Researchers at the Department of Forensic Medicine and Toxicology at the All India Institute of Medical Sciences in New Delhi, together with a colleague from the Department of Biochemistry at Vardhman Mahavir Medical College and Safdarjung Hospital, analyzed 247 autopsy-confirmed natural deaths. The team, led by Gokul G., Abilash S., and Abhishek Yadav under the supervision of Sudhir K. Gupta, deliberately excluded cases with trauma, visible putrefaction, or invasive airway management. Each of those exclusions matters: trauma can introduce air into vessels artificially, putrefaction generates gas that swamps any earlier signal, and procedures such as intubation or resuscitation can push gas into the circulation. By stripping away these artifacts, the researchers could study intravascular gas in its cleanest possible context, the early postmortem interval in bodies that died naturally.

The technical approach was straightforward but rigorous. On pre-autopsy PMCT scans, the team graded intravascular gas on a scale from zero to three in three vascular territories: the hepatic vessels serving the liver, the coronary vessels supplying the heart, and the cerebral vessels of the brain. Grading rather than simply noting presence or absence allowed the researchers to test whether the amount of gas increased with time since death, as a decomposition-driven process would predict. Statistical analyses then evaluated two distinct questions: whether gas grade correlated with the postmortem interval, and whether gas in one vascular system was associated with gas in the others.

The results were striking. Gas appeared frequently in the hepatic vasculature, present in 50.6 percent of cases, and in the coronary vessels, present in 51.4 percent of cases. But the cerebral vasculature told a very different story: gas was found there in only 9.7 percent of cases. This asymmetry alone is informative. If intravascular gas were simply a uniform decomposition product diffusing through the entire circulatory system, one might expect it to appear more evenly across territories. Instead, the liver and heart vessels filled with gas roughly half the time while the brain’s vessels almost never did during the early postmortem period.

Even more consequential was what the correlation analysis revealed, or rather failed to reveal. Across all three vascular territories, there was no significant linear correlation between gas grade and the postmortem interval. In practical terms, this means that the amount of gas visible on PMCT cannot serve as a reliable clock for estimating time since death, at least during the early postmortem window this study examined. That finding challenges a line of research that has sought to use postmortem gas volume changes for postmortem interval estimation, including animal-model studies and investigations linking gas detected on PMCT with hypostasis and the postmortem interval. The new data suggest that during the critical early hours, gas accumulation does not progress in a predictable linear fashion that forensic investigators could convert into a time estimate.

But if gas is not a clock, what is it? The answer, according to the study, lies in its distribution pattern. The researchers found a strong systemic association between the hepatic and coronary systems, with a correlation coefficient of rho equal to 0.765. In other words, when gas appeared in the liver’s vessels, it very often appeared in the heart’s vessels as well, and vice versa. The two systems filled together, suggesting a shared underlying mechanism rather than independent local processes. This tight coupling between the portal venous system of the liver and the coronary circulation echoes earlier observations, including PMCT demonstrations of the relationship between gastrointestinal distension and hepatic portal venous gas, and analyses of cardiovascular gas in non-traumatic deaths.

The cerebral vasculature added a final layer of pattern. Cerebral gas was observed only in conjunction with hepatic and coronary gas, and isolated cerebral gas was never identified in the entire sample. The brain’s vessels, in effect, only filled when the liver and heart vessels had already filled. This hierarchical pattern, hepatic and coronary gas common and coupled, cerebral gas rare and dependent, gives forensic radiologists a reproducible systemic signature for early postmortem intravascular gas in natural deaths.

That signature has immediate practical value. When a PMCT scan shows gas distributed in exactly this way, common in the hepatic and coronary territories, rare in the cerebral circulation, and never isolated in the brain, the finding is consistent with a normal postmortem process in a natural death. Conversely, a deviation from the pattern, specifically isolated cerebral gas on PMCT, stands out as anomalous. The authors hypothesize that such findings may indicate antemortem etiologies, such as air embolism or barotrauma, in which gas entered the circulation before death and became trapped in the cerebral vasculature. This hypothesis requires future validation, but it offers a concrete, testable rule for a distinction that has long troubled forensic interpretation. Prior work has grappled with exactly this problem, including case reports differentiating putrefactive gas from air embolism in traumatic carotid-jugular arteriovenous fistula, scoping reviews of medico-legal interpretations of gas on postmortem CT, and evaluations of gas at PMCT in non-putrefied trauma and non-trauma cases. Intracranial gas on postmortem CT in traumatic cases has been particularly contested in medico-legal opinions, and gas analysis has even been used alongside postmortem imaging to diagnose causes of death through compositional analysis of the gas itself.

The study’s design choices strengthen its conclusions. Ethical clearance was granted by the AIIMS Institutional Ethics Committee, informed consent was obtained from the legally acceptable representative of each deceased person, and the work was conducted in accordance with the Declaration of Helsinki. The retrospective observational design, applied to a large consecutive sample of natural deaths with strict exclusion criteria, minimizes the confounding that has plagued smaller studies. The authors note no competing interests and no external funding, and the data generated for the study is available from the corresponding author on reasonable request.

For the growing field of forensic radiology, the implications are considerable. PMCT has become a standard component of virtual autopsy workflows since the early feasibility studies of postmortem multislice CT and MRI, and every scan raises the interpretive question of what intravascular gas means. This study provides a data-driven answer for natural deaths: during the early postmortem interval, intravascular gas follows a predictable systemic association across the hepatic, coronary, and cerebral vascular systems, and it does not track the postmortem interval in any usable linear way. The pattern itself, rather than the quantity of gas, becomes the diagnostic signal. If future validation confirms the authors’ hypothesis, isolated cerebral gas on PMCT could become a recognized indicator of antemortem air embolism or barotrauma, transforming a frequent and ambiguous finding into a targeted clue for cause-of-death investigation. In the meantime, the study gives forensic pathologists something they have lacked: a reproducible baseline for one of postmortem imaging’s most common sights.

