Postmortem Computed Tomography Images Research Articles

Post-mortem pulmonary tuberculosis: comparison of available diagnostic methods.

Tuberculosis (TB) caused by Mycobacterium tuberculosis remains a serious public health threat with the World Health Organisation (WHO) reporting 5.8 million cases and 1.3 million deaths in the year 2020 due to TB. TB can be diagnosed by imaging, histopathological and bacteriological methods with culture remaining the gold standard. This study was performed to look at the sensitivity and specificity of post-mortem computed tomography (PMCT) imaging when compared to culture in diagnosing pulmonary tuberculosis. This was a retrospective comparative study looking at post mortem cases where lung tissue samples sent for TB culture at Hospital Kuala Lumpur were compared against PMCT imaging. Exclusion criteria included contaminated samples, decomposed cases, immunocompromised subjects and those below 18 years of age. Subjects included 80 medico-legal autopsy cases at the National Institute of Forensic Medicine, Hospital Kuala Lumpur, Malaysia who had whole body PMCT done in accordance with the Institute's protocol and tissue samples sent for bacteriology culture for tuberculosis. PMCT findings were positively associated with acid-fast organisms in 23.5 out of 33 cases (71.2%). Our study also showed that PMCT had a sensitivity of 71.3% and specificity of 54.3% (95% CI: 39.5-68.4) in diagnosing TB based on the protocol set in this study. This study showed that there was relatively good agreement between radiological PMCT findings and bacterial culture, suggesting that radiological examination is a relatively reliable tool for preliminary screening and possible diagnosis of TB prior to a postmortem examination which would be beneficial in reducing the risk of transmission of TB to health workers during autopsy.

Examination of postmortem changes in the lungs, trachea, and bronchi in a rat model imaged with small-animal computed tomography.

As less autopsies are performed, the need for postmortem computed tomography (PMCT) as an alternative is increasing. It is important to know how postmortem changes over time are reflected on CT, in order to improve the diagnostic capability of PMCT and replace forensic pathology evaluations such as time of death estimation. In this study, we examined temporal changes on postmortem chest CT images of a rat model. After acquiring antemortem images under isoflurane inhalation anesthesia, the rats were euthanized with a rapid intravenous injection of anesthetics. From immediately after death to 48 hours postmortem, chest images were acquired using small-animal CT. The 3D images were then evaluated on a workstation to measure the antemortem and postmortem air content in the lungs, trachea, and bronchi over time. The air content in the lungs decreased, but the air content of the trachea and bronchi temporarily increased 1-12 hours postmortem, then decreased at 48 hours postmortem. Therefore, the measurement of trachea and bronchi volumes on PMCT could be an objective way to estimate the time of death. While the air content of the lungs decreased, the volume of the trachea and bronchi temporarily increased after death, indicating the potential to use such measurements to estimate time of death.

Estimating age at death by Hausdorff distance analyses of the fourth lumbar vertebral bodies using 3D postmortem CT images.

The existing methods for determining adult age from human skeletons are mostly qualitative. However, a shift in quantifying age-related skeletal morphology on a quantitative scale is emerging. This study describes an intuitive variable extraction technique and quantifies skeletal morphology in continuous data to understand their aging pattern. A total of 200 postmortem CT images from the deceased aged 25-99years (130 males, 70 females) who underwent forensic death investigations were used in the study. The 3D volume of the fourth lumbar vertebral body was segmented, smoothed, and post-processed using the open-source software ITK-SNAP and MeshLab, respectively. To measure the extent of 3D shape deformity due to aging, the Hausdorff distance (HD) analysis was performed. In our context, the maximum Hausdorff distance (maxHD) was chosen as a metric, which was subsequently studied for its correlation with age at death. A strong statistically significant positive correlation (P < 0.001) between maxHD and age at death was observed in both sexes (Spearman's rho = 0.742, male; Spearman's rho = 0.729, female). In simple linear regression analyses, the regression equations obtained yielded the standard error of estimates of 12.5years and 13.1years for males and females, respectively. Our study demonstrated that age-related vertebral morphology could be described using the HD method. Moreover, it encourages further studies with larger sample sizes and on other population backgrounds to validate the methodology.

