Postmortem Computed Tomography Scans Research Articles

Postmortem changes in porcine eyes on computed tomography images.

Porcine eyes were examined using postmortem computed tomography (PMCT) under controlled postmortem time and temperature conditions to assess the mechanisms and timing of changes in ocular structure. Eight porcine heads were halved, and PMCT scans were conducted from postmortem interval (PMI) days 0 to 13. CT images were obtained to evaluate the vitreous volumes, vitreous CT values, axial lengths of the eyes, lens dislocation, and intraocular gas. The vitreous volume decreased over time, with the highest median rate of 17.7% at PMI 1, followed by 12.0%, 11.7%, and 11.3% at PMIs 6, 7, and 8, respectively. There was a significant decrease in the axial eye length from PMIs 0 to 1, while the transverse diameter remained unchanged. Lens dislocation was observed in all cases at PMI 9. Receiver operating characteristic analysis using the PMI as the predictive value for the presence of lens dislocation revealed a cutoff value of PMI 6, with an area under the curve of 0.98. Intraocular gas was observed in four cases. In two cases with intraocular gas, intravascular gas appeared to be continuous with the intraocular gas via the ciliary body. Lens dislocation occurred 6days postmortem in porcine eyes at moderate temperatures. Intraocular gas was also observed 6days postmortem, which may have been caused by the influx of intravascular gas into the eye via the ciliary body. These structural changes in the porcine model, may help in estimating the time of death.

Analysis of internal cell temperature variations under different abuse test conditions using embedded temperature sensors

Analysis of internal cell temperature variations under different abuse test conditions using embedded temperature sensors

Exploring radiomic features of lateral cerebral ventricles in postmortem CT for postmortem interval estimation.

The aim of this study is to investigate the potential of radiomic features extracted from postmortem computed tomography (PMCT) scans of the lateral cerebral ventricles (LCVs) to provide information on the time since death, or postmortem interval (PMI), a critical aspect of forensic medicine. Periodic PMCT scans, referred to as "sequential scans", were obtained from twelve corpses with known times of death, ranging from 5.5 to 273h postmortem. Radiomics features were then extracted from the LCVs, and a mixed-effect model, specifically designed for sequential data, was employed to assess the association between feature values and PMI. Four model variants were fitted to the data to identify the best functional form to explain the relationship between the variables. Significant associations were observed for features, the most significant being the median Hounsfield Units (HU) within the LCVs (p < 9.47 × 10⁻⁹), LCVs surface area (p < 4.69 × 10⁻⁶), L-major axis (p < 2.17 × 10⁻⁵), L-minor axis (p < 1.30 × 10⁻⁴), and HU entropy (p < 4.16 × 10⁻⁴). Our findings align with previous studies, supporting a logarithmic model for PMI-related changes in LCV volume and mean HU intensity value. This study highlights the potential of PMCT-based radiomics as source of complementary information that could be integrated into existing methods for PMI estimation. Our results support the application of a quantitative imaging approach in forensic investigations.

Feasibility of new thresholds for coronary artery calcium score using low-tube voltage protocols in postmortem computed tomography1

Feasibility of new thresholds for coronary artery calcium score using low-tube voltage protocols in postmortem computed tomography1

Radiographic, computed tomographic, and histologic characteristics of bone for clinically normal laying hens in a free-range housing system.