Subject of Research: Distribution of postmortem intravascular gas on PMCT in natural deaths

Article Title: Distribution patterns of postmortem intravascular gas on PMCT in natural deaths

Article References: G., G., S., A., Yadav, A., Kumar, P., K., K., & Gupta, S. K. (2026). Distribution patterns of postmortem intravascular gas on PMCT in natural deaths. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04041-3

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04041-3

Keywords: PMCT, postmortem intravascular gas, forensic radiology, postmortem interval, air embolism, virtual autopsy, Distribution, patterns, postmortem, intravascular, natural, deaths

The research, led by Oguzhan Ekizoglu together with Marine Dario, Maxime Pastor, Catherine Cyteval, and Laurent Martrille, focused on a bone that has been comparatively neglected in the MRI-based age estimation literature: the proximal humerus, the ball-shaped top of the upper arm bone. While the hand-wrist region and the knee have been extensively mapped with MRI for forensic purposes, the shoulder has received far less systematic attention, particularly in Western European populations. The team retrospectively analyzed 346 shoulder MRI examinations drawn from a French cohort spanning the ages of 7.18 to 33.82 years, comprising 204 males and 142 females. Because the scans had been acquired for clinical reasons and were fully anonymized, the ethics committee of CHU Montpellier approved the study and waived the need for individual informed consent, an approach consistent with the Declaration of Helsinki.

The technical backbone of the study is the combined Schmeling–Kellinghaus staging system, a widely used framework originally developed for the medial end of the collarbone. In this system, ossification of the epiphysis, the secondary growth center that fuses to the main bone shaft after puberty, is graded in discrete stages, from an entirely cartilaginous growth plate through progressive partial fusion to complete union, with an optional subdivision for the earliest signs of fusion. On T1-weighted MRI sequences, the developing bone and the cartilaginous plate between epiphysis and metaphysis produce distinct signal intensities, allowing a trained observer to assign each shoulder to a stage. Two independent raters, blinded to each subject’s age and sex, staged all 346 scans, providing a direct test of how reproducible the method is when applied to the humeral head.

The results were strikingly consistent. The correlation between chronological age and ossification stage was strong and statistically significant across the whole sample, with a Spearman’s rank correlation coefficient of 0.878, and nearly identical values of 0.880 in males and 0.878 in females, all with p-values below 0.001. In practical terms, this means that as the humeral epiphysis progresses through its developmental stages, age increases in a tight, predictable relationship, and that this relationship holds equally well for both sexes. Statistical testing with the Mann–Whitney U method found no significant difference between males and females in the ages associated with any given stage, a finding that simplifies the application of the system, since a single set of stage descriptions may suffice for both sexes in this population.

Reliability, the measure of whether different observers reach the same conclusion from the same image, was equally impressive. Cohen’s kappa, a statistic that quantifies agreement beyond what would be expected by chance, reached 0.911 within observers rating their own scans twice and 0.890 between the two independent raters. Values above 0.8 are conventionally considered to indicate very good agreement, and these figures place the proximal humerus staging on par with, or better than, many established forensic imaging indicators. For a method that might one day inform legal decisions with life-changing consequences, this level of observer agreement is not a technical nicety but an essential prerequisite, because inconsistent readings between experts would undermine the credibility of any age estimate offered in court.

The most legally consequential finding concerns the age of majority, the threshold at 18 years that separates minors from adults in most jurisdictions. In this cohort, the youngest individual showing stage 4, defined by the presence of a visible epiphyseal scar after fusion, was 18.33 years in males and 18.06 years in females. In other words, once the epiphyseal scar is visible on the proximal humerus, the data suggest the person has very likely passed their eighteenth birthday. Notably, stage 5, the final stage of the amplified scheme, was never observed despite the cohort including individuals up to nearly 34 years of age, an observation the authors interpret in light of the persistent visibility of the epiphyseal scar in adult shoulders and the anatomical characteristics of trabecular bone in this region.

Beyond the conventional minimum-age approach, the team applied an ordinal probit transition analysis, a statistical framework borrowed from paleodemography that models the probability of moving from one ossification stage to the next as a function of age. Rather than relying on the single youngest individual observed at a stage, a figure that is highly sensitive to how many older or younger people happen to be in the sample, transition analysis yields sex-specific ages at which the probability of progression to the next stage reaches 50 percent. This provides a more statistically robust characterization of the timing of skeletal maturation and has been increasingly advocated in forensic age research, including recent work on third molars and other skeletal indicators. The authors are careful, however, to stress that both minimum-age and transition-age estimates derived from any single cohort should not be applied as forensic thresholds without independent, population-specific validation, a caution that reflects the well-documented variation in skeletal maturation across populations and socioeconomic conditions.

Perhaps the most original contribution of the study is the description of a previously unreported interpretive pitfall. The authors identified a trabecular hypointense pattern, a dark appearance of the internal bone architecture on T1-weighted images, that can potentially mimic a persistent gap between the epiphysis and the metaphysis, the appearance that would normally indicate an unfused, and therefore juvenile, growth plate. Mistaking this normal variant for an open growth plate could lead an examiner to underestimate a person’s age, with serious implications in asylum or criminal proceedings. The paper includes recommendations for recognizing this pattern, underscoring that even a highly reliable staging system depends on the examiner’s ability to distinguish true developmental landmarks from imaging artifacts and anatomical variants of the cancellous bone in the proximal humerus.

