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Rapid and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dead bodies is essential to prevent infection among those working with dead bodies. This study focused on the Smart Amplification (SmartAmp) method, which has a short examination time (approximately an hour), is simple to perform, and demonstrates high specificity and sensitivity. This method has already been used for clinical specimens; however, its effectiveness in dead bodies has not been reported. This study examined the SmartAmp method using 11 autopsies or postmortem needle biopsies performed from January to May, 2021 (of these, five cases tested positive for SARS-CoV-2 by quantitative real-time polymerase chain reaction (qRT-PCR) and six cases tested negative). Swab samples were collected from the nasopharynx, oropharynx, or anus and the SmartAmp and qRT-PCR results were compared. For the nasopharynx and oropharynx samples, the same results were obtained for both methods in all cases; however, for the anal swabs, there was one case that was positive according to qRT-PCR but negative according to the SmartAmp method. The SmartAmp method may therefore be less sensitive than qRT-PCR and results may differ in specimens with a low viral load, such as anal swabs. However, in the nasopharynx and oropharynx specimens, which are normally used for testing, the results were the same using each method, suggesting that the SmartAmp method is useful in dead bodies. In the future, the SmartAmp method may be applied not only during autopsies, but also in various situations where dead bodies are handled.

Analysis of ions in sphenoidal fluid can be a useful index for the diagnosis of drowning. We evaluated the reference ranges of non-drowning cases using statistical methods and three indices: sodium ion (Na+), summation of sodium and potassium ions (SUMNa+K), and summation of sodium, potassium and chloride ions (SUMNa+K+Cl). The reference ranges were 96≤Na+

To clarify the differences between postmortem CT (PMCT) and autopsy findings in the postmortem detection of cervical spine injuries (CSIs).Our department's forensic pathology database was searched for CSI cases. In each case, the autopsy data and radiologists' interpretations were reviewed for the presence of bone fractures and intervertebral injuries.The study included 42 cases. For both bone fractures and intervertebral injuries, no substantial concordance between PMCT and autopsy findings was observed (McNemar's test: p0.001 and p0.001, respectively). Regarding bone fractures, more injuries were detected with CT than with autopsy (CT: 74, autopsy: 23). The percentage of CT-detected fractures that were missed at autopsy (77.0%, 57/74) was higher than the percentage of autopsy-detected fractures missed with CT (26.1%, 6/23). Regarding intervertebral injuries, fewer injuries were detected with CT than with autopsy (CT: 40, autopsy: 80). The percentage of CT-detected injuries that were missed at autopsy (35.0%, 14/40) was lower than the percentage of autopsy-detected injuries that were missed with CT (67.5%, 54/80).A substantial number of CSIs were detected by either PMCT or autopsy alone. Accurate evaluation for CSI requires the use of both methods.

This study examined the mechanical properties of the adult sagittal suture compared with surrounding parietal bones using bending tests and investigated the association between the mechanical properties of the suture and age. We used the heads of 116 Japanese cadavers (76 male cadavers and 40 female cadavers) of known age and sex. A total of 1160 cranial samples, 10 from each skull, were collected. The samples were imaged using multidetector computed tomography, and the sample thickness at the center of each sample (ST) was measured. The failure stress of each sample (FS) was measured by a bending test, and the ratio of failure stress to the square of sample thickness (FS/ST 2 ) was calculated. Statistical analyses revealed that the FS and FS/ST 2 values were significantly lower at all suture sites than at all bone sites regardless of sex. There were not significant but slight positive correlations between age and FS and FS/ST 2 values at any suture site in male samples. In female samples, age had significant positive correlations with FS and FS/ST 2 values at the middle suture sites, whereas there were not significant but slight positive correlations between age and FS and FS/ST 2 values at the edges of the suture. Statistical analyses also demonstrated that FS and FS/ST 2 values were significantly greater in male samples than in female samples at the middle suture sites. These findings suggest that the bending strength of the adult sagittal suture is significantly lower than that of surrounding parietal bones. Therefore, avoiding direct impact on cranial sutures may be important for preventing skull fractures and severe complications that can cause death. The results of this study also revealed that the bending strength of the middle sagittal suture significantly increases with age in only female samples, whereas the bending strength is significantly higher in male samples than in female samples at the middle suture sites, indicating the possibility of sex difference in the bony interdigitation of the sutures during childhood.