Laying hens are increasingly being kept in backyard flocks and considered family pets; however, diagnostic imaging characteristics of bone for clinically normal backyard hens are currently limited. This prospective, descriptive study was to describe radiographic, computed tomographic, and histologic characteristics of bone for a group of clinically normal laying hens housed in conditions comparable to those of backyard flocks. Sixteen 60-week-old Lohmann Brown laying hens were included. Hens were housed in a free-range unit with outdoor access at a university research and teaching farm. Hens were defined as clinically normal by the farm manager and a veterinary researcher in laying hen behavior and welfare. Findings from the horizontal beam, left lateral, sternal radiographs (n=16), postmortem, and whole-body CT scans (n=4) were recorded by a veterinary radiologist and a research technician. Histologic findings for sternal, femoral, and tibiotarsal bone samples (n=5) were recorded by a veterinary pathologist. The most frequent radiographic findings for the sternal carina (keel bone) were smoothly marginated concave deviations of the ventral margin and caudal section fractures. Multiple punctate mineral opacities (PMOs) were present in radiographs and CT images for all hens and were involved in the sternal carina and multiple other bones in the axial and appendicular skeleton. No bone abnormalities were identified in any histologic sections where PMOs were radiographically detected. Authors propose that PMOs are normal radiographic and CT findings in the bones of mature, laying hens and may represent temporary calcium reservoirs formed during osteoclastic activities.

Illustrated cross-sectional computed tomography of the cetacean abdomino-pelvic organs

Computed tomography (CT) is a non-invasive diagnostic imaging modality which can be used to study the anatomy and morphology of live or deceased animals in-situ. In cetaceans, existing CT anatomy studies mostly focused on the head and thoracic regions. Using postmortem CT (PMCT) scans of Indo-Pacific finless porpoises (Neophocaena phocaenoides), this study describes the cross-sectional imaging anatomy of the cetacean abdomino-pelvic organs for the first time. PMCT scans of finless porpoises stranded in Hong Kong waters were reviewed, of which two freshly dead cases, one male and one female, were selected for illustration. In addition, a contrast-enhanced PMCT scan was performed on the female subject as a trial for a PMCT-angiography study (PMCTA) in cetaceans. A total of 18 axial PMCT images were acquired at selected vertebral levels in the abdomen and supplemented with a series of corresponding labeled anatomical diagrams. By applying different image rendering techniques, most osseous and soft tissue structures in the finless porpoise abdomen were successfully depicted and annotated on PMCT, including the male and female reproductive organs in the pelvic region. The application of contrast medium in PMCT created artificial radiodensity differences which improved the ability to visualize and differentiate soft organs and vasculature. The merits and limitations of CT compared to other imaging modalities, as well as the future directions of PMCT in stranding investigation, were discussed. The findings from this study significantly enhance the applications of CT in cetaceans by assisting researchers and veterinarians in the interpretation of cetacean abdomino-pelvic CT for morphological and pathological assessment during clinical or postmortem examination.

Sex estimation from skull measurements of a contemporary Japanese population using three-dimensional computed tomography images

In this study, we assessed the sexual dimorphism of the contemporary Japanese skull and established sex discriminant function equations based on cranial measurements using three-dimensional (3D) computed tomography (CT) images. The CT images of 263 corpses (142 males, 121 females) that underwent postmortem CT scanning and subsequent forensic autopsy were evaluated. Twenty-one cranial measurements were obtained from 3D CT reconstructed images, which extracted only bone data. We performed descriptive statistics and discriminant function analyses for the measurements. Nineteen measurements were significantly larger in males, suggesting sexual dimorphism of the Japanese skulls. Univariate discriminant function analyses using these measurements showed a sex classification accuracy of 57.8–88.2%, and bizygomatic breadth provided the highest correct prediction rate. Multivariate discriminant function analyses offered the most accurate model using seven variables with an estimation rate of 93.9%. Our results suggest that cranial measurements based on 3D CT images may help in the sex estimation of unidentified bodies in a contemporary Japanese population.

Postmortem CT and MRI for detecting bowel obstruction in cases of pediatric sepsis deaths.

This article describes the utility of postmortem CT and MRI in diagnosing pediatric bowel obstruction (BO) as the cause of septic shock-induced death. Six pediatric cases with confirmed septic shock were retrospectively analyzed. Postmortem CT scans revealed clear signs of BO in all cases, with volvulus, intussusception, diaphragmatic hernia, or Meckel's diverticulum identified. MRI scans, performed in three cases, did not provide additional diagnostic information. The presented case series highlights the potential of postmortem CT for diagnosing BO in children, potentially aiding in understanding the cause and manner of death. While MRI offered limited additional benefits, its role in conjunction with CT and autopsy warrants further exploration. Combining these modalities could enhance diagnostic accuracy and provide a more complete picture of the cause of death in children.

