离体心脏冠状动脉造影术及其法医学应用

目的应用冠状动脉造影技术对离体心脏进行检查,以便更准确地发现冠状动脉病变的位置、性质和程度,提高综合评价心血管疾病的能力。方法提取10例不同死因的新鲜离体心脏,用指环注射器对离体心脏加压注射硫酸钡造影剂,在Xper FD20血管造影机下显影,获取图片及影像资料,应用造影机附带软件对所获得的影像资料进行三维成像处理。取冠状动脉组织HE染色,镜下观察,并与造影结果对比。结果 10例检材经造影获得的影像学资料,其中8例冠状动脉主支及各分支未发现狭窄,2例检材发现存在Ⅲ级、Ⅳ级冠状动脉狭窄。与冠状动脉组织HE染色结果一致,二者相互印证。结论离体冠状动脉造影技术对于冠状动脉狭窄准确分级、血管畸形及微小病变的检验有其独特的优越性,可为尸体检验病理取材时微小病变的定位提供参考,为鉴定意见提供依据。     

冠心病合并冠状动脉血栓猝死的法医病理学特征

目的探讨冠心病合并冠状动脉血栓形成导致猝死的法医学特征。方法收集96例因冠心病而猝死的案例,并将其分为血栓形成组与无血栓形成组,对发病时间、诱因、病理特征等方面进行分析。结果两组都以男性为主,在季节和时间节律分布、诱因构成上差异无统计学意义,但血栓形成组中年龄〈40岁发病率更高;血栓形成组的心脏质量和冠脉狭窄程度低于无血栓形成组,而两组冠脉粥样硬化累及的支数（≥2）、累及长度及合并心梗等指标差异均无统计学意义,但血栓形成组有低于无血栓形成组的趋势。结论两组人群都以男性为主且发病诱因、冠脉病变部位及致死机制相似,但血栓形成组的发病年龄较轻,心脏的病变程度较低,法医学解剖中当认真鉴别。     

Forensic Radiology Pitfalls: CT Imaging in Gunshot Wounds of the Head

Computed tomography (CT) imaging is increasingly used in emergency departments and trauma services and is being offered as a supplemental tool with autopsy in coroner's and medical examiner's offices throughout the United States. The availability of CT images in lieu of traditional X‐rays for medicolegal autopsies may lead to misinterpretation of images for forensic pathologists who are not familiar with these types of images. Forensic pathologists must become familiar with CT imaging, the basis of CT image formation and how to interpret CT images appropriately. We highlight potential pitfalls of CT image interpretation through two cases of fatal gunshot wounds of the head. Antemortem CT imaging available at the time of autopsy led to discrepancy between the initial image findings and the autopsy due to inexperienced manipulation of the images. With appropriate understanding of CT image interpretation and manipulation, forensic personnel should be able to avoid most sources of misinterpretation.     

The effects of the (fentanyl-fueled) drug overdose epidemic on medicolegal death investigation in the United States

The evolving opioid epidemic in the United States, fueled by illicit fentanyl, has greatly increased deaths from illicit drug use. These nonnatural deaths require formal death investigation. The National Association of Medical Examiners states in its Forensic Autopsy Performance Standards that autopsy remains a necessary component for proper investigation of suspected acute overdose deaths. If a death investigation office lacks adequate resources to investigate all deaths under its jurisdiction while meeting expected standards, then that office may be forced to consider altering its protocols for investigation by changing the types of deaths investigated or the extent of its investigations. Drug death investigations take longer to complete because novel illicit drugs and mixtures of drugs complicate toxicological analyses, prolonging a family's wait for completion of a death certificate and autopsy report. Public health agencies must also wait for results, but some agencies have developed mechanisms for rapid notification of preliminary results to allow timely deployment of public health resources. The increased deaths have strained the resources of medicolegal death investigation systems throughout the United States. Given the significant workforce shortage of forensic pathologists, newly trained forensic pathologists are too few to meet the demand. Nevertheless, forensic pathologists (and all pathologists) must make time to present their work and themselves to medical students and pathology trainees to encourage an understanding of the importance of quality medicolegal death investigation and autopsy pathology and to provide a model that can encourage interest in a career in forensic pathology.     

