Postmortem computed tomography imaging of negative pressure pulmonary edema induced by rice cakes: A case report.

Airway obstruction by foreign bodies or laryngospasms often results in negative pressure pulmonary edema (NPPE). NPPE can develop despite the removal of airway obstruction. This is well-known among clinicians, particularly anesthesiologists, emergency physicians, pediatricians, and radiologists. Computed tomography (CT) features of NPPE include diffuse central ground-glass opacities and thickening of the bronchovascular bundles and bronchial walls. NPPE can also occur after strangulation or smothering with a plastic bag, and is sometimes fatal. Nevertheless, no reports of NPPE are available in forensic journals, and forensic practitioners may not be dedicating the necessary attention to this condition. Recently, the use of postmortem CT as an auxiliary imaging modality for autopsies has increased among forensic institutions in Japan. Understanding the mechanisms and CT findings of NPPE will be useful for forensic practitioners. Herein, we present a case wherein the postmortem CT image revealed NPPE resulting from the obstruction of the airway induced by rice cakes.

Artificial intelligence-based forensic sex determination of East Asian cadavers from skull morphology.

Identification of unknown cadavers is an important task for forensic scientists. Forensic scientists attempt to identify skeletal remains based on factors including age, sex, and dental treatment remains. Forensic scientists commonly consider skull or pelvic shape to evaluate the sex; however, these evaluations require sufficient experience and knowledge and lack objectivity and reproducibility. To ensure objectivity and reproducibility for sex evaluation, we applied a gated attention-based multiple-instance learning model to three-dimensional (3D) skull images reconstructed from postmortem head computed tomography scans. We preprocessed the images, trained with 864 training data, validated the model with 124 validation data, and evaluated the performance of our model in terms of accuracy with 246 test data. Furthermore, three forensic scientists evaluated the 3D skull images, and their performances were compared with those of the model. Our model showed an accuracy of 0.93, which was higher than that of the forensic scientists. Our model primarily focused on the entire skull owing to visualization but focused less on the areas often investigated by forensic scientists. In summary, our model may serve as a supportive tool to identify cadaver sex based on skull shape. Further studies are required to improve the model's performance.

Deep Neural Networks-Based Age Estimation of Cadavers Using CT Imaging of Vertebrae.

Although age estimation upon death is important in the identification of unknown cadavers for forensic scientists, to the best of our knowledge, no study has examined the utility of deep neural network (DNN) models for age estimation among cadavers. We performed a postmortem computed tomography (CT) examination of 1000 and 500 male and female cadavers, respectively. These CT slices were converted into 3-dimensional images, and only the thoracolumbar region was extracted. Eighty percent of them were categorized as training datasets and the others as test datasets for both sexes. We fine-tuned the ResNet152 models using the training datasets. We conducted 4-fold cross-validation, and the mean absolute error (MAE) of the test datasets was calculated using the ensemble learning of four ResNet152 models. Consequently, the MAE of the male and female models was 7.25 and 7.16, respectively. Our study shows that DNN models can be useful tools in the field of forensic medicine.

Application of Teeth in Toxicological Analysis of Decomposed Cadavers Using a Carbamazepine-Administered Rat Model.

In a regular autopsy, blood and organs are used to quantify drug and toxicant concentrations; however, specimens such as blood cannot be collected from highly decomposed corpses, making the quantification of drug and toxicants impossible. This study aimed to estimate the blood carbamazepine (CBZ) concentration from teeth, a part of the human body that is best preserved after death. We sampled teeth and blood of rats administered CBZ. The correlation between the tooth and serum CBZ concentrations was analyzed. Rats were euthanized after CBZ administration and kept at 22 °C for 0 to 15 days before sampling the teeth and measuring the CBZ concentration. Undecalcified, fresh, frozen sections of rat teeth were prepared, and CBZ localization was evaluated. CBZ concentrations in both teeth and cardiac blood peaked at 60 min after administration and increased in a dose-dependent manner. CBZ concentration in teeth did not substantially change after death, with high CBZ distribution being observed in the pulp cavity. The tooth and serum CBZ concentrations were highly correlated, suggesting that the measurement of toxicant concentration in sampled teeth would allow for the estimation of blood toxicant concentration in highly decomposed corpses.