The broader context of this work is a slow but decisive shift in forensic practice. European radiation protection directives and international basic safety standards from bodies such as the International Atomic Energy Agency have sharpened the ethical and legal scrutiny applied to X-ray-based age assessments in healthy young people, pushing researchers toward MRI as a non-ionizing alternative. Previous MRI studies of the proximal humeral epiphysis, including earlier work by Ekizoglu and colleagues on Turkish cohorts and studies from China and Turkey using both 1.5 and 3.0 Tesla scanners, have demonstrated the promise of the approach, but population-specific data remained sparse for Western Europe. By extending the combined Schmeling–Kellinghaus system to a French cohort for the first time, the Montpellier team has filled an important geographic gap and shown that the staging framework travels well across populations, at least in terms of correlation strength and observer reliability.

What remains before shoulder MRI can enter routine forensic use is a matter of validation and standardization rather than proof of concept. Large, independently collected cohorts from different populations will be needed to confirm the minimum ages and transition probabilities reported here, and the newly described trabecular pitfall will need to be characterized across scanner types and imaging protocols. Cost and scanner availability also remain practical constraints, since MRI is more expensive and less widely accessible than plain radiography. Nevertheless, the study offers a compelling vision of the field’s future: a radiation-free, highly reproducible, and anatomically well-characterized method for answering one of forensic science’s most sensitive questions. For the hundreds of thousands of young people whose ages are contested each year in legal systems worldwide, the humeral head, imaged safely with magnets rather than X-rays, may soon become a key witness.

Subject of Research: Non-ionizing forensic age estimation using T1-weighted MRI of the proximal humeral epiphysis in a French cohort

Article Title: T1-Weighted MRI of the proximal humerus: Toward a non-ionizing approach to forensic age estimation in a French cohort

Article References: Ekizoglu, O., Dario, M., Pastor, M., Cyteval, C., & Martrille, L. (2026). T1-Weighted MRI of the proximal humerus: Toward a non-ionizing approach to forensic age estimation in a French cohort. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03996-7

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03996-7

Keywords: forensic age estimation, MRI, proximal humerus, epiphyseal fusion, Schmeling-Kellinghaus staging, age of majority, transition analysis, non-ionizing imaging, forensic medicine, immigration, radiation protection, French cohort

The research, led by Alperen Tekin and colleagues at Istanbul Medeniyet University, addresses a persistent challenge in forensic anthropology. When investigators recover skeletal remains, estimating sex is one of the first and most important steps, because it narrows the pool of missing persons and shapes every subsequent analysis of age, stature, and ancestry. The most reliable methods rely on the pelvis and skull, but these bones are frequently missing, fragmented, or damaged in disaster scenes, fires, and archaeological contexts. Vertebrae, which are dense and often survive, have therefore attracted growing attention as alternative sex indicators, and the second cervical vertebra, known as the axis or C2, has emerged as a particularly promising candidate.

What makes the new study distinctive is its source of imaging data. Cone-beam computed tomography, or CBCT, is a low-dose scanning technology used routinely in dentistry and maxillofacial radiology, and the axis vertebra falls within the field of view of many head-and-neck CBCT examinations. This means that vast archives of existing clinical scans, acquired for entirely unrelated dental reasons, could in principle be mined for forensic information without exposing anyone to additional radiation. The researchers exploited this opportunity by retrospectively analyzing 140 adult CBCT examinations, 68 from female patients and 72 from male patients, all acquired on a single scanner under homogeneous imaging conditions.

Rather than measuring the bone manually with calipers, as traditional morphometric studies do, the team turned to radiomics, a computational approach that converts medical images into hundreds of quantitative features. Radiomics captures characteristics that the human eye cannot reliably assess, including the statistical distribution of gray values, the coarseness and uniformity of bone texture, and the precise three-dimensional shape of the segmented structure. From each scan, the researchers extracted 107 original-image radiomic features from two different regions of interest: the entire second cervical vertebra, and the odontoid process alone, the tooth-like projection that rises from the vertebral body and allows the head to rotate.

The central question was methodological as much as forensic. If a forensic team only has access to the odontoid process, perhaps because the rest of the vertebra is damaged or outside the scan volume, does segmenting just that smaller structure sacrifice the discriminative information contained in the whole bone? To find out, the researchers built paired prediction models for each region of interest, using regularized machine learning algorithms, including least absolute shrinkage and selection operator, or LASSO, regression and elastic-net regression, both of which are designed to handle datasets where the number of features is large relative to the number of samples.

The results, validated through a rigorous internal testing framework, were strikingly consistent. Across 100 repeated paired validations with a balanced 80/20 train-test split, the mean area under the receiver operating characteristic curve, or AUC, reached 0.929 for the combined whole-C2 models, while the odontoid-only models achieved mean AUCs of 0.924 for texture-only features, 0.918 for combined LASSO models, and 0.905 for combined elastic-net models. An AUC of 0.5 would indicate performance no better than a coin flip, while 1.0 represents perfect discrimination, so values above 0.9 indicate strong internal classification ability. Five-fold nested cross-validation, a more conservative scheme that guards against information leaking from the test data into model training, produced AUCs of 0.918 for the whole-C2 combined LASSO model and 0.914 for the odontoid-only equivalent, confirming that the advantage of the whole vertebra was marginal at best.

The team also took deliberate steps to guard against the inflated performance estimates that have plagued much of the radiomics literature. All preprocessing steps were fitted exclusively on the training set, label-permutation testing was used to verify that the models were genuinely learning signal rather than noise, and the permutation null distributions were centered near 0.50, with a permutation p-value of 0.003 for both regions of interest. The authors were candid about the limits of their most eye-catching numbers: the highest AUCs observed on the primary test split, which ranged from 0.985 to 0.995, were derived from only 28 test subjects and were explicitly interpreted as optimistic estimates rather than realistic expectations of casework performance.

