Akihito Usui

Herein, we present a case involving a markedly decomposed body in which non-contrast postmortem computed tomography (PMCT) demonstrated long-segment right coronary artery ectasia with focal aneurysmal dilatation. A man estimated to be in his 30s was found dead 12 days after he had last been confirmed alive. PMCT showed extensive decomposition-related gas and identified a conspicuously dilated segment along the anatomical course of the right coronary artery. Curved planar reformations showed that the dilated segment measured approximately 106 mm in length. Autopsy confirmed focal aneurysmal dilatation of the right coronary artery and cardiomegaly. Dark red intraluminal material was present in one cross-section, but advanced decomposition and autolysis precluded confirmation of antemortem thrombosis or acute myocardial infarction. This case illustrates the value and limitations of non-contrast PMCT for documenting coronary morphology in markedly decomposed bodies.

Falling trees and large branches can result in severe blunt trauma; however, detailed correlations between postmortem computed tomography (PMCT) and forensic autopsy findings in such deaths remain limited. We retrospectively analysed eight consecutive deaths occurring between 2012 and 2025 in which impact or compression by a tree trunk or large branch constituted the primary traumatic event and in which both PMCT and complete forensic autopsy were performed. Thin-slice PMCT of the head and trunk was obtained using standard brain, soft-tissue, lung, and bone windows, supplemented by a gas-optimised thoracic setting. Scene information, PMCT, and autopsy findings were integrated to determine the primary mechanism of death and to compare intracranial, thoracoabdominal, skeletal, and asphyxial injuries. Four lethal mechanisms were identified: instantly fatal head or brainstem injury (n = 2), haemorrhagic shock without cardiac rupture (n = 2), traumatic shock with cardiac rupture and/or aortic injury (n = 2), and asphyxia due to smothering or thoracic compression (n = 2). PMCT demonstrated complex fractures of the ribs, scapulae, spine, and pelvis, as well as haemothorax, haemoperitoneum, pneumomediastinum, and pre-existing coronary artery calcification, and suggested aortic injury in one case. However, brainstem lesions, precise sites of cardiac and aortic rupture, and low-contrast parenchymal injuries were identified only at autopsy. These results suggest that PMCT is valuable for delineating global injury patterns and high-energy marker lesions in falling-tree deaths, whereas full forensic autopsy remains essential for establishing the exact mechanism of death.

Prolonged immersion in a reheated bathtub can cause extensive thermal alteration and produce intracranial findings that mimic traumatic lesions on postmortem computed tomography (PMCT). Here, we report a bath‐related fatality in a woman in her late 60s in which PMCT demonstrated a crescent‐shaped epidural collection along the right parietal convexity. The collection exhibited layered components, consisting of a fat‐attenuation upper layer and a dependent low‐attenuation layer with a small amount of gas. PMCT also demonstrated diffuse bilateral ground‐glass opacities, bilateral pleural effusions, and left pneumothorax, as well as fluid accumulation in the paranasal sinuses and airway fluid with foam. At autopsy, extensive epidermal stripping and blistering with heat rigor were observed, and red frothy fluid was present within the airway. Autopsy revealed a brick‐colored epidural deposit (approximately 15 g) without skull fracture, consistent with heat‐coagulated blood. Toxicological analysis detected triazolam and mirtazapine in the blood. Drowning was considered highly likely; however, definitive confirmation was limited by severe systemic thermal alteration. This case highlights a forensic diagnostic pitfall in which heat hematoma‐like epidural changes following prolonged hot‐water immersion may mimic traumatic epidural hematoma on PMCT, underscoring the importance of integrating scene information, toxicology, PMCT, and autopsy findings.

MnGdxFe2-xO4 nanoparticles ( ${x} =0$ , 0.05, 0.10) encapsulated in amorphous SiO2 were prepared by doping with a small amount of Gd ions, and their magnetic relaxation and magnetic resonance (MR) effects were investigated. The samples were prepared by wet mixing of metal chlorides and sodium metasilicate solutions, and the particle size was controlled to 18 nm by adjusting the annealing temperature. ${T} _{1}$ and ${T} _{2}$ relaxation measurements were performed by spin-echo method and MR signals were measured. All samples showed a shortening effect of ${T} _{2}$ relaxation. These phenomena would be attributed to the strong effect of the magnetic moment of Gd, which has a maximum of seven unpaired electrons in the $4{f}$ orbitals on the protons. A dominant shortening effect was also observed at ${T} _{1}$ signals. The same sample was examined to see if it would function as a reagent for hyperthermia treatment. Temperature rises in an ac magnetic field and in vitro experiments using human breast cancer cells were carried out. As a result, a superior hyperthermia effect was observed, and these samples are expected to be an agent with theranostic function in the future.

Background: Sternal foramina are congenital anomalies arising from incomplete fusion of sternal ossification centers. They are often clinically silent but can pose risks during sternal procedures because of their proximity to critical mediastinal structures. Large‐scale postmortem computed tomography (CT) studies of their prevalence in Japanese populations are limited, and their developmental origins remain elusive. We aimed to investigate the development, prevalence, and anatomical characteristics of sternal foramina in a large Japanese cohort using postmortem CT. Methods: We retrospectively reviewed postmortem CT scans from 1503 adults (1021 males, 482 females; age range: 20–96 years) and 92 pediatric cases (age range: 0–8 years). In adults, we assessed prevalence, sex distribution, location, diameter, and adjacent structures. In pediatrics, ossification patterns of the third and fourth sternebral segments were evaluated to explore developmental contributions to foramen formation. Results: Sternal foramina were present in 3.7% of adults. They were more frequent in males (4.3%) than in females (2.5%), although the difference was insignificant. Most foramina were located at the level of the fifth costal notch and overlaid the pericardium or lung in 72% of evaluable cases. The median diameter was 4.5 mm. In pediatric cases, 11 (12%) exhibited lower‐sternebral ossification‐center patterns that could form sternal foramina, supporting a developmental origin. An estimated 31% of these patterns may persist into adulthood with unfused segments. Conclusion: Sternal foramina occurred in 3.7% of adults and were often situated over vital structures, posing procedural risks. Among pediatrics, ossification patterns that may impede fusion—defined as horizontal two‐center or ≥ 3 center configurations—were present in 12%, and approximately 31% of these patterns appear to persist into adulthood as sternal foramina. These findings support a developmental basis for sternal foramina and emphasize the importance of recognizing them during imaging and procedural planning.

This study attempts to classify ear morphology for human identification in forensic investigations by distinguishing between the upper auricle and lobule areas. A three-dimensional homologous model of the ear was created using 414 ear images of males aged 17–93 years reconstructed from computed tomography scans of forensic autopsy cases. Morphological changes were visualized using principal component analysis and areas of significant individual differences within the entire ear were identified. The classification criterion images for the upper auricle (ten images) and lobule (12 images) were developed by combining multiple principal component values: components 1–5 for the upper auricle and 1–6 for the lobule. Three-dimensional ear images of the upper auricle and lobule areas from 414 subjects were categorized using a measurement method based on the minimum distance between 5,507 corresponding points. The results indicate the applicability of the criterion images for the morphological classification of ears in this study.