Pentobarbital overdose: A case of contract killing.

Suicides by pentobarbital overdose have increased since about 2012, which appear to be influenced by technical information on active euthanasia that has spread over the Internet. We encountered a pentobarbital poisoning case of a patient with amyotrophic lateral sclerosis. A caregiver found the patient unconscious immediately after two visitors left the room. The patient was immediately transferred to the emergency hospital but eventually declared dead. A fatal concentration of pentobarbital was detected in peripheral blood samples collected in the emergency hospital and during autopsy (53.8 µg/mL and 29.4 µg/mL, respectively). Because the ratios of pentobarbital concentrations between the gastric contents and peripheral blood were 35 and 29 in the hospital and autopsy samples, respectively, it is likely that pentobarbital was administered via the gastrostomy tube. The patient had contacted the visitors through social media. Although the patient had requested the doctor perform active euthanasia and expressed a desire to end their life on social media, nobody had noticed the plan to commit suicide.

Estimating the age at death for forensic cases using quantitative computed tomography.

Estimation of the age at death is an important task for forensic scientists. Although the correlation between age and bone mineral density is already known, including for cadavers, to our knowledge, there are no published studies on age estimation with quantitative computed tomography. Quantitative computed tomography can be used to measure bone mineral density based on the mean computed tomography value of the cancellous bone. As this value cannot be calculated in putrefied cases, we modified quantitative computed tomography to calculate the bone mineral density from regions of the bone with mean computed tomography values of 50-350 Hounsfield units. We aimed to examine whether this method could be used for age estimation. We examined 171 male and 106 female cadavers, some of which were putrefied. We performed univariate linear regression analysis for age at death and bone mineral density. The resultant intercept, slope, and root mean square error were 91.3, - 0.20 (p < 0.0001), and 11.4, respectively, for male cadavers, and 96.1, - 0.23 (p < 0.0001), and 11.0, respectively, for female cadavers. We evaluated this regression formula by using 10-fold cross-validation, resulting in a coefficient of determination of 0.33 for male cadavers and 0.42 for female cadavers. The modified quantitative computed tomography method may be of assistance in estimating age at death, even in putrefied cases.

Alcohol abuse as a potential risk factor of solitary death among people living alone: a cross-sectional study in Kyoto, Japan.

BACKGROUND: Solitary death is an emerging public health problem in developed countries. Alcohol abuse is associated with social isolation and excess mortality. However, data on the association between alcohol abuse and solitary death are limited. Our purposes were to assess whether alcohol abuse is associated with a long interval from death to discovery among people living alone. METHODS: This is a cross-sectional study using the data on subjects from the largest forensic database in Kyoto, Japan, from February 2012 to December 2015. Solitary death was defined as a phenomenon of dying alone at home and remaining undiscovered for more than 1 week. All the subjects who lived alone and aged over 18 at the time of death were included in the study. The presence of alcohol abuse was identified via an investigation during home visits. Proportional ratios were calculated using a fitted logit model to evaluate the association of alcohol abuse on solitary death after adjusting for possible confounders. RESULTS: A total of 235 subjects were included in the analysis. The mean age (standard deviation) of subjects at the time of death was 63.4 (15.1) years, and approximately 61.8% and 38.9% of subjects in the alcohol and non-alcohol abuse groups, respectively, experienced solitary death. Multivariable analyses revealed that alcohol abuse was associated with solitary death (adjusted proportion ratio: 1.50; 95% confidence interval: 1.12-2.00). CONCLUSIONS: The findings of this study could help identify individuals at higher risk of solitary death. Moreover, calling the attention of people with alcohol abuse may be beneficial to prevent solitary death.

The coronary artery calcification severity on postmortem CT could be a clue for the diagnosis of sudden cardiac death.