Perhaps the most consequential finding is that the odontoid process alone, a structure smaller than a fingertip, carries nearly as much sex-related information as the entire vertebra. The whole-C2 region retained more shape information, which makes anatomical sense given that the axis vertebra shows well-documented sexual dimorphism in its overall dimensions, but the texture features computed from the odontoid process alone performed on a par with the full-bone models. For forensic practice, this matters because the odontoid process is compact, anatomically well-defined, and easy to segment, and because it may be the only part of the vertebra preserved or captured in certain imaging scenarios. Previous studies had already shown that odontoid volume and morphometry differ between sexes, and the new results suggest that subtle internal bone texture adds a further layer of discriminative signal.

At the same time, the researchers are careful not to oversell the approach, and their caveats deserve as much attention as their headline numbers. The study was retrospective and single-device, meaning all scans came from one scanner and one institution under homogeneous imaging conditions, so the models have not yet faced the variability of different machines, scanning protocols, and populations. No external validation was performed, the reliability subsets used to assess feature reproducibility were too small to support comparative conclusions between the two regions of interest, and the biological meaning of many texture descriptors remains uncertain. High dimensionality and possible instability in feature selection further complicate interpretation, and the authors note that these limitations restrict the applicability of the models to real forensic casework for now.

Even with those caveats, the study represents a meaningful step toward a future in which routine dental scans, already acquired for millions of patients, double as a forensic resource. The work aligns with international standardization efforts such as the Image Biomarker Standardization Initiative and follows modern reporting frameworks for prediction models, signaling a maturing field that is increasingly aware of its own methodological pitfalls. If future multi-center studies can confirm that C2 radiomics generalizes across scanners and populations, forensic investigators may one day load an anonymous CBCT scan into software, segment a bone the size of a thumb, and receive a statistically grounded estimate of sex within seconds, turning an everyday dental image into a silent witness that helps put a name to the nameless.

Subject of Research: CBCT radiomics of the second cervical vertebra for forensic sex estimation

Article Title: Whole-axis versus odontoid process CBCT radiomics for forensic sex estimation: a retrospective paired-ROI model-development study

Article References: Tekin, A., Deveci, B., Tekin, G., & Ay, F. (2026). Whole-axis versus odontoid process CBCT radiomics for forensic sex estimation: a retrospective paired-ROI model-development study. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03999-4

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03999-4

Keywords: forensic anthropology, radiomics, cone-beam computed tomography, second cervical vertebra, odontoid process, sex estimation, machine learning, forensic radiology, LASSO, elastic net, bone texture analysis, International Journal of Legal Medicine

The work centers on the proximal tibial epiphysis, the growth plate at the upper end of the shinbone just below the knee joint. In 2018, Vieth and colleagues introduced an MRI-based staging system for this region that has since been validated by several independent research groups. The system’s most celebrated feature is its stage 6, which in male individuals was observed only after the eighteenth birthday, making it a potential marker of legal adulthood. Because magnetic resonance imaging involves no ionizing radiation, unlike computed tomography of the clavicles that is currently recommended when hand skeletal development is complete, MRI of the knee has been promoted as a more ethically acceptable tool for age estimation in living subjects.

Yet the earlier validation work by the same German group hinted at something else: stage 4, a mid-range category in which the growth plate is partially fused, might contain hidden structure. If the stage could be subdivided, perhaps the substages would align more closely with legally relevant ages such as fourteen, sixteen, or eighteen years. The new pilot study, led by Natia Chitavishvili of Jena University Hospital together with Daniel Wittschieber, Maria L. Hahnemann, and colleagues, set out to test that idea using a cohort of fifty-seven T1-weighted MRI examinations, twenty-four from males and thirty-three from females, all previously assigned to Vieth stage 4.

The technical logic behind the subclassification rests on a thin line of intermediate signal intensity that appears within the growth plate on T1-weighted turbo spin-echo images. This line represents the advancing front of bony fusion across the metaphysis. The researchers divided its extent relative to the total metaphyseal width into three categories: substage 4a when the line spans less than one-third of the width, substage 4b when it spans between one-third and two-thirds, and substage 4c when it exceeds two-thirds. Three experienced readers, a clinical radiologist, a pediatric radiologist, and a forensic medicine specialist, assessed only coronal images and evaluated every slice of the epiphysis, blinded to each subject’s age and sex throughout.

The results confirmed that every one of the fifty-seven cases could be placed into one of the three substages, demonstrating that the morphological criteria are workable in practice. Reliability statistics supported the scheme as well. Intra-observer agreement, measured when the first reader repeated all assessments two months after the initial consensus reading, yielded a Cohen’s kappa of 0.751, and inter-observer agreement between the first two readers reached 0.663. Under the conventional interpretation scale, both values fall within the range of good agreement, suggesting that different trained readers can apply the substages consistently.

The age data, however, tell a more complicated story. Among male subjects, the minimum ages at which substages 4a, 4b, and 4c were first observed were 15.45, 15.68, and 15.23 years respectively, meaning all three substages appeared only after the fourteenth birthday. Among females, the corresponding minimum ages were 12.64, 12.57, and 13.18 years. Statistically significant sex differences emerged for substages 4b and 4c, consistent with the well-documented pattern in which girls reach skeletal milestones roughly two years earlier than boys. In both sexes, substage 4c showed a particularly wide spread of chronological ages, weakening its value as a narrow age indicator.

What does this mean for the courtroom? The authors conclude that the substages may assist in verifying completion of the fourteenth year of life, at least in males, since no male in the cohort displayed any substage before age 15. But the crucial thresholds of sixteen and eighteen years, which drive decisions about criminal responsibility, asylum, and majority in many jurisdictions, could not be reliably verified with this subclassification. The broad age distributions, especially within substage 4c, mean that an individual at that substage could plausibly be anywhere within a multi-year window that straddles the legal boundaries that matter most.