Oral health among New Mexican decedents aged 35-44 using NMDID postmortem CT scans

Factors that contribute to general health disparities also contribute to dental health disparities. Using postmortem CT scans from the New Mexico Decedent Image Database, we investigated dental health among recently (2010-2017) deceased New Mexicans. We predicted that race/ethnicity, substance use, and rural living are associated with poorer dental health. The sample (n = 305) represents 32 of the 33 counties in the state, with equal representation of sex and race/ethnicity (European American [EA], Hispanic/Latinx [HL], and Native American [NA]). Data included presence/absence for missing teeth, restorations, abscesses, and decayed teeth. Analyses incorporated logistic regression, odds ratios, and probability plots. Missing teeth correlated with sex and race/ethnicity (HL and NA, compared to EA). Females were 3.8 times more likely and NA decedents were 4.4 times more likely to have missing teeth. High drinking decedents were 1.6 times more likely, and females were 1.7 times more likely to have restorations. Severely decayed teeth and abscesses correlated with race/ethnicity (HL and NA). Our study revealed that high drinking status, sex (female), and being NA or HL negatively affect dental health among New Mexicans. These same factors relate to health disparities in general and indicate long standing issues with health equity in New Mexico.

Diagnostic accuracy of post-mortem computed tomography for fractures of the hyoid-larynx complex.

Post-mortem computed tomography (PMCT) is routinely used at many forensic institutions to guide the following autopsy and is especially useful for diagnosing fractures. This systematic review aims to investigate the sensitivity and specificity of a PMCT scan in fracture diagnosis of the hyoid-larynx complex (HLC) compared to traditional autopsy in cases involving traumatic neck injuries. We searched PubMed, SCOPUS and Web of Science and included papers with cases n ≥ 3 published between January 2000 and April 2023 reporting on PMCT and autopsy findings of fractures of the HLC. The search provided 259 results of which 10 were included. Overall sensitivity and specificity were 0.70 [0.59; 0.79] and 0.92 [0.80; 0.97] for hyoid bone fractures and 0.80 [0.62; 0.91] and 0.76 [0.63; 0.85] for the thyroid cartilage. The results show great variation, and a large range between studies. These results indicate that PMCT cannot replace autopsy in cases with HLC fractures. Future larger prospective studies are needed, examining fracture details, scan protocols and different slice thicknesses using uniform reporting.

Post-mortem Computed Tomography (PMCT) Imaging Compared to Conventional Autopsy in Establishing Cause of Death in Adults

Introduction: The aim of this study was to determine whether the post-mortem computed tomography (PMCT) findings are able to correlate well with the cause of death on conventional autopsy. Materials and methods: From January 2008 until September 2016, total of 60 bodies underwent PMCT scans in the radiology department, followed by conventional autopsies conducted in the forensic department. The radiological findings were interpreted, which were then correlated with the cause of death based on conventional post-mortem autopsy and/or pathological diagnosis. Results: The PMCT findings correlated well with the conventional autopsies. In 28 cases (46.7%), the cause of death was diagnosable based on PMCT alone, in nine cases (15%) the cause was suggestive but required additional information, and in 23 cases (38.3%) the cause was not diagnosable based on PMCT alone. Diagnosable cases included those involving gunshot wounds, sharp and blunt injuries, and lung infections. Causes that could not be diagnosed through PMCT alone included acute myocardial infarction, burns, asphyxiation, drug intoxication and septicemia. Conclusion: PMCT proves to be a valuable and excellent tool for documenting and illustrating bone fractures, abnormal air and fluid accumulation compared to soft tissue injuries, which are better detected in autopsies. However, PMCT alone cannot replace conventional autopsy, which remain the gold standard for establishing the cause of death. Nevertheless, PMCT can serve as useful adjunct in forensic investigations.