A novel method to estimate adult age from the lumbar vertebral body using 3D PMCT images in Japanese

This study evaluated the age-related changes in the vertebral body using 3D Postmortem CT (PMCT) images and proposed an alternative age estimation formula. The PMCT images of 200 deceased individuals aged 25 to 99 years (126 males, 74 females) were retrospectively reviewed and included in the study. Using the open-source software ITK-SNAP and MeshLab, a 3D surface mesh of the fourth lumbar vertebral body (L4) and its convex hull models were created from the PMCT data. Using their inbuilt tools, volumes (in mm3) of the L4 surface mesh and convex hull models were subsequently computed. We derived VD, defined as the difference in volumes between the convex hull and L4 surface mesh normalized by L4 mesh volume, and VR, defined as the ratio of L4 mesh volume to convex hull volume based on individual L4. Correlation and regression analyses were performed between VD, VR, and chronological age. A statistically significant positive correlation (P < 0.001) between chronological age and VD, (rs = 0.764, males; rs = 0.725, females), and a significant negative correlation between chronological age and VR (rs = -0.764, males; rs = -0.725, females) was obtained in both sexes. The lowest standard error of the estimate was demonstrated by the VR at 11.9 years and 12.5 years for males and females, respectively. As such, their regression models to estimate adult age were Age = 248.9–2.5VR years, males; Age = 258.1–2.5VR years, females. These regression equations may be useful for estimating age in Japanese adults in forensic settings.

Implementation of a personal identification system using alveolar bone images

ObjectiveIn recent years, personal identification has been performed using antemortem panoramic X-ray images and postmortem-CT images. Using these, we have developed a personal identification method that focuses on the alveolar bone. This study examined the effectiveness of this method and aimed to implement a reproducible system. Materials and methodsFor personal identification, a total of 633 CT images and panoramic X-ray images belonging to three groups with different conditions were used. These images were 160 sets in the same person group and 96,820 in the other groups. The similarity of alveolar bone images was calculated using the landmark method of Procrustes analysis. The processes were system implemented and the methodology was validated. ResultsThe ability to identify between the same person group and other person groups showed 0.9769 as the area under the curve (AUC: ROC curve). At the cutoff value of 4.978, there was no false rejection rate, but false acceptance rate was slightly higher. ConclusionThis method was useful as a screening method for personal identification. In addition, system implementation was efficient and reduced human error. In the future, we aim to realize a more efficient personal identification method using distortion-corrected images and including auto-detective landmarks using deep learning.

Aortic calcification: A postmortem CT validation study in a middle-aged population

BackgroundComputed tomography (CT)-detected aortic calcification is strongly associated with aortic stiffness and is an accurate predictor of cardiovascular and all-cause mortality and cognitive decline. Some previous pathologic studies have shown calcium accumulation in the medial layer of the vessel wall, while others have suggested localisation in the atherosclerotic intimal layer. ObjectivesThe aim of this study was to histologically validate CT findings of aortic calcification for detectability and location in the aortic wall. MethodsWe acquired postmortem CT images and collected 170 aortic tissue samples from five different locations in the thoracic and abdominal aorta of 40 individuals who underwent autopsy. Microscopic slides were stained with haematoxylin and eosin and elastic van Gieson stain. Calcified lesions were characterised and calcifications were manually annotated in the intima and media. The presence and morphology of calcifications were scored on CT images. ResultsThe mean age of the autopsied individuals was 63 years, and 28 % died of cardiovascular disease. Calcifications were present in 74/170 (44 %) samples. Calcification was more common in the abdominal aorta than in the thoracic aorta. In all samples with calcifications, 99 % were located in the intimal layer. Only 16/170 samples had a small amount of medial arterial calcification. The histological results showed an 85 % concordance for the presence or absence of CT calcifications. There was complete inter-method agreement for annularity of calcifications in 68 % of the samples (linear weighted kappa 0.68 (95 %CI 0.60–0.77). ConclusionsAortic calcifications visible on CT are located in the intimal layer of the abdominal aorta wall, at least in aortas that are not aneurysmatic or dissected. The presence and annularity of these calcifications can be reliably determined by CT.