Accurate sex estimation from unknown human remains is crucial as an integral and foremost step toward individual identification. The aims of this study were to assess sexual dimorphism of the clavicle and develop discriminant equations for sex estimation in a modern adult Japanese population based on clavicular measurements using three-dimensional (3D) computed tomographic (CT) images. A total of 300 cadavers (150 males, 150 females) of known age and sex that underwent postmortem CT and subsequent forensic autopsy were obtained. Four measurements were performed using 3D CT reconstructed images that extracted only bones based on the CT values, as follows: the linear distances between the medial superior margins of the left and right sternal facets to the lateral points of the left and right acromial ends, and the linear distances between the medial superior margins of the left and right sternal facets to the tips of the left and right conoid tubercles. The mean values of all measurements were significantly greater for male subjects than female subjects. Univariate discriminant function analysis (DFA) provided correct sex prediction rates of 88.3-92.2%. Stepwise DFA for the left and right clavicles yielded sex classification accuracy rates of 92.2% and 91.0%, respectively. In conclusion, clavicular measurements using 3D CT images of a contemporary Japanese population may be useful for sex estimation in forensic contexts.

We aimed to reproduce the anthropometrical measurements of femoral dimensions using multi-planar reconstruction (MPR) computed tomography (CT); to assess the feasibility of sex estimation using femoral measurements through this approach, and to establish the corresponding sex estimation thresholds in the modern Japanese population. We used data on 224 cadavers (116 male and 108 female) that were subjected to postmortem CT and subsequent forensic autopsy at our department between October 2009 and July 2016. Four femoral measurements were obtained. Receiver operating characteristic (ROC) curve analysis was performed to test the overall ability of the variables in sex estimation, while the accuracy of the sex estimation was measured by the area under the ROC curve (AUC). The femoral bicondylar breadth showed the largest AUC values (left; 0.973, right; 0.974), followed by the maximum head diameter (left; 0.951, right; 0.955), and maximum femoral length (left; 0.885, right; 0.887). To the best of our knowledge, this is the first report to assess sex estimation based on femoral measurements, using MPR CT images.

The aims of this study was to assess the correlation between stature and clavicular measurements in a contemporary Japanese population using three-dimensional (3D) computed tomographic (CT) images, and to establish regression equations for predicting stature. A total of 249 cadavers (131 males, 118 females) underwent postmortem CT scanning and subsequent forensic autopsy between October 2011 and May 2016 in our department. Four clavicular variables (linear distances between the superior margins of the left and right sternal facets to the anterior points of the left and right acromial ends and between the superior margins of the left and right sternal facets to the left and right conoid tubercles) were measured using 3D CT reconstructed images that extracted only bone data. The correlations between stature and each of the clavicular measurements were assessed with Pearson product–moment correlation coefficients. These clavicular measurements correlated significantly with stature in both sexes. The lowest standard error of estimation value in all, male, and female subjects was 3.62 cm ( r 2 = 0.836), 3.55 cm ( r 2 = 0.566), and 3.43 cm ( r 2 = 0.663), respectively. In conclusion, clavicular measurements obtained from 3D CT images may be useful for stature estimation of Japanese individuals, particularly in cases where better predictors, such as long bones, are not available.

Accurate sex estimation is important in forensic investigation to determine the identity of unknown individuals. The aim of this study was to investigate the accuracy of sex assessment based on measurements of the second cervical vertebra (C2) using computed tomographic (CT) images in a Japanese population and to develop discriminant function formulae. The data were collected from 224 Japanese cadavers (112 male subjects, 112 female subjects) on which postmortem CT scanning and subsequent forensic autopsy were performed. Nine CT measurements of the C2 were performed for CT images of each subject. The measurements were assessed using descriptive statistics and discriminant function analyses (DFA). All of the measurements demonstrated significant sexual dimorphism. Multiple DFA with stepwise variable selection resulted in multivariable models; a five-variable model reached an accuracy rate of 92.9%. Our results suggest that metric analysis based on CT images of the C2 can accurately determine the sex from the human skeletal remains in a contemporary Japanese population and may be useful for sex estimation in forensic anthropology.

Accurate sex estimation based on measurements of dimorphic dimensions in human unknown remains is important as the first step toward making individual identification. The purpose of this study was to assess the sexual dimorphism of the scapula and to quantify the accuracy of sex estimation in a contemporary Japanese forensic sample using scapular measurements based on three-dimensional (3D) computed tomographic (CT) images. A total of 218 cadavers (109 males, 109 females) that underwent postmortem CT and subsequent forensic autopsy were used. Ten scapular measurements were performed on 3D CT reconstructed images that extracted only bone data, and were analyzed using descriptive statistics and discriminant function analyses (DFA). All measurements were dimorphic in terms of sex differences. Univariate DFA provided sex classification accuracy rates of 75.7–91.3%. Stepwise DFA yielded sex prediction accuracy rates of 93.1–94.5%. In conclusion, the scapular measurements using 3D CT images of a contemporary Japanese population may be useful for the estimation of skeletal sex in the field of forensic anthropology.