Concordance Rate for the Identification of Distant Entrance Gunshot Wounds of the Back by Experienced Forensic Pathologists Examining Only Images of Autopsies

The images of 66 gunshot entrance wounds with a defect on the back, a bullet in the body, hemorrhage along the wound track, and logical certainty that it was an entrance wound were collected from the files of a moderately busy medical examiner's office. Participants numbering 22 board‐certified forensic pathologists viewed a single digital archival image of each of the 66 entrance wounds randomly mixed with 74 presumptive exit wounds to determine whether they were entrance or exit wounds. The concordance rate for correctly identifying the 66 logically known entrance wounds was 82.8% with a range from 58% to 97%. This pilot study was conducted to provide an evidence‐based approach to the interpretation of the direction of gunshot wounds by reviewing pathologists with access only to archival photographs, and it is not a measure of the accuracy to distinguish entrance from exit wounds when given all of the circumstances.     

A Comparative Assessment of the Chen et al. and Suchey‐Brooks Pubic Aging Methods on a North American Sample, ,

Accurately estimating the age‐at‐death of adult human skeletons is fundamental in forensic anthropology. This study evaluates the accuracy of two pubic bone age estimation methods—Chen et al. and Suchey‐Brooks. Specimens were obtained from a known collection of modern pubic bones curated at the Maricopa County Forensic Science Center in Phoenix, Arizona. A sample of 296 left male pubic bones of European ancestry was statistically evaluated via bias, absolute mean error, and intra‐ and inter‐observer error. Results indicate that the two methods are similar; the Suchey‐Brooks method is the most accurate for aging young adults (error c. 7 years), while the Revised Chen et al. method is most accurate for aging middle‐age adults (error c. 6 years). Thus, the Chen et al. method is an important contribution to forensic anthropology for aging older adult skeletal remains. There are, however, some limitations such as subjectivity and the intricate scoring system of Chen et al. method.     

Comparative Analysis of Insect Succession Data from Victoria (Australia) Using Summary Statistics versus Preceding Mean Ambient Temperature Models

Minimum postmortem interval (mPMI) can be estimated with preceding mean ambient temperature models that predict carrion taxon pre‐appearance interval. But accuracy has not been compared with using summary statistics (mean ± SD of taxon arrival/departure day, range, 95% CI). This study collected succession data from ten experimental and five control (infrequently sampled) pig carcasses over two summers (n = 2 experimental, n = 1 control per placement date). Linear and exponential preceding mean ambient temperature models for appearance and departure times were constructed for 17 taxa/developmental stages. There was minimal difference in linear or exponential model success, although arrival models were more often significant: 65% of linear arrival (r² = 0.09–0.79) and exponential arrival models (r² = 0.05–81.0) were significant, and 35% of linear departure (r² = 0.0–0.71) and exponential departure models (r² = 0.0–0.72) were significant. Performance of models and summary statistics for estimating mPMI was compared in two forensic cases. Only summary statistics produced accurate mPMI estimates.     

A Pilot Study Comparing Postmortem and Antemortem CT for the Identification of Unknowns: Could a Forensic Pathologist Do It?

Forensic pathologists are commonly tasked with identifying human remains. Although DNA analysis remains the gold standard in identification, time and cost make it particularly prohibitive. Radiological examination, more specifically analog imaging, is more cost-effective and has been widely used in the medical examiner setting as a means of identification. In the United States, CT imaging is a fairly new imaging modality in the forensic setting, but in more recent years, offices are acquiring CT scans or collaborating with local hospitals to utilize the technology. To broaden the spectrum of potential identifying characteristics, we collected 20 cases with antemortem and postmortem CT images. The results were qualitatively assessed by a forensic pathologist and a nonmedically trained intern, and all cases were correctly identified. This study demonstrates that identification of human remains using visual comparison could be performed with ease by a forensic pathologist with limited CT experience.     

Ossification of laryngeal structures as indicators of age

As the role of forensic anthropologists expands to the medical examiner setting, their expertise is being applied beyond the traditional dry skeletal material. In such scenarios radiographic techniques can be applied when maceration is not appropriate. This study explores the use of radiographic analysis of laryngeal structures for age-at-death determination. Isolated human laryngeal structures (n = 104) from individuals between the ages of 15 and 89 were removed at autopsy and radiographically examined. The cricoid and individual regions of the thyroid cartilage were scored according to degree of ossification, and the relationship between age and degree of ossification statistically examined. A previously published study on age-determination from thyroid ossification by Cerny was assessed for accuracy. The results of the study indicate that although a consistent sequence in the ossification of laryngeal structures exists, variations in timing does not permit narrow age range estimates. Consequently the method presented by Cerny is inaccurate and should not be used in the forensic setting.     