Diagnosing Drowning in Postmortem CT Images Using Artificial Intelligence.

Imaging features of the lung in postmortem computed tomography (CT) scans have been reported in drowning cases. However, it is difficult for forensic pathologists with limited experience to distinguish subtle differences in CT images. In this study, artificial intelligence (AI) with deep learning capability was used to diagnose drowning in postmortem CT images, and its performance was evaluated. The samples consisted of high-resolution CT images of the chest of 153 drowned and 160 non-drowned bodies captured by an 8- or 64-row multislice CT system. The images were captured with an image slice thickness of 1.0 mm and spacing of 30 mm, and 28 images were typically captured. A modified AlexNet was used as the AI architecture. The output result was the drowning probability for each component image. To evaluate the performance of the proposed model, the area under the receiver operating characteristic curve (AUC) was analyzed, and the AUC value of 0.95 was obtained. This indicates that the proposed AI architecture is a useful and powerful complementary testing approach for diagnosing drowning in postmortem CT images. Notably, the accuracy was 81% (62/77) for cases in which resuscitation was performed, and 92% (216/236) for cases in which resuscitation was not attempted. Therefore, the proposed AI method should not be used to diagnose the cause of death when aggressive cardiopulmonary resuscitation was performed. Additionally, because honeycomb lungs are likely to exhibit different morphologies, emphysema cases should also be treated with caution when the proposed AI method is used to diagnose drowning.

Deep Learning-Based Diagnosis of Fatal Hypothermia Using Post-Mortem Computed Tomography.

In forensic medicine, fatal hypothermia diagnosis is not always easy because findings are not specific, especially if traumatized. Post-mortem computed tomography (PMCT) is a useful adjunct to the cause-of-death diagnosis and some qualitative image character analysis, such as diffuse hyperaeration with decreased vascularity or pulmonary emphysema, have also been utilized for fatal hypothermia. However, it is challenging for inexperienced forensic pathologists to recognize the subtle differences of fatal hypothermia in PMCT images. In this study, we developed a deep learning-based diagnosis system for fatal hypothermia and explored the possibility of being an alternative diagnostic for forensic pathologists. An in-house dataset of forensic autopsy proven samples was used for the development and performance evaluation of the deep learning system. We used the area under the receiver operating characteristic curve (AUC) of the system for evaluation, and a human-expert comparable AUC value of 0.905, sensitivity of 0.948, and specificity of 0.741 were achieved. The experimental results clearly demonstrated the usefulness and feasibility of the deep learning system for fatal hypothermia diagnosis.

Validity of dental findings for identification by postmortem computed tomography

Postmortem computed tomography (PMCT) images help identify individuals and extract information from corpses. PMCT may substitute for a standard examination when bodies are severely damaged or when resources are limited in a mass fatality incident. In such situations, the dental information revealed by PMCT has the potential to narrow down candidates for identification further. However, the validity of the dental findings obtained from PMCT images remains unclear. In this study, we investigated the validity of dental findings on PMCT images compared to regular dental examinations as the reference standard. We routinely collected PMCT images of 148 unidentified corpses and compared the dental findings of each tooth obtained from PMCT with those of a regular dental examination. The validity of dental findings of PMCT was measured by sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). We also evaluated the accuracy of dental findings per corpse using 32 teeth as the denominator. The dental findings with high sensitivity and high specificity were a present tooth (0.96 and 0.97), a missing tooth (0.97 and 0.97), pontic (0.92 and 1.00), a dental implant (1.00 and 1.00), and a root filling (0.94 and 0.99). The mean accuracy of the dental findings per corpse in PMCT was 95.6% (standard deviation: 6.9, minimum ≤ median ≤ maximum: 65.6 ≤ 100 ≤ 100). The number of corpses with 100% accuracy in the dental findings was 81 (54.7%). The information obtained in this study highlights the potential use of PMCT during human identification in several settings with limited resources, such as the number of specialists present and the condition of the corpses.