Sex estimation of decomposed or skeletal remains is clearly important in forensic contexts. Recently, contemporary population-specific data has been obtained using multidetector computed tomography (MDCT) scanning. The main purpose of this study was to investigate skeletal pelvic dimorphism in a contemporary Japanese forensic sample and to quantify the accuracy of sex estimation using various pelvic measurements obtained from three-dimensional (3D) CT images. This study used a total of 208 cadavers (104 males, 104 females) of which postmortem CT scanning and subsequent forensic autopsy were conducted between December 2011 and August 2014. Eleven measurements of each pelvis were obtained from 3D CT reconstructed images that extracted only bone data. The measurements were analyzed using descriptive statistics and discriminant function analyses. All except one measurement were dimorphic in terms of sex differences. Univariate discriminant function analyses using these measurements provided sex classification accuracy rates of 62.0-98.1%. The subpubic angle was found to contribute most significantly to accurate sex estimation. Multivariate discriminant functions yielded sex prediction accuracy rates of 63.9-98.1%. In conclusion, the pelvic measurements obtained from 3D CT images of a contemporary Japanese population successfully demonstrated sexual dimorphism and may be useful for the estimation of skeletal sex in the field of forensic anthropology.

The aim of this study was to assess the mechanical properties and thickness of adult frontal and parietal bones. The heads of 114 Japanese cadavers (78 male cadavers and 36 female cadavers) of known age and sex were used. A total of 912 cranial samples, 8 from each skull, were collected. Samples were imaged using multidetector computed tomography to measure sample thickness. The fracture load of each sample was measured using a bending test with calculation of flexural strength. Statistical analyses demonstrated no significant bilateral difference in either the mechanical properties or thickness of frontal or parietal bones. The mechanical properties and thicknesses of frontal bones were significantly greater than those of parietal bones regardless of sex. Therefore, the skull may have a great ability to resist frontal impacts compared with parietal impacts. In female samples, parietal bones were found to have a more uniform structure when compared with male samples. Male parietal bones were found to be thicker at medial sites than at lateral sites. This study also revealed parietal bones at lateral sites in female samples were thicker than in male samples. No strong association was observed between age and flexural strength of frontal or parietal bones. However, the fracture load was negatively correlated with age most likely due to the reduction of thickness.

We present an autopsy case of sudden death due to coronary artery dissection associated with fibromuscular dysplasia (FMD) in a young female patient. Postmortem selective coronary artery computed tomography (CT) angiography revealed dissections of the left anterior descending and left circumflex arteries. These findings were confirmed by subsequent autopsy. Histopathological examination revealed coronary artery FMD, which is considered a risk factor for dissection. To the best of our knowledge, this is the first postmortem radiology-pathology correlation of coronary artery dissection associated with FMD.

We report a fatal case of suspected Clostridium (Cl.) perfringens septicemia in a previously healthy woman in her eighties. At first, she presented at the hospital complaining of upper abdominal discomfort and vomiting, and was discharged the next day after ruling out any fatal conditions. However, her condition deteriorated approximately 10h after discharge and she died shortly after. The postmortem computed tomography (PMCT) performed 29h postmortem revealed an excessive systemic gas accumulation compared with the postmortem external appearance and time elapsed since her death, which suggested the presence of a gas-forming infection. Histopathological examination showed diffuse proliferation of Gram-positive bacilli in almost all the organ tissues, especially in blood vessels. Along with these findings, hyperthermia 3h postmortem, and severe anemia and thrombocytopenia without an obvious site of hemorrhage suggested hemolysis due to Cl. perfringens septicemia. These findings suggested the diagnosis before performing the conventional autopsy. To the best of our knowledge, this is the first case report to describe PMCT findings of gas-forming infection and septicemia in contrast with the external appearance and histopathological findings in a medico-legal autopsy setting.