About two-thirds of sudden deaths are sudden cardiac deaths (SCD), and ischemic heart disease (IHD) accounts for 60% of these. Although an autopsy needs to be performed to prove SCD, the forensic autopsy rate is very low in Japan. To diagnose the cause of death, postmortem computed tomography (PMCT) is often performed. Because coronary artery calcification (CAC) is a risk factor in cardiac diseases such as IHD and its severity can be evaluated with CT, we examined its ability to diagnose SCD. We collected 104 autopsy cases with CT scans. On the basis of the autopsy report, we separated the cases into two groups: SCD suspected as the cause of death and SCD not suspected. We calculated each CAC severity with the Agatston score from the CT images. Cases with Agatston scores of more than 400 were labeled as severe. The relationship between SCD and CAC severity was confirmed with Fisher's exact test (p < 0.05). The sensitivity and specificity of CAC severity for SCD were 20.3% and 97.5%, respectively, and the positive likelihood ratio was 8.1. Severe CAC can increase the probability of SCD. In cases in which only PMCT can be performed, this finding can be helpful for diagnosing SCD.

Rapid infusion of excessive phenytoin: A newborn autopsy case.

The patient was a two-day-old female infant. The patient's mother was a primigravid in her 20 s who developed premature abruption of the normal placenta on the first day of the 33rd week of gestation. The infant was born by emergency cesarean section with severe neonatal asphyxia with a birth weight of 1928 g. Spontaneous circulation was returned 11 min after birth. The infant was treated under mechanical ventilation in the neonatal intensive care unit, and phenobarbital was administered for repeated seizures. On day 2, spontaneous respiration was observed; however, the patient developed seizures repeatedly. The dose of phenobarbital reached the maximum and was switched to midazolam. In the early morning of day 3, while midazolam was administered up to the maximum dose, the infant developed status epilepticus, and the anticonvulsant drug was changed to phenytoin. Due to a calculation error, the intravenous administration of phenytoin was started at 400 mg/30 min, which is 10-fold of the normal dose. Six minutes later, after 80 mg was administered, the administration was stopped due to a drop in blood pressure; however, the infant died of cardiac arrest. An autopsy, which was performed approximately 25 h after death, revealed the blood phenytoin concentration in the heart was 63.85 µg/mL. The cause of death was determined to be acute phenytoin toxicity. This is the first fatal case reported of the blood concentration of phenytoin caused by rapid intravenous administration.

A cross-sectional cadaveric study of the correlation between genital organ measurements, serum testosterone, and serum prostate-specific antigen levels in Japanese male subjects.

Association of organ sizes in the genitalia have long been a topic of interest for the general public. However, factors such as selection bias, embarrassment, and invasive testing have hindered studies on living individuals. We obtained measurements of penile size, testicular weight, and prostate weight, and conducted related serum testing on 63 Japanese male adults who died of unexpected reasons and underwent autopsy from 2009 to 2013. Micropenis was seen in 7 subjects (11.1%) as determined by flaccid penile length. Penile measurements were mainly correlated with body weight, testicular weight with age and body mass index, and prostate weight with age and serum prostate-specific antigen level. No correlation was detected between testosterone and any genital organ measurements. Interestingly, penile circumference showed no correlation to any of the penile length measurements. Prostate weight showed a significant positive correlation with penile circumference, penile stretched length, and testicular weight. Although the direct clinical implications are unclear, utilizing autopsy provided insight into genital organ measurements free of patient selection bias and other disadvantages of live patient testing. With a larger sample size, autopsy studies may be of use to future adjustment of nomograms.

Estimation of Cadaveric Age by Ultrasonography.

(1) Background: While decreasing bone mineral density (BMD) with age in living people has been well documented, a correlation between age and bone mineral density in deceased people has only been reported in a few studies. A correlation between age and BMD in deceased people was investigated as an objective tool for age estimation of unidentified remains. (2) Methods: The Bone Area Ratio (BAR) was measured in 402 autopsy cases (143 females and 259 males over the age of 20). (3) Results: The correlation coefficient in the females was r = -0.5476, and the correlation coefficient in the males was r = -0.2166, indicating a stronger correlation in females than in males. A comparison of the BAR values in the deceased females for each age group with that in live females found no significant differences in the BAR values. BAR values in the deceased were similar to in live individuals, and this did not change with duration of the postmortem interval. (4) Conclusions: Measuring the BAR value based on bone mass using ultrasonic waves is rapid and easy, even for those lacking forensic training, and may be used to estimate the age of an individual and the likelihood of fracture due to trauma.

Simple, Frequent Indicator for Personal Identification-Postmortem and Antemortem Abdominal Computed Tomography Findings of a Charred Body.