The findings fit into a broader research landscape. Krämer and colleagues demonstrated as early as 2014 that substage assessment of the proximal tibial epiphysis by MRI was feasible, using an adapted system derived from the clavicle staging schemes of Schmeling and Kellinghaus, and reported minimum ages in comparable ranges. Ottow and colleagues expanded on that work in 2017 with 658 knee MRI scans from individuals aged twelve to twenty-four. More recently, Ekizoglu and colleagues introduced novel substages based on the Dedouit classification using MERGE sequences in 559 individuals, reporting minimum ages that likewise fell within similar age bands. Notably, the Dedouit approach has been criticized because it relies on absolute measurements of growth plate layer thickness, which may vary with body size and thereby introduce bias, whereas the Vieth system and its new substages rest on proportional, morphological criteria.

The authors are candid about the limitations of their pilot. With only fifty-seven cases, the numbers assigned to each substage were small, and substage 4a appeared in just five individuals, which limits the statistical power of the analysis. The retrospective design meant that scans came from different scanners at 1.5 and 3.0 Tesla with non-uniform clinical protocols, a heterogeneity that mirrors real-world practice but complicates precise morphological differentiation. The cohort, drawn from hospital records in Thuringia, was also predominantly Western Caucasian with a largely high socioeconomic background, raising questions about generalizability to the diverse populations that forensic age estimation actually serves. The researchers emphasize that the subclassification cannot currently be recommended for routine forensic practice without validation in larger, independent study populations.

Even so, the study adds a meaningful piece to the puzzle of skeletal maturation. It demonstrates that the intermediate signal line within the fusing tibial growth plate progresses in a graded, readable fashion, and it maps that progression onto chronological age with sex-specific reference values. Future prospective studies with standardized MRI protocols and larger multicenter cohorts may clarify whether the substages gain diagnostic value, particularly around the fourteenth-year threshold in males. For now, the message for forensic science is one of tempered expectation: the knee can speak about age, but its vocabulary at stage 4 remains too coarse to settle the sixteen- and eighteen-year questions that matter most in law.

Subject of Research: MRI-based subclassification of proximal tibial epiphysis ossification for forensic age estimation

Article Title: Subclassification of Vieth stage 4 in MRI of the proximal tibial epiphysis: a pilot study for forensic age estimation

Article References: Chitavishvili, N., Wittschieber, D., Papageorgiou, I., Malich, A., Mentzel, H.-J., & Hahnemann, M. L. (2026). Subclassification of Vieth stage 4 in MRI of the proximal tibial epiphysis: a pilot study for forensic age estimation. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03991-y

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03991-y

Keywords: forensic age estimation, MRI, proximal tibial epiphysis, Vieth staging, growth plate, ossification, knee joint, forensic radiology, radiation-free imaging, skeletal maturation, legal age thresholds, pilot study

The central premise of the field has not changed: imaging the dead can answer questions that matter enormously for the living. When a fetus dies in utero, when a newborn succumbs shortly after birth, or when a child dies unexpectedly, families and clinicians want answers. Conventional autopsy has long been the gold standard, but consent rates for full autopsy have fallen across much of the world, driven by religious and cultural concerns, emotional distress and simple unfamiliarity with the procedure. Less-invasive alternatives that use imaging — chiefly postmortem computed tomography and postmortem magnetic resonance imaging — promise a way to recover diagnostic information while respecting families’ wishes. That promise, the commentary argues, has come substantially closer to reality over the past ten years.

The turning point came in organizational form. In 2016, the European Society of Paediatric Radiology convened a dedicated postmortem imaging task force, building on an earlier questionnaire-based survey that had revealed how inconsistent practice was across European centres. That survey, published in 2014, documented wide variation in whether imaging was offered at all, which modalities were used, and how results were reported. The task force gave the field a focal point: a standing group of experts who could translate scattered research findings into practical, consensus-based guidance. The commentary’s authors, who have led much of this effort, frame the past decade as the story of what happened once that structure existed.

The most tangible products of that structure are the protocols. In 2019, a joint working group of the European Society of Paediatric Radiology and the International Society for Forensic Radiology and Imaging published the first standardized protocol for paediatric postmortem computed tomography, specifying how scans should be acquired in children of different sizes and ages. More recently, the task force has turned to magnetic resonance imaging, publishing a referral template for fetal and neonatal postmortem imaging in 2024, a full clinical protocol for fetal and neonatal postmortem MRI in 2025, and, in 2026, recommendations for standardized structured reporting of those examinations. Reporting guidance for perinatal and paediatric postmortem CT followed a parallel track, published in Insights into Imaging in 2024.

Standardized reporting deserves particular emphasis because it addresses one of the field’s most stubborn problems. An imaging study is only as useful as the report that follows it, and early adopters of postmortem MRI found that radiologists described findings in wildly different ways, making it difficult to compare results across centres or to accumulate the evidence base needed to convince coroners, pathologists and funders. The 2026 structured reporting recommendations aim to fix this by defining what must be documented, in what order and with what terminology, so that a postmortem MRI report from Amsterdam can be read and trusted in London, Toronto or Melbourne. It is the kind of unglamorous infrastructure work that rarely makes headlines but determines whether a technique becomes routine or remains a curiosity.

The evidence base itself has grown in parallel. One of the decade’s most influential studies, the DRIFT trial published in The Lancet Child & Adolescent Health in 2018, compared chest radiographs with computed tomography for detecting rib fractures in children and provided diagnostic accuracy data that directly inform how skeletal injury should be assessed after death. Other work has pushed into more sophisticated territory: diffusion-weighted postmortem MRI of the fetal brain has been used to help time perinatal deaths, a question with real forensic and medico-legal significance, while feasibility studies have explored multiparametric mapping and spectroscopy approaches that quantify the biochemical changes tissues undergo after death. These quantitative techniques remain largely research tools, but they hint at a future in which postmortem imaging does more than mirror autopsy — it measures things autopsy cannot.