Stature estimation using a skeleton is important for the medicolegal investigation of unidentified human remains. The aims of this study were to identify a correlation between stature and measurements of the sternal medullary cavity using multidetector computed tomography (MDCT) and derive regression equations for stature estimation in the Japanese population. Measurements were conducted on 215 Japanese subjects (107 males, 108 females) who underwent postmortem computed tomography with subsequent forensic autopsy between May 2012 and January 2014. For assessment, MDCT cross-sections through the mid-point of the first costal facets were chosen. The length of a rising diagonal stroke from the bottom left to the top right of the sternal medullary cavity (RS) and the length of a falling diagonal stroke from top left to bottom right of the sternal medullary cavity (FS) were measured. Statistical analyses indicated that both RS and FS were positively correlated with stature regardless of sex. The correlations were stronger for males than for females. The correlation coefficients for RS were higher than those for FS, and standard errors of estimation calculated by regression analysis using RS were lower than those using FS regardless of sex. Measurement of the sternal medullary cavity using MDCT images may be a potentially useful tool for stature estimation, particularly in cases where better predictors such as long bones are not available.

Traumatic common carotid artery dissection is very rare, and although it is associated with mild symptoms, it can sometimes be fatal. Therefore, careful examination of common carotid artery dissection and additional pathological examination as appropriate are important during the autopsy of traumatic death patients. A 60-year-old previously healthy drunken woman was run over. She had remained unconscious shortly after the accident, and 15 h later, emerging bilateral cerebral infarction was confirmed using brain computed tomography. Despite conservative management, she died 4 days after the injury due to multiple chest traumas and broad cerebral infarction. A medico-legal autopsy was conducted. According to the autopsy results, microscopically identified common carotid artery dissections with thrombus formation were considered the cause of infarction. In the present case, macroscopic common carotid artery lesions were relatively mild, and this made diagnosis difficult. However, the correct diagnosis was achieved by a combined analysis of the antemortem images and autopsy results. Thus, in such cases, a combined comprehensive analysis of autopsy results and antemortem clinical images is important to determine the exact cause of death.

Diagnosis of cerebral hemorrhage as a cause of death is often difficult when bodies are in a highly decomposed state. Postmortem imaging can be useful for estimating cause of death in cerebral hemorrhage cases, but the effects of decomposition on imaging findings have not been well studied. We report here two cases in which pre-autopsy computed tomography (CT) accurately detected cerebral hemorrhage in highly decomposed bodies and consequently allowed for careful autopsy dissection. We found that the CT attenuation value of hematoma remained high in intracranial hemorrhagic lesions, probably due to a postmortem increase in the density of hematomas. The high contrast against the background parenchyma enabled the hematomas to be discriminated from the surrounding cerebral parenchyma even in considerably decomposed bodies. However, dispersion and breakdown of the hematomas over time with decomposition appeared to result in contrast reduction. In such cases, hematomas may be missed or their size underestimated on CT. Thus, a comprehensive approach involving autopsy is necessary to determine cause of death for highly decomposed bodies.

The purpose of this research was to investigate the biomechanical properties of the adult human skull and the structural changes that occur with age in both sexes. The heads of 94 Japanese cadavers (54 male cadavers, 40 female cadavers) autopsied in our department were used in this research. A total of 376 cranial samples, four from each skull, were collected. Sample fracture load was measured by a bending test. A statistically significant negative correlation between the sample fracture load and cadaver age was found. This indicates that the stiffness of cranial bones in Japanese individuals decreases with age, and the risk of skull fracture thus probably increases with age. Prior to the bending test, the sample mass, the sample thickness, the ratio of the sample thickness to cadaver stature (ST/CS), and the sample density were measured and calculated. Significant negative correlations between cadaver age and sample thickness, ST/CS, and the sample density were observed only among the female samples. Computerized tomographic (CT) images of 358 cranial samples were available. The computed tomography value (CT value) of cancellous bone which refers to a quantitative scale for describing radiodensity, cancellous bone thickness and cortical bone thickness were measured and calculated. Significant negative correlation between cadaver age and the CT value or cortical bone thickness was observed only among the female samples. These findings suggest that the skull is substantially affected by decreased bone metabolism resulting from osteoporosis. Therefore, osteoporosis prevention and treatment may increase cranial stiffness and reinforce the skull structure, leading to a decrease in the risk of skull fractures.

We present a case of unusual gas embolism in a 73-year-old man who was found in a state of cardiopulmonary arrest with an oxygen-supply tube connected to an intravenous catheter inserted into his median cubital vein. Postmortem computed tomography (PMCT) performed 27 h after death showed systemic gas distribution including intravascular gas, pneumothorax, pneumoperitoneum, pneumomediastinum, pneumoretroperitoneum and gastric emphysema. A second PMCT scan performed 116 h after death showed a marked decrease of air inside the body. The current case shows the importance of PMCT for visualization, quantification, and preservation of evidence for establishment of the cause of death in cases with suspected gas embolism. Our findings also indicate that performance of two PMCT examinations may be useful for differentiation of embolized gas from gas produced by putrefaction.