POST-MORTEM INTERVAL ESTIMATION BASED ON LIVER AND STRIATED MUSCLE COMPUTED TOMOGRAPHY ATTENUATIONS IN RATS

OBJECTIVE: The interest on post-mortem computed tomographic studies targeting post-mortem interval (PMI) estimations is increasing. Most studies have been conducted in an uncontrolled or relatively less controlled condition. However, this study investigates the usefulness of computed tomography attenuations of the liver and striated muscles in PMI estimation under strictly controlled environmental conditions. MATERIAL AND METHODS: Post-mortem computed tomography images of 30 Wistar Albino rats were obtained in the first 30 min after death and 12, 24, 36, 48, 72, 96, 120, 144 and 168-hours following death. Repeated attenuations of both thelateral lobes of the liver and paraspinal muscle were recorded in 0.12-cm2 regions of interest. RESULTS: The attenuation values of the liver and paraspinal muscles were higher 12-hour post-mortem. A significant difference was observed between the images obtained 30 minutes post-mortem and those obtained 12 hours post-mortem in both male (p=0.01) and female rats (p=0.01). Different cut-off attenuation values for the liver and muscle tissue were determined to estimate the post-mortem interval. CONCLUSIONS: The use of attenuation values of the liver and striated muscles with the proposed model was found to be beneficial for the determination of PMI. The cut-off values of attenuation, especially for the liver, can be used in the delimitation of the post-mortem interval.

Use of Post-Mortem Computed Tomography During the COVID-19 Pandemic: The Malaysian Experience.

COVID-19 was declared a pandemic by the World Health Organization (WHO). COVID-19 is highly contagious, making it a threat to healthcare workers, including those working in mortuaries. Therefore, it is important to determine if the cause of death (COD) could be identified using limited autopsy, diagnostic tests and post-mortem imaging modalities instead of full autopsy. This study aims to examine the effectiveness of post-mortem imaging, specifically post-mortem computed tomography (PMCT) at determining the COD during a pandemic. This cross-sectional study included 172 subjects with suspected or unknown COVID-19 status brought in dead to the institute's mortuary during the pandemic in Malaysia. PMCT images reported by forensic radiologists and their agreement with conventional autopsy findings by forensic pathologists regarding COD were analysed to look at the effectiveness of PMCT in determining COD during a pandemic. Analysis showed that 78.7% (133) of cases reported by forensic radiologists concurred with the COD certified by forensic pathologists. Of these cases, 85 (63.9%) had undergone only external examination and real-time reverse transcriptase polymerase chain reaction (rRT-PCR) COVID-19 testing, meaning that imaging was the sole method used to determine the COD besides history from available medical records and the investigating police officer. PMCT can be used as a complement to medicolegal autopsies in pandemic contexts, as it provides significant information on the possible COD without jeopardising the safety of mortuary health care workers.

Accuracy of forensic pathologists in incorporating post-mortem CT (PMCT) in forensic death investigation.

Post-mortem computed tomography (PMCT) is now performed routinely in some medical examiner's offices, and the images are typically interpreted by forensic pathologists. In this study, the question of whether pathologists appropriately identify significant PMCT findings and incorporate them into the death investigation report and the cause and manner of death (COD and MOD) statements was addressed. We retrospectively reviewed 200 cases where PMCT was performed. The cases were divided into four categories: (1) full autopsy without radiology consultation (n=77), (2) external exam without radiology consultation (n=79), (3) full autopsy with radiology consultation (n=26), (4) external exam with radiology consultation (n=18). A radiologist (not the consult radiologist) read the PMCT images, and a pathologist (not the case pathologist) reviewed the case pathologist's post-mortem examination report in tandem to determine any PMCT findings omitted from the report. Omitted findings were classified into error types according to a modified Goldman classification including Major 1: Unrecognized fatal injury or pathology that would change COD and/or MOD, and Major 2: Unrecognized fatal injury or pathology that would not change COD and/or MOD. A total of 13 Major errors were identified (6.5%), and none definitively changed the MOD. All four Major-1 errors which could change the COD were found in Category 2. Of 9 Major-2 errors, 2 occurred in Category 1, 6 occurred in Category 2, and 1 occurred in Category 4. In conclusion, forensic pathologists who routinely utilize computed tomography (CT) interpret CT images well enough to reliably certify the COD and MOD.