Geography, however, remains a limiting factor. A 2023 survey of North American practice found that paediatric postmortem imaging is used far less consistently there than the European literature might suggest, and a companion European survey published the same year examined the fragile funding streams that support the work. Postmortem imaging often falls between budgetary stools: it is not routine diagnostic imaging with a living patient, nor is it always funded as part of forensic or medico-legal investigation. The commentary is candid that reimbursement and sustainable financing are now among the biggest obstacles to wider adoption, perhaps bigger than any technical question about image quality or diagnostic accuracy.

The institutional response has been to widen the coalition. In 2026, a multi-society statement on implementing paediatric and fetal postmortem imaging into clinical practice was issued jointly by the European Society of Paediatric Radiology, the Society for Pediatric Radiology, the Latin American Society of Pediatric Radiology, the Asian and Oceanic Society for Pediatric Radiology, the World Federation of Pediatric Imaging and the International Association of Forensic Radiographers. That breadth matters. It signals that the field is no longer a European project but a global one, and it gives radiologists, pathologists, coroners and health administrators on multiple continents a common reference point when they argue for local services.

Technology continues to move as well. Among the developments highlighted in the commentary’s own journal is early experience with photon-counting detector CT in paediatric postmortem imaging, a detector technology that offers higher spatial resolution and improved tissue contrast at comparable or lower radiation exposure than conventional CT. For a field whose credibility depends on detecting small, subtle findings — a hairline rib fracture, a tiny intracranial haemorrhage, a subtle malformation — such hardware advances could meaningfully shift diagnostic performance. The commentary also notes the publication of a comprehensive textbook on postmortem imaging of the fetus and child in 2025, consolidating a decade of accumulated knowledge into a single reference for practitioners entering the field.

Where does the field go from here? The commentary’s implicit answer is that the scientific groundwork has largely been laid and the remaining battles are organizational: funding, service implementation, training and the slow work of convincing legal systems and bereaved families that imaging can stand alongside — or in some cases replace — conventional autopsy. For early pregnancy loss, less-invasive autopsy approaches have already been shown to offer families answers where a full autopsy would be declined. The decade since “mortui vivos docent” has not eliminated the need for pathologists, and few in the field claim it should; instead, imaging has become a complementary tool that can guide autopsy, replace it when families refuse it, and extract information from bodies that must otherwise go unexamined. The dead, it turns out, teach the living best when the living build the systems to listen.

Subject of Research: Paediatric and perinatal postmortem imaging

Article Title: 10 years of paediatric and perinatal postmortem imaging: where are we now?

Article References: Arthurs, O. J., & van Rijn, R. R. (2026). 10 years of paediatric and perinatal postmortem imaging: where are we now?. Pediatric Radiology. https://doi.org/10.1007/s00247-026-06795-9

Image Credits: AI Generated

DOI: 10.1007/s00247-026-06795-9

Keywords: postmortem imaging, paediatric radiology, perinatal autopsy, postmortem MRI, postmortem CT, ESPR task force, less-invasive autopsy, fetal imaging, forensic radiology, structured reporting, photon-counting CT, Pediatric Radiology

The study, led by Yadigar Kastamoni and Kenan Öztürk of the Department of Anatomy at Süleyman Demirel University, together with Ahmet Dursun, Onur Can Şanlı and radiologist Veysel Atilla Ayyıldız, set out to reveal sex-related characteristics through morphometric measurements taken on the mandible, and to predict sex in individuals from different age groups using those variables. The work addresses one of the enduring challenges of forensic anthropology: identifying reliable, population-appropriate skeletal markers of sexual dimorphism that remain robust across the adult lifespan.

The research team analysed head and neck computed tomography images from 152 individuals, 77 males and 75 females, aged between 20 and 98 years. From these scans, the researchers generated three-dimensional reconstructions of each mandible using the RadiAnt DICOM viewer, a software platform that converts the two-dimensional slice data produced by CT scanners into volumetric models that can be measured in three dimensions. This approach reflects a broader shift in forensic science away from measurements taken with calipers on dry skulls and toward virtual anthropology, in which clinical imaging archives become rich sources of skeletal data.

The specific landmarks chosen for measurement were carefully selected regions of the mandible with well-established anatomical identities. The team measured dimensions relating to the foramen mentale, the mental foramen through which the mental nerve and vessels emerge on the front of the jaw; the condylus mandibulae, the rounded condyles that articulate with the skull at the temporomandibular joints; the incisura mandibulae, the notch between the condyle and the coronoid process on the upper margin of the ramus; and the angulus mandibulae, the angle of the jaw at the back and lower corner of the bone. In addition, the researchers measured the bigonial distance, the straight-line breadth of the jaw between the two gonion points at the angles on either side. All measurements, except those involving the mandibular angle, were carried out in RadiAnt DICOM Viewer 2020.1.1, and the resulting data were analysed statistically using SPSS 20.0 for Windows.

The results were strikingly consistent with the known biology of the human mandible. When the parameters were compared between the sexes, the mean values of all measurements, with the single exception of the left mandibular angle, were larger in males than in females. This pattern mirrors the influence of testosterone-driven bone growth during puberty, which produces a generally larger, squarer and more robust jaw in men, while hormonal and muscular factors in women tend to produce a jaw with a more obtuse gonial angle and finer proportions. The only measurement that failed to show a statistically significant sex difference was the gonial angle itself on the left side, a finding that reinforces a long-standing caution in the literature: angular measures of the jaw are notoriously variable and are influenced by age-related remodelling, tooth loss and chewing forces.