Postmortem personal identification in forensic science is performed using various methods. However, severely burnt bodies are hard to identify using odontological or skeletal features because of carbonization, and sometimes DNA profiling is impracticable because of the unavailability of the relatives. We present a case of a burn victim found after a house fire. Personal identification was attempted, but the body was heavily charred to the bones and the use of physical appearance was impracticable. There were no known relatives or personal belongings of the deceased for comparison of DNA typing. We obtained a series of abdominal computed tomography (CT) scans taken antemortem and found bilateral multiple renal cysts, left renal artery calcification, and a big right inguinal hernia, which matched the deceased's postmortem CT findings and autopsy findings. To date, studies of identification by CT have acted for a rise in precision, but they require complicated calculation or high graphical methods. Calcification of the arteries or renal cysts seen in our case are very common lesions present in many adults with abundant variation; thus, they may be helpful as simple indicators for identification.

Perforation rates in double latex gloves and protective effects of outer work gloves in a postmortem examination room: A STROBE-compliant study.

Medical staff face the risk of exposure to blood-borne infectious agents during postmortem examinations. This study investigated the effectiveness of non-slip work gloves worn over 2 layers of surgical latex gloves (outer and inner gloves) as a means of reducing hand and finger injuries. Complete sets of outer and inner gloves worn during postmortem examinations were collected from participating forensic staff. Latex gloves were categorized into 2 groups based on the users' actions during the examination: the wearing group if the wearer wore their work gloves continuously without interruption, and the taking-off group if the wearer removed them at least once. Perforation rates, locations, and shapes were compared between these groups. Outer-glove perforation occurred significantly more often in the taking-off group (n = 102 pairs) than in the wearing group (n = 91 pairs) (30.4% vs 3.8%, P < .001). Inner-glove perforation occurred at rates of 2.0% and 0.5% (P = .38), respectively. The wearers did not incur hand or finger injuries. Perforation rates were similar between the dominant and non-dominant hands (P = .18). Regarding location, gloves were punctured most frequently at the thumb, followed by the index finger. Most examiners (85.6%) did not notice the perforation when the damage occurred. Therefore, we could not confirm that a specific operation within a set of plural operations affected the rate of perforation. Additionally, we could not prove a relationship between glove perforation and each operation performed with/without work gloves. The perforation appearances varied greatly in shape and size, suggesting multiple causes of perforation. The continuous (i.e., uninterrupted) wear of work gloves during postmortem examinations reduced the incidence of perforations in both latex glove layers and thus reduced the risk of hand and finger injury.

Postmortem plasma pentraxin 3 is a useful marker of fatal acute coronary syndrome.

Pentraxin 3 (PTX3) is an acute-phase protein that belongs to the pentraxin superfamily. Recently, many clinical studies have demonstrated that plasma PTX3 concentrations rapidly increase in patients with the acute coronary syndrome (ACS). The aim of this study was to evaluate the forensic utility of postmortem plasma PTX3 as a marker of fatal ACS. We compared the plasma PTX3 concentration in cadavers with suspected fatal ACS to that exhibited in control cases (e.g., asphyxia and immediate death due to a fatal injury). The ACS groups included a coronary stenosis group, which exhibited apparent coronary stenosis, but an absence of coronary thrombi, a coronary thrombi group with thrombi found in the coronary artery, and a group of myocardial rupture following an acute myocardial infarction. The plasma PTX3 concentration was significantly higher in the coronary thrombi group than the control group and other ACS groups. The postmortem plasma PTX3 concentration was higher than the clinical reference values, which appeared to be caused by a postmortem release from circulating neutrophils. In conclusion, although the clinical reference value cannot be applied to postmortem samples, the postmortem plasma PTX3 concentration may be a useful marker of death occurring immediately after the onset of fatal ACS.

The genome profiling method can be applied for species identification of biological materials collected at crime scenes.

BACKGROUND: Various biological materials unrelated to humans are found at crime scenes and it is often important to elucidate the origin of these materials. A genetic locus common to several species is conventionally PCR-amplified with universal primers to identify species. However, not all species can be identified using a single locus. In this study, DNA from 13 commonly handled taxa was analyzed to identify species by a genome profiling (GP) method, which involves random PCR and temperature gradient gel electrophoresis. RESULTS: In a clustering analysis, we successfully obtained a single cluster for each species. CONCLUSION: The GP method is cost-effective and does not require advanced techniques and knowledge in molecular biology. The random sampling of the whole genome using multiple primers provides substantial genomic information. Therefore, the method is effective for classifying a wide range of species, including animals, plants, and insects, and is useful for crime scene investigations.