Pediatric push pin aspiration: clinical, radiologic, and pathologic correlation — case report

BackgroundAspiration of foreign bodies is not uncommon in the pediatric setting, and the consideration and recognition of an aspiration event are vital to prompt management. Pointed and sharp-edged foreign bodies have the potential to lodge in the airway and increase the difficulty of identification and removal. Here, we describe a fatal aspiration of a push pin that was unrecognized prior to death.MethodsReview of police and medical records was completed prior to postmortem CT imaging and full pediatric autopsy with high resolution photography.Case presentationA 15-month-old boy was playing at home when he acutely vomited and then became unresponsive. Paramedic and hospital physicians performed pediatric CPR protocols, including intubation, without success. Postmortem radiographic imaging revealed a metallic foreign body at the level of the larynx. Autopsy demonstrated a push pin fully occluding the trachea at the level of the vocal cords.ConclusionsThe diagnosis of aspirated FBs may be elusive, and clinicians and autopsy pathologists ought to be mindful that children with FBs may have atypical presentations. Use of postmortem radiologic imaging can assist in the diagnosis and allow for a targeted autopsy approach to best visualize the offending foreign body.

Comparison of findings identified at traditional invasive autopsy and postmortem computed tomography in suicidal hangings

Cases of suicidal hanging are a common death referred for medico-legal autopsy throughout the world. Although some advocate using postmortem computed tomography (PMCT) without traditional invasive autopsy (TIA) to investigate such deaths, others reject this approach. There is currently limited evidence to guide practice. In this context, the TIA reports and PMCT images of 50 cases of suspected suicidal hanging during an 11-month period were reviewed. The reviewers were blinded to the findings of the other modality. A Cohen’s Kappa coefficient (K) was calculated to assess agreement between TIA and PMCT across a range of pertinent findings. This analysis demonstrated perfect agreement for identification of a ligature (K = 1.00) and a strong level of agreement for identification of a ligature suspension point (K = 0.832) but only a minimal level of agreement for overall ligature mark (K = 0.223). PMCT demonstrated a weak level of agreement for fractures of hyoid bone (K = 0.555) and thyroid cartilage (K = 0.538). Three probable fractures not identified at TIA were identified on PMCT. TIA was shown to be superior in the identification of intramuscular and laryngeal fracture–related haemorrhage/bruising whereas PMCT was superior to TIA in identifying body gas deposition. There was overall good correlation between the natural disease and trauma identified elsewhere in the body during the TIA and PMCT. The study demonstrates that PMCT can assist the investigation of suspected suicidal hangings. However, the accuracy of many findings is limited, and if it is used as an alternative to the TIA, potentially pertinent findings, such as fractures of the laryngeal cartilages, could be missed.

Post-Mortem Computed Tomography Pulmonary Findings in Harbor Porpoises (Phocoena phocoena).