The degree of sexual dimorphism varied considerably across the measured parameters. The highest dimorphism rate was observed in the incisura mandibulae, the mandibular notch, which differed between the sexes by 14.39 percent on the right side and 14.29 percent on the left. At the opposite extreme, the angulus mandibulae showed almost no dimorphism, with differences of just 0.12 percent on the right and 0.57 percent on the left. This gradient is informative for forensic practice: it suggests that linear distances spanning the ramus, particularly between the mandibular condyle and the gonion, carry far more sex-diagnostic information than the angle of the jaw, which should be treated with caution when sexing fragmentary remains.

Indeed, the statistically significant differences between the sexes were found specifically in the distances from the condylus mandibulae to the gonion on both sides of the jaw, alongside the bigonial distance. These findings give forensic anthropologists a small set of hardy landmarks, robust bony points that survive decomposition and trauma relatively well, from which reliable linear measurements can be taken. Because the condyle and gonion are prominent structures on the ramus, they remain measurable even when the delicate alveolar portion of the jaw bearing the teeth has been damaged or lost, a common scenario in archaeological and forensic contexts.

What elevates the study beyond a simple descriptive anatomy exercise is its predictive modelling. The researchers built a logistic regression model from their measured variables, which correctly classified 91.4 percent of individuals in the development sample. A parallel discriminant function analysis achieved 90.1 percent classification accuracy on the original sample, and, crucially, retained 85.5 percent accuracy under leave-one-out cross-validation, a stringent test in which each individual is classified by a model trained on everyone else. The modest drop between original and cross-validated performance indicates that the model generalises reasonably well rather than simply memorising the training data, an important consideration for any method intended for real casework.

The authors conclude that sex estimation can be successfully performed using external measurements of the mandible, and they highlight the bigonial distance and the gonion-to-condyle measurements as particularly valuable parameters for sex differentiation. They suggest the method may prove useful in anatomy, forensic medicine and anthropology, especially in studies requiring sex estimation. This positions the mandible alongside the pelvis and skull as a first-rank bone for sex estimation, with particular value in contexts where those more classically dimorphic elements are missing. The mandible is also among the densest and most durable bones in the human skeleton, frequently surviving fire, fragmentation and long burial, which makes any validated method for reading sex from it disproportionately useful.

The study also carries broader implications for how forensic science will develop in the coming years. Computed tomography is now routinely performed in hospitals worldwide, and archives of clinical scans represent vast, untapped populations of reference data. Virtual osteometry of this kind does not require a physical skeleton at all: it can be applied ante-mortem to living patients in identification contexts, and post-mortem using clinical or forensic CT, avoiding destructive sampling of evidence. Earlier work cited by the team, including validation studies of three-dimensional CT measurements and postmortem CT morphometry of the mandible in Japanese populations, had already established the technical reliability of imaging-based measurement; the new study extends that framework with a large, wide-ranging adult sample spanning nearly eight decades of age, from 20 to 98 years.

As with all skeletal sex-estimation methods, population specificity remains the central caveat. The dimensions of the mandible vary across ancestral and geographic groups, and the classification functions derived here were developed on a Turkish sample; forensic practitioners applying them elsewhere would need to validate or recalibrate the model against local reference data before relying on it in identification casework. The retrospective design, approved by the Human Research Ethics Committee of Süleyman Demirel University with informed consent waived for anonymised data, also means the findings describe a clinical imaging population rather than a random demographic one. Nevertheless, with cross-validated accuracy approaching ninety percent from a handful of simple linear measurements, the message of the study is clear and, for a field where even a single additional clue can resolve an identification, quietly revolutionary: the jawbone remembers who you were, and it is willing to tell.

Subject of Research: Sex estimation from morphometric measurements of the human mandible in three-dimensional computed tomography images

Article Title: Sex estimation from the mandible in 3D computed tomography images

Article References: Kastamoni, Y., Dursun, A., Şanlı, O. C., Ayyıldız, V. A., & Öztürk, K. (2026). Sex estimation from the mandible in 3D computed tomography images. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04001-x

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04001-x

Keywords: sexual dimorphism, mandible, computed tomography, forensic anthropology, 3D imaging, morphometry, sex estimation, bigonial distance, logistic regression, discriminant analysis, human identification, osteometric analysis

Postmortem computed tomography, or PMCT, has become a mainstay of modern forensic investigation, offering a non-invasive window into projectile trajectories, fracture patterns, and the extensive osseous destruction typical of cranial gunshot injuries. Established PMCT findings include inward and outward bevelling of bone, keyhole lesions, radiating fracture lines, and the distribution of bone fragments, air, and blood along the bullet path. Yet comparatively little systematic attention has been paid to the hyperdense—radiographically bright—findings that appear at the entry wound itself. These bright foci are frequently attributed to gunshot residue, the particulate and combustion-related material expelled from a firearm upon discharge, but their morphology and underlying mechanisms have remained poorly differentiated, despite their potential forensic weight.

The new study set out to determine whether the various hyperdense patterns seen at entry sites represent a single phenomenon or a heterogeneous spectrum. Led by Radiya Sri Rajendran, with Stephan Andreas Bolliger, Michael Josef Thali, and Dominic Gascho as co-authors, the team analyzed fifty cases of gunshot wounds to the head and neck, all considered consistent with short-range shots based on forensic documentation. Thirty-five cases, seventy percent, were through-and-through injuries with an exit wound, while fifteen cases, thirty percent, involved retained projectiles. Pistols accounted for sixty-six percent of the weapons, revolvers for twenty-six percent, and rifles for eight percent, with 9 mm Para and .22 long rifle ammunition the most frequently represented calibers.