Autoerotic asphyxia using a plastic bag loosely covering the head over a gas mask.

Autoerotic death is defined as the accidental death of an individual while masturbating, caused by a device or material used to enhance the sexual response. Here we report an autopsy case of autoerotic death and review the literature. A healthy, single, 33-year-old Japanese male was found dead in his room in a prone position. He was wearing a used gas mask and a plastic bag over his head; the opening of that bag was loosely secured around the neck with a belt. He had no underwear beneath his upper and lower work clothes and the zipper of his pants was open. Adult magazines and DVDs featuring male subjects and other adult toys were found in his room. Images of people wearing gas masks and rubber suits, as well as of individuals whose whole bodies were tied with ropes, were discovered on his personal computer. Records of purchasing full-body tights were also found. Lesions and injuries that could have caused his death were not found in the autopsy or in any of the various examinations. The cause of death was determined to be suffocation assumed to be caused by the plastic bag covering the mask's ventilation. Suicide and homicide were ruled out based on the police investigation of the scene of the victim's death and the attendant circumstances and environment. The death was thus determined to be an accident. We see no major differences in the feature of autoerotic death between Japanese cases and those in the Western countries.

Rare atlas fracture detected using postmortem computed tomography: A case report.

We report the autopsy of a traffic accident victim with a rare atlas fracture. The deceased was 52-year-old man found dead on the road because of a traffic accident. We performed a postmortem computed tomography and an autopsy on the body. The sagittal reformation image of postmortem computed tomography showed a vertically separated anterior arch of atlas, suggesting a "horizontal fracture." Therefore, we assumed that cervical hyperextension may have been one of the forces that affected him during the accident. Minor spinal cord injury was also noted. In this case, postmortem computed tomography played an important role in detecting the spinal cord injury, considering the mechanism of the traffic accident, and supported the autopsy.

Infant fatality case with excessive chylous ascites.

An 11-month-old boy with marked abdominal distension was found dead in the prone position at home. Since there were many bruises in the non-protruding regions of the head, face, and abdomen, a medicolegal autopsy was performed the following day. The boy was smaller than average (height: 68.5 cm; weight: 7.8 kg); his extremities were thin; and his abdomen was remarkably bulging. Chylous ascites (1600 mL) was observed in the peritoneal cavity and chylous pleural effusion (left: 5 mL; right: 10 mL) in the thoracic cavity. A fibrous induration, approximately 2.0 × 1.5 cm in size, was observed in the root of the small bowel mesentery. Congenital chylothorax and chylous ascites were suspected. However, the remarkably withered thymus and an old injury in the superior labial frenulum suggested that the chylous ascites may have been further deteriorated by injuries sustained during physical abuse. Examination suggested that the death was sudden. Thus, we inferred that the cause of death was circulatory and respiratory failure due to excessive chylous ascites. Among the reported cases of chylous ascites in pediatric patients, some patients experiencing abuse were identified on the basis of their chief complaints of vomiting or abdominal distension. Medical and child welfare staff should be made aware of this information.

Comparison between Temperature Gradient Gel Electrophoresis of Bacterial 16S rDNA and Diatom Test for Diagnosis of Drowning.

When a body is discovered in water, it is difficult to conclude whether the cause of death was drowning, even today. Although diatom testing by the digestive method is classical, we hypothesized that aquatic bacteria, as well as diatoms, might be detected in drowned bodies, and conducted temperature gradient gel electrophoresis (TGGE)-targeting 16S rDNA. DNA was extracted from the site water, and from heart blood and liver samples from 27 bodies concluded as drowning deaths by autopsy and subjected to TGGE after amplification of 16S rDNA by polymerase chain reaction. We observed whether the feature point of each 16S rDNA from the site water and blood or liver samples matched. Considerably higher correspondence was observed in drowned bodies, and the rate was higher than that achieved with the digestive method. Moreover, TGGE is safer than the digestive method. Our study suggests that this method can aid diagnosis of drowning.