Simple SummaryThe use of cross-sectional imaging techniques to examine the cause of death and health status of deceased animals is increasing in both veterinary and wildlife conservation programs, including species of whales and dolphins. Lung disease is common in harbor porpoises (Phocoena phocoena), a small whale species that regularly washes up on the coast in North Sea-bordering countries. This study aimed to describe lung changes visible in computed tomographic (CT) images of recently deceased harbor porpoises before pathological dissection was performed, including comparison of these two examination methods. Despite frequently visible signs of body decomposition, several lung abnormalities (collapsed lung, fluid in the airways, lung mineralization) were more often seen on the CT images. In general, lung changes could be described in more detail compared to gross dissection. CT images of lungs of recently deceased harbor porpoises can therefore be used to guide gross dissection, leading to more specific findings and potentially a more complete understanding of the circumstances leading to the death of the porpoise, assessment of the population, and ultimately, ecosystem health.The application of whole-body post-mortem computed tomography (PMCT) in veterinary and wildlife post-mortem research programs is advancing. A high incidence of pulmonary pathology is reported in the harbor porpoise (Phocoena phocoena). In this study, the value of PMCT focused on pulmonary assessment is evaluated. The objectives of this study were to describe pulmonary changes as well as autolytic features detected by PMCT examination and to compare those findings with conventional necropsy. Retrospective evaluation of whole-body PMCT images of 46 relatively fresh harbor porpoises and corresponding conventional necropsy reports was carried out, with a special focus on the respiratory tract. Common pulmonary PMCT findings included: moderate (24/46) to severe (19/46) increased pulmonary soft tissue attenuation, severe parasite burden (17/46), bronchial wall thickening (30/46), and mild autolysis (26/46). Compared to conventional necropsy, PMCT more frequently identified pneumothorax (5/46 vs. none), tracheal content (26/46 vs. 7/46), and macroscopic pulmonary mineralization (23/46 vs. 11/46), and provided more information of the distribution of pulmonary changes. These results indicate that PMCT adds information on pulmonary assessment and is a promising complementary technique for necropsy, despite the frequent presence of mild autolytic features.

A post-mortem computed tomography imaging method for predicting the anteroposterior and superoinferior positions of the Japanese adult eyeball in the orbit

: Predicting the position of the human eyeball is particularly difficult in facial approximation. While prediction methods for eyeball position based on skull features have been proposed in Caucasians, this study aimed to establish a method using anatomical landmarks on Mongoloid skulls. : Using post-mortem computed tomography (PMCT) images, we plotted landmarks on the skull and soft tissues of 146 Japanese adult cadavers and recorded the coordinates using CT image viewer software (OSIRIX MD, Pixmeo). We measured the distances between these landmarks and processed the data statistically in Microsoft Excel®>. : The results showed significant differences for many variables compared to previous guidelines and measurements, suggesting the need for a prediction method based on ancestry. We identified factors such as sex, body mass index, and age that influenced eyeball location. Next, we estimated the prediction standards of the globe position from the measurements obtained in this study and applied them to unidentified cadavers. The correlation coefficient was 0.737 in the anteroposterior direction and 0.291 in the superoinferior direction. The small correlation coefficient for eye protrusion was likely based on the lack of power, owing to the limited number of samples in the database. : Important factors in predicting facial features, such as sex, age, and ancestry, contributed to more accurate facial approximation. Future analyses using a larger database to establish more accurate prediction guidelines are necessary.

Virtopsy in a case of intrathoracic dislocation of the head of the humerus: Does this imply an active defense to fall from great height?

• Rare injury detail of intrathoracic humeral head in a case of fall from great height • Context of wilful arm extension in light of surgical / clinical case reports makes this a forensically relevant aspect to consider with regard to the victim of the fall being conscious at time of fall • Post-mortem CT images showing findings in original anatomic context To cause a humeral head to be forced into the thoracic cavity, break off, and remain there, a number of requirements may have to be met – including (possibly active) extension of the arm, dislocation of the shoulder, and subsequent impaling of the humerus into the thoracic cavity. The authors describe a case involving an apparent accidental or suicidal fall from a great height. The humeral head resided in the right thoracic cavity, and the many other fall-related injuries included rib fractures, pulmonary contusions, and pneumatoceles, as well as external injuries with abrasions and bruising of the right palm and elbow. A brief review of the literature revealed that active arm extension may be considered as a plausible prerequisite for the humeral head to break off within the rib cage. Therefore, an intrathoracic humeral head may have to be considered as a result of active arm extension during falls from a great height.