Testing Anatomical Methods for Stature Estimation on Individuals from the W. M. Bass Donated Skeletal Collection

Abstract:  This study compared eight versions of the anatomical method for stature estimation on a white male sample ( n  = 34) from the W. M. Bass Donated Skeletal Collection. The aim was to evaluate errors in the estimates and to discuss how useful the methods are in forensic context. The average error estimating living stature was less than 1 cm for six of the methods. The correlations between the estimates were high ( r  = 0.982–0.999). In practice, differences between the versions as well as those between long bone-based equations and anatomical methods were small. Anatomical method is nevertheless more accurate than long bone regressions when individuals with atypical body proportions are examined.     

Age Estimation Based on Pulp Cavity to Tooth Volume Ratio Using Postmortem Computed Tomography Images

Pulp cavity size is known to decrease with age and can therefore serve as an indicator for age estimation. Here, we evaluated whether reconstructed images of multidetector‐row computed tomography (MDCT) acquired before forensic autopsy are useful for estimating age at death. Images of 136 mandibular first premolars obtained from bodies of known age at death were analyzed, and the volume of the regions corresponding to pulp cavity and that of the whole tooth were determined using a voxel counting function. The pulp cavity was clearly distinguishable from dental hard tissue on the reconstructed images when using a cutoff value of 1400 Hounsfield units. Regression analysis adjusted for sex showed that estimated age correlated significantly with the pulp cavity to tooth volume ratio (r = 0.76). MDCT is gaining more widespread use in forensic medicine, and analyzing dental images to obtain parameters for age prediction is a practical approach for postmortem identification.     

Proficiency Testing as a Basis for Estimating Uncertainty of Measurement: Application to Forensic Alcohol and Toxicology Quantitations

Abstract: While forensic laboratories will soon be required to estimate uncertainties of measurement for those quantitations reported to the end users of the information, the procedures for estimating this have been little discussed in the forensic literature. This article illustrates how proficiency test results provide the basis for estimating uncertainties in three instances: (i) For breath alcohol analyzers the interlaboratory precision is taken as a direct measure of uncertainty. This approach applies when the number of proficiency tests is small. (ii) For blood alcohol, the uncertainty is calculated from the differences between the laboratory’s proficiency testing results and the mean quantitations determined by the participants; this approach applies when the laboratory has participated in a large number of tests. (iii) For toxicology, either of these approaches is useful for estimating comparability between laboratories, but not for estimating absolute accuracy. It is seen that data from proficiency tests enable estimates of uncertainty that are empirical, simple, thorough, and applicable to a wide range of concentrations.     

Measurement of Postmortem Pupil Size: A New Method with Excellent Reliability and Its Application to Pupil Changes in the Early Postmortem Period

Measurement of postmortem pupil width is a potential component of death time estimation. However, no standardized measurement method has been described. We analyzed a total of 71 digital images for pupil–iris ratio using the software ImageJ. Images were analyzed three times by four different examiners. In addition, serial images from 10 cases were taken between 2 and 50 h postmortem to detect spontaneous pupil changes. Intra‐ and inter‐rater reliability of the method was excellent (ICC > 0.95). The method is observer independent and yields consistent results, and images can be digitally stored and re‐evaluated. The method seems highly eligible for forensic and scientific purposes. While statistical analysis of spontaneous pupil changes revealed a significant polynomial of quartic degree for postmortem time (p = 0.001), an obvious pattern was not detected. These results do not indicate suitability of spontaneous pupil changes for forensic death time estimation, as formerly suggested.     

Comparing the Scoring of Human Decomposition from Digital Images to Scoring Using On‐site Observations

When in forensic casework or empirical research in‐person assessment of human decomposition is not possible, the sensible substitution is color photographic images. To date, no research has confirmed the utility of color photographic images as a proxy for in situ observation of the level of decomposition. Sixteen observers scored photographs of 13 human cadavers in varying decomposition stages (PMI 2–186 days) using the Total Body Score system (total n = 929 observations). The on‐site TBS was compared with recorded observations from digital color images using a paired samples t‐test. The average difference between on‐site and photographic observations was ?0.20 (t = ?1.679, df = 928, p = 0.094). Individually, only two observers, both students with <1 year of experience, demonstrated TBS statistically significantly different than the on‐site value, suggesting that with experience, observations of human decomposition based on digital images can be substituted for assessments based on observation of the corpse in situ , when necessary.     

Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series,

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner’s office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re-evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head–neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar’s test. We included 60 males and 20 females (median age 31 years, range 3–73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head–neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs.     

Radiographic Identification Using Midline Medical Sternotomy Wires,

Forensic anthropologists are regularly asked to assist with the identification of unknown individuals using comparative medical radiography. This study addressed the use of midline medical sternotomy wires as a means for personal identification. Antemortem and postmortem radiographic comparisons were completed by 46 professional forensic anthropologists and anthropology graduate students familiar with comparative medical radiography as a technique for assessing identification. Participants were asked to make five radiographic matches from a pool of 20 radiographs. Participants also completed an anonymous survey detailing their education level and experience making radiographic comparisons. Participants were 99.5% accurate in matching the radiographs. Sensitivity was 98.7%, and specificity was 99.7%. Logistic regression analysis found no statistically significant differences in the participants' ability to make a correct match. As the high accuracy rates indicate, the shape, size, and various characteristics of the sternotomy wires are individualizing and can confidently be used when assisting with personal identification cases.     

Identification Using Frontal Sinus by Three‐Dimensional Reconstruction from Computed Tomography*

Abstract: Radiographs and computed tomography (CT) images have been increasingly applied and accepted in forensic sciences. Along with radiographs and CT images, the frontal sinus is often used for the individual identification because of its unique and unchangeable characteristics. The purpose of this study is to define the usefulness of three‐dimensional (3‐D) images of the frontal sinus for identification. CT images from 119 Korean cadavers were built up for 3‐D reconstruction and surveyed with 15 measurements. The total volume of the sinus, some nonmetric characteristics, and the bilateral asymmetry index in men differed significantly from those in women (p < 0.05). The digit codes, six sections and 10‐digit number, were almost able to accurately identify individuals (98%). This study showed a statistical difference between the sexes and classified the fused and prominent middle sinuses for the first time. This proposed method for identification is more accurate than those used in other studies.     

Forensic pathology--the hidden specialty: A survey of forensic pathology training available to medical students and residents

It is no wonder that some people refer to forensic pathology as the "hidden specialty." This paper shows evidence that the only exposure given to most medical students is a brief, all-too-explicit demonstration ("horror show") of interesting cases that can only attract the bizarre of mind into the field. It is further pointed out that even residents in pathology receive scanty, if any, formal training in most medical school residency programs, in spite of the fact that two thirds of the medical schools responding have one or more forensic pathologists on their faculty. The obvious answer is a change in the curriculum if this increasingly important subspecialty is to be saved.     

Strengths,Limitations, and Recommendations for Instrumental Color Measurement in Forensic Soil Characterization

Color determination of soil evidence is often done by visual comparison to soil color charts. A handheld spectrophotometer was tested with representative materials for its suitability for forensic soil characterization. Instrumental colorimetry provides accurate colorimetry with ~10-fold better precision than a soil color chart. The minimum sample size for accurate color determination was between 0.02 and 0.04 mg of fine soil for the specific instrument tested. Reporting colors in the L*a*b* space permits quantification of ΔE₀₀, a measure of perceptible color difference, could enable objective quantification of small color differences and thresholds for forensic soil comparisons. A ΔE₀₀ greater than ~ 3.5 to 6 likely indicates disparate soil sources in a forensic comparison, in the absence of confounding factors like sample alteration. Despite the superior precision of instrumental colorimetry, this approach is inappropriate for samples which are mottled at an inseparable scale, attached to a substrate, or too small for instrumental measurement.     

The forensic or medicolegal autopsy. Friend or foe?

The major issue in questioning the performance of general pathologists doing medicolegal or forensic autopsies is that they are very often without a firm basis for performing this task. With minimal training in medical school and minimal exposure during their residency, practicing general pathologists, although expected or even forced to do these cases, may face criticism after their performance in a case. The necessity for teaching forensic medicine and pathology in medical schools is obvious, and the necessity of there being more forensic pathology exposure in residency training programs in the United States and overseas is also obvious. Medical educators are responsible for all phases of medicine being taught to medical undergraduates and graduates and must be pressured to support the practice of all kinds of medicine in American communities, including legal or forensic medicine, in those cases in which questions arise that lead to the performance of postmortem examination.