Influence of fatigue damage on the impact performance of toughened-interleave carbon fibre epoxy composite laminates

Influence of fatigue damage on the impact performance of toughened-interleave carbon fibre epoxy composite laminates

No relationship found between dental fluctuating asymmetry, birthweight, and birth term in two modern North American samples.

Deciduous dental crowns primarily develop during gestation and early infancy and embody early life stress exposures. Composite measures of dental fluctuating asymmetry (DFA) generated from the deciduous teeth may therefore indicate cumulative gestational stress in developmental origins of health and disease (DOHaD) studies. This study examines whether higher composite measures of deciduous DFA are associated with low birthweight and prematurity, two aspects of birth phenotype consistently associated with increased morbidity and mortality risks in adulthood. We evaluated associations between composite deciduous DFA, birthweight, and birth term in two contemporary North American samples: an autopsy sample from New Mexico (n = 94), and sample from a growth cohort study in Burlington, Ontario (n = 304). Dental metric data for each sample was collected from postmortem CT scans and dental casts, respectively. Composite DFA was estimated using buccolingual (BL) and mesiodistal (MD) crown diameters from paired deciduous teeth. Contrary to expectations, the results of linear regression indicated no significant relationship between birthweight and DFA, or birth term and DFA, in either sample. Deciduous DFA does not predict aspects of birth phenotype associated with gestational stress. Birthweight and birth term are plastic relative to the more developmentally stable deciduous dentition, which may only subtly embody early life stress. We suggest that deciduous DFA should be utilized with caution in DOHaD studies until its relationship with gestational stress is clarified.

Asbestos exposure determined 357 days after death through autopsy: a report of a multidisciplinary approach.

Asbestosis is an interstitial lung disease caused by the inhalation of asbestos fibers and poses a significant risk to individuals working in construction, shipping, mining, and related industries. In a forensic context, postmortem investigations are crucial for accurate diagnosis, for which the gold standard is the histopathological examination. This case report describes the autopsy and related investigations conducted on an 84-year-old man, nearly one year (357 days) after his death. After a post-mortem CT scan, an autoptic investigation was performed, followed by histopathological, immunohistochemical, and scanning electron microscopy examinations. The integration of the evidence from these examinations with previously available personal and clinical information conclusively confirmed the diagnosis of asbestosis. We demonstrated the efficacy and reliability of our diagnostic protocol in detecting asbestosis and asbestos fibers and excluding mesothelioma even in decomposed tissues. According to our findings autopsy remains the diagnostic gold standard in cases of suspected asbestosis within a forensic context, even 1 year after death, therefore it is always highly recommended, even in cases where the body has decomposed.

U-Net-Based Automatic Segmentation of Sphenoid Sinus Fluid in Drowning Cases Using Postmortem CT Images: A Feasibility Study

Detecting sphenoid sinus fluid (SSF) is an additional finding in autopsies for diagnosing drowning. SSF can provide additional forensic evidence through laboratory tests such as diatom and electrolyte analyses. If drowning is suspected, accurately assessing the presence and volume of SSF during an autopsy is crucial. Utilizing postmortem computed tomography (PMCT) images could aid in accurately sampling SSF. Accurately segmenting the region of interest is essential for volume analysis using computed tomography images. However, manual segmentation techniques are labor-intensive and time-consuming, and their success depends on the experience of the observer. Therefore, this study aimed to develop a U-Net–based deep learning model for the automatic segmentation of SSF in drowning cases using PMCT images and to evaluate the performance of the model. We retrospectively reviewed 34 drowning cases in which both PMCT scans and forensic autopsies were performed at our institution. The U-Net architecture of deep learning was used for automatic segmentation. The proposed model achieved the Dice similarity coefficient (DSC) and Intersection over Union (IoU) of a maximum of 95.85% and 92.03%, a minimum of 0% and 0%, and an average of 77.15% and 67.18%, respectively. Although the average DSC and IoU did not show high similarity, this study showed that PMCT images can be used for automatic segmentation of SSF in drowning cases, which could improve the performance with sufficient dataset acquisition and further model training.

