2D and 3D images provided the forensic investigator with information on how to unwrap the package layer by layer and help determine different types of packaging materials. Different textiles could not always be identified. The orientation of the body within the packages was provided in all cases, and advice could be given on the optimal approach to access the contents. The overall detection rate of items was 78%.This is one of the first studies to illustrate the contribution of medical imaging, specifically CT scan, to the analysis of concealed bodies and packaging materials prior to unpacking. This demonstrates its contribution to a systematic approach of the investigation by ensuring the safety and health of the investigator while documenting and maintaining the integrity of the crime scene. Imaging also provides information that can be helpful to determine whether a crime might have been committed and reducing the risk of damaging a concealed body. Medical imaging also provides the forensic investigator with information to draw up a workplan prior to unpacking, minimising loss of evidence and determining whether different forensic specialists (e.g., digital or DNA) are needed. It is therefore strongly recommended to use medical imaging, especially CT scanning, before opening a package containing a concealed body.