Stature estimation of Malaysians using post-mortem computed tomography images of the spine

Background Stature estimation is important in medical investigations to identify victims and is most accurate using anatomical methods utilizing the entire skeleton. However, in cases of mass fatalities, it has been calculated using regression analysis formulas of different body parts. Radiology especially post-mortem computed tomography (PMCT) is increasingly being used in victim identification as it is non- invasive and allows for multi planar reconstruction. Methods This study aims to generate stature estimation formulae using regression analysis of the vertebral column incorporating population that form the Malaysian ancestry i.e. Malay, Chinese and Indian using PMCT. This was a retrospective study involving 115 subjects who had a PMCT. Subjects consisted of Malaysian males and females (92 males and 23 females) aged 18–70 years. Cervical length (CL), thoracic length (TL), lumbar length and the whole spine length (WSL) incorporating cervical, thoracic and lumbar length were compared against cadaveric length. Results Whole spine length had the highest correlation coefficient of 0.570 and showed highest correlation with cadaveric length among female subjects compared to males. Whole spine length amongst the Malay was the highest followed by the Chinese and Indian ethnic groups (r = 0.671, 0.629, 0.402). Conclusion Our study concluded that the use of WSL from PMCT images can be used for body height estimation amongst Malaysians. This study has also successfully generated population-specific database for Malaysian experts to perform stature estimation using measurements of the vertebral column.

Potential for personal identification using the volume of the mastoid air cells extracted from postmortem computed tomographic images

This study revealed the usefulness of volumetric analysis of mastoid air cells (MACs) extracted from postmortem computed tomography (PMCT) images in characterizing individuals. To characterize deceased persons, the MACs volumes of 61 Japanese PMCT images were measured after thresholding in Hounsfield units and based on the number of voxels on the right and left sides and the voxel size for each person. The volume differences between the right and left MACs and sex were examined. Although there were no obvious volume differences between males and females, the order of sizes on the two sides varied for each person. Moreover, deceased persons could be roughly classified using the total volume of MACs. Deceased persons with similar total volumes could be distinguished further by comparing the ratio of volumes in bilateral MACs. Although the identification process is dependent on samples and different sizes of bilateral MACs, our pilot study indicated that 81.9% (50/61) of deceased persons could be distinguished. In conclusion, volumetric analysis of MACs measured using PMCT imaging has the potential to identify individuals and reduce the number of candidates.

Early postmortem changes in the pulmonary artery and veins: An antemortem and postmortem computed tomography study

• Postmortem changes in the pulmonary artery and veins were unclear. • The diameter of the pulmonary artery and veins was measured at five points both on the antemortem and postmortem CT of the same patient. Two patient groups were enrolled: the control group and the died-of-congestive heart failure group. • In both groups, the main pulmonary artery diameter decreased after death. • Congestive heart failure caused a greater decrease in pulmonary vein diameter compared to the control group. To compare the diameter of pulmonary vessels on antemortem (AMCT) and postmortem computed tomography (PMCT). This retrospective case–control study included 641 patients who underwent AMCT within 30 days before death, died in the hospital, and underwent PMCT and conventional autopsy, as a reference standard, soon after death between 2009 and 2020 at a university hospital. The control group comprised 8 patients without lung and pulmonary vessel abnormalities, whereas the heart failure group comprised 16 patients who died of congestive heart failure. The diameters of the main pulmonary artery and bilateral superior and inferior pulmonary veins were measured on AMCT and PMCT images and statistically analyzed (240 vessels in total). In both groups, PMCT resulted in significantly smaller main pulmonary artery diameters compared to AMCT. The control group had greater pulmonary vein diameters compared to the heart failure group after death, although the difference did not reach statistical significance. Comparison between the groups revealed that the heart failure group had significantly greater tendency for postmortem decrease in the pulmonary vein diameters compared to the control group. Our findings showed that the main pulmonary artery diameter decreases after death. Moreover, patients who died of congestive heart failure had a greater tendency for decreased pulmonary vein diameter compared to those who died without cardiopulmonary abnormalities. Five measuring points of the pulmonary vessels.