Postmortem chest computed tomography in COVID-19: A minimally invasive autopsy method

Performing autopsies in a pandemic scenario is challenging, as the need to understand pathophysiology must be balanced with the contamination risk. A minimally invasive autopsy might be a solution. We present a model that combines radiology and pathology to evaluate postmortem CT lung findings and their correlation with histopathology. Twenty-nine patients with fatal COVID-19 underwent postmortem chest CT, and multiple lung tissue samples were collected. The chest CT scans were analyzed and quantified according to lung involvement in five categories: normal, ground-glass opacities, crazy-paving, small consolidations, and large or lobar consolidations. The lung tissue samples were examined and quantified in three categories: normal lung, exudative diffuse alveolar damage (DAD), and fibroproliferative DAD. A linear index was used to estimate the global severity of involvement by CT and histopathological analysis. There was a positive correlation between patient mean CT and histopathological severity score indexes - Pearson correlation coefficient (R) =0.66 (p=0.0078). When analyzing the mean lung involvement percentage of each finding, positive correlations were found between the normal lung percentage between postmortem CT and histopathology (R=0.65, p=0.0082), as well as between ground-glass opacities in postmortem CT and normal lungs in histopathology (R=0.65, p=0.0086), but negative correlations were observed between ground-glass opacities extension and exudative diffuse alveolar damage in histological slides (R=-0.68, p=0.005). Additionally, it was found is a trend toward a decrease in the percentage of normal lung tissue on the histological slides as the percentage of consolidations in postmortem CT scans increased (R =-0.51, p=0.055). The analysis of the other correlations between the percentage of each finding did not show any significant correlation or correlation trends (p≥0.10). A minimally invasive autopsy is valid. As the severity of involvement is increased in CT, more advanced disease is seen on histopathology. However, we cannot state that one specific radiological category represents a specific pathological correspondent. Ground-glass opacities, in the postmortem stage, must be interpreted with caution, as expiratory lungs may overestimate disease.

Living and post-mortem CT scans in the gross anatomy lab: A study investigating differences in first-year medical students' exam performance and perceptions.

Basic competency in radiological imaging is essential for physicians to identify and manage diseases. An optimal place in which to include imaging in the medical curriculum is during anatomy as students can correlate the 3D anatomy from their body donors with the 2D cross-sectional anatomy. The goal of this project was to enhance first-year medical students' knowledge of cross-sectional imaging in the gross anatomy lab and to investigate whether there are benefits to learning cross sectional imaging via scans from body donors versus living individuals. Student participant performance was evaluated on laboratory practical examinations, CT image questions and spatial anatomical knowledge in the thorax and abdomen sections of gross anatomy. Students learned the cross-sectional imaging during dissections where they accessed the images relevant to their study on Pacsbin, a web-based Digital Imaging and Communication in Medicine viewer, via iPads. Results showed no statistically significant differences in practical examination scores, spatial anatomical knowledge, or identification of anatomical structures on CT image questions between participants who learned from images on body donors versus living individuals. In a questionnaire given at the end of the course, participants cited that the CT images improved their anatomical and imaging knowledge and that they felt better prepared to use imaging software and interpret diagnostic imaging results upon entering clerkships. While there were no differences in academic performance between the groups, positive outcomes regarding student perceptions of anatomical and imaging knowledge and preparedness for use of imaging software were identified in this study.

Finding the Truth: Cadaver and CT scan Study of Differences in Glenoid Width Size in the Indian Population.