Imaging was performed on a 128-slice SOMATOM Definition Flash scanner using standardized parameters: a tube voltage of 120 kV, a tube current-time product of 400 mAs, a pitch of 0.35, and a rotation time of 1.0 second. Datasets were reconstructed at a slice thickness of 0.6 millimeters with a bone kernel to optimize visualization of radiopaque structures. Two readers with very different levels of experience independently assessed gunshot residue-related hyperdensities: Reader 1 was a physician without specific training in forensic radiology or wound ballistics, while Reader 2 was a forensic imaging specialist with thirteen years of experience. Other findings—bone fragments, fracture lines, projectile fragments, and the radiopaque ring sign—were evaluated by consensus. Agreement on residue detection was moderate, with a Cohen’s kappa of 0.55, a figure that itself underscores how difficult these distinctions can be.

The results paint a picture of considerable morphological complexity. Gunshot residue-related hyperdensities were identified in eighty-two percent of cases by the less experienced reader and seventy-two percent by the specialist, with discrepancies concentrated in cases where residue patterns were limited or diffuse. Bone fragments were the most consistent radiopaque finding at the entry site, present in the vast majority of cases, and their radiodensity frequently overlapped with that of residue, complicating differentiation. Projectile fragments, by contrast, could be reliably separated from both because of their markedly higher radiodensity—often reaching the upper measurable limit of the Hounsfield unit scale at 3071 HU—and the characteristic streak artifacts they produce. Residue itself exhibited a wide range of maximum attenuation values, from 550 to 3022 HU with a median of 1705.5, reflecting focal high-density components rather than the overall composition of the deposit.

Against this backdrop of ambiguity, the radiopaque ring sign stood out. In the three cases where it appeared, it manifested as a compact, continuous circumferential structure embedded within the subcutaneous tissue at the wound margin, clearly distinguishable from both diffuse hyperdensities and focal metallic fragments. Two of the three cases involved a revolver firing .22 long rifle ammunition, and the third involved a revolver chambered in .38 S&W. Critically, in cases with through-and-through injuries, no comparable ring-like structure was observed at the exit sites, even though those sites also contained a mixture of bone and projectile fragments. This asymmetry supports the interpretation that the ring sign is a specific phenomenon of the entry site rather than a general accumulation of radiopaque material, and all three ring-sign cases showed external findings clearly attributable to contact gunshot wounds.

The distinction matters because the forensic literature has not always separated these patterns. Early work by Stein and colleagues in 2000 illustrated gunshot residue findings on PMCT, including a ring-like accumulation reproduced experimentally in a porcine model, but did not consistently treat it as a separate entity. Later studies described residue as spontaneously dense material around entrance wounds in intermediate-range shots, implying more diffuse or surface-related patterns. Gascho and colleagues explicitly reported a subdermal ring of radiopaque material at the entry wound of neck injuries from a contact shot, and porcine cadaver experiments by Junno and colleagues in 2022 reinforced the reproducibility of a ring-shaped structure particularly in contact shots, pointing to a distance-dependent mechanism. More recently, Jupin-Delevaux and colleagues introduced the hyperdense rim sign as a marker for entry wound identification, but their definition rests largely on geometric criteria and may encompass both compact rings and ill-defined perilesional hyperdensities under a single term.

The Zurich team argues that this broader usage risks overgeneralization. Their data indicate that superficial hyperdensities at the wound margin, diffuse perilesional deposits within surrounding tissue, and the compact radiopaque ring sign likely reflect distinct underlying mechanisms. The diffuse patterns probably correspond to surface contamination and combustion-related effects, whereas the ring may arise from a more localized deposition process under specific ballistic conditions—possibly related to gases and particulates forced into the subcutaneous tissue when the muzzle is pressed against the skin. The authors also note that Hounsfield unit measurements alone cannot resolve the question, since maximum attenuation values are dominated by metallic fragments and partial volume effects, and they found that three-dimensional visualization techniques such as cinematic rendering helped in selected cases by clarifying the shape and spatial distribution of ambiguous structures.

The study’s implications extend to an open question in classical forensic pathology: whether the radiopaque ring on PMCT relates to the contusion ring seen on external examination of the skin. The authors suggest that prospective or experimental studies with standardized documentation of both external and radiological findings, ideally combined with histopathological analysis, could clarify whether the two phenomena are connected or independent. They also acknowledge limitations: the retrospective design and restriction to head and neck wounds limit generalizability to other anatomical regions; reliable discrimination among contact, near-contact, and close-range shots was not possible in every case due to tissue destruction, decomposition, or inconclusive external findings; and the subgroup of ring-sign cases is small. The imaging data themselves, containing identifiable anatomical features, are not publicly available, though they may be accessible from the corresponding author under institutional and ethical approval.

Even with those caveats, the message for forensic practice is clear. Hyperdense findings at the wound margin are common on PMCT and remain valuable for identifying entry wounds, but they should not be read as a single entity. A true radiopaque ring sign is rare, morphologically distinct, confined to the entry site, and in this cohort appeared only in contact shots, whereas other residue-related hyperdensities occur across a broader range of firing distances and demand cautious, context-informed interpretation. As virtual autopsy techniques continue to spread through forensic institutes worldwide, refining the vocabulary and diagnostic criteria for what appears on the scan could mean the difference between an ambiguous finding and decisive evidence.

Subject of Research: Radiopaque ring sign at gunshot wound entry sites on postmortem CT

Article Title: Radiopaque ring sign as a distinct finding at the entry site of gunshot wounds on postmortem CT

Article References: Rajendran, R. S., Bolliger, S. A., Thali, M. J., & Gascho, D. (2026). Radiopaque ring sign as a distinct finding at the entry site of gunshot wounds on postmortem CT. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04004-8

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04004-8

Keywords: gunshot residue, postmortem CT, radiopaque ring sign, forensic imaging, virtual autopsy, wound ballistics, entry wound, hyperdense rim sign, contact shot, forensic radiology, Radiopaque, ring