Glenoid mass issues have been extensively published in the recent literature. The controversy arose from our need to compare and obtain the appropriate implant size for reverse shoulder arthroplasty patients. Some well-known authors and surgeons say that Indian patients have a smaller glenoid than their Western friends and patients. Therefore, we decided to examine the glenoid size obtained on a computed tomography (CT) scan and the size obtained on a cadaver, preferably the same cadaver in tertiary care medical school. Necessary permissions were obtained from the relatives of the cadaver, the ethical board, the anatomy department, and the radiology department. We evaluated 3D CT scans of 100 patients from our medical college during the global pandemic. Of these, we evaluated only 12 patients whose families agreed to postmortem studies and CT scans. Our research focuses on the shoulder of non-orthopedic diseases conducted at KCGMCH and measured the glenoid height, width, and version using a commercially available computer. The mean age of the patients was 38.5 (range 19-59). The mean glenoid height was 33.8 ± 3.2 mm, maximum glenoid width was 24.3 ± 2.2 mm. The mean glenoid version is 3.48 ± 4 retrospectively. The glenoid width appears to be 23-25 mm on CT scan film, which is similar to cadaver studies. The findings from the cadaver study indicate that the average glenoid size is smaller in the Indian demographic when compared to CT scans. Glenoid width is less in one subset of the population, especially female patients than of the average population than Westerners. However, our studies are limited by the small size of the population and a larger study is recommended in our institution in the future. A better understanding of this glenoid size could help us design a smaller glenoid plate plan, especially for patients in the Indian subcontinent.

Postmortem temporal chest CT and its pathological correlation in piglets

Post-mortem computed tomography (PMCT) is a useful tool to investigate the cause of death. To appropriately use PMCT for cause-of-death analysis, it is necessary to know natural courses after death such as hypostasis in the lungs. We aimed to investigate the natural time-course change of postmortem chest CT findings and its pathological correlation in piglets. Serial chest PMCT scans of four piglets were performed each hour for 24 h and the chronological changes of the lung were evaluated. Immediately after the final CT scan, the autopsy was conducted and bilateral lungs were taken for pathological examination. Two additional piglets were sacrificed and pathological specimens were prepared immediately after death for reference. On pulmonary PMCT, ground glass attenuation (GGA) appeared after the first several hours and increased gradually. Histologically, GGA corresponded to pulmonary edema. The time-related increase in CT attenuation was more prominent in the dorsal lung. Consolidation, endotracheal air defects, and pleural effusion were not observed on PMCT. GGA appeared after the first several hours and increased gradually, and it corresponded to pulmonary edema. GGA in the lung as one of the natural postmortem processes needs to be distinguished from pathogenic findings depending on the time elapsed since death. J. Med. Invest. 71 : 232-236, August, 2024.

On the estimation of hip joint centre location with incomplete bone ossification for foetus-specific neuromusculoskeletal modeling

Childbirth is a complex physiological process in which a foetal neuromusculoskeletal model is of great importance to develop realistic delivery simulations and associated complication analyses. However, the estimation of hip joint centre (HJC) in foetuses remains a challenging issue. Thus, this paper aims to propose and evaluate a new approach to locate the HJC in foetuses. Hip CT-scans from 25 children (F = 11, age = 5.5 ± 2.6 years, height = 117 ± 21 cm, mass = 26 kg ± 9.5 kg) were used to propose and evaluate the novel acetabulum sphere fitting process to locate the HJC. This new approach using the acetabulum surface was applied to a population of 57 post-mortem foetal CT scans to locate the HJC as well as to determine associated regression equations using multiple linear regression. As results, the average distance between the HJC located using acetabulum sphere fitting and femoral head sphere fitting in children was 1.5 ± 0.7 mm. The average prediction error using our developed foetal HJC regression equations was 3.0 ± 1.5 mm, even though the equation for the x coordinate had a poor value of R2 (R2 for the x coordinate = 0.488). The present study suggests that the use of the acetabulum sphere fitting approach is a valid and accurate method to locate the HJC in children, and then can be extrapolated to get an estimation of the HJC in foetuses with incomplete bone ossification. Therefore, the present paper can be used as a guideline for foetus specific neuromusculoskeletal modelling.