Forensic Imaging最新文献

Traditional age estimation methods are prone to subjectivity, leading to a decrease in the reliability and repeatability of estimated ages in skeletal assemblages. In an attempt to reduce the level of subjectivity, this research applied a computational method designed to analyze surface topography, Dirichlet Normal Energy (DNE), to provide a mathematical assessment of age-related degeneration in the auricular surface. Reconstructed 3D models of 153 archaeological individuals were created by laser scanning and analyzed using the R studio package MolaR. DNE values showed moderate correlations with age phase (Buckberry-Chamberlain and Lovejoy), for the auricular surface as a whole as well as a number of topographical features (surface undulation, apical activity, macroporosity). Most encouragingly, this method had an extremely low levels of intra-observer error, which makes it repeatable and potentially more objective than traditional age estimation methods.

Assigned sex estimation via the greater sciatic notch (GSN) is traditionally performed via physical/visual examination and ordinal scoring; however, this relies on the subjective assessment of morphology for typological classification which may not be reflective of human variation. Three-dimensional (3D) photogrammetry may offer a technologically advanced, low cost, and more objective alternative to assess the complex curvature of anatomical landmarks. This research explores the accuracy of photogrammetry derived 3D models by comparing digital measurements to those obtained from the skeletal elements and to streamline the application of curvature analysis for the estimation of assigned sex from the GSN. This study utilizes the left and right os coxae from 15 skeletal individuals (5 females, 10 males) from the Boston University Chobanian & Avedisian School of Medicine. A Fujifilm X-Pro2 and Fujifilm 35 mm prime lens captured 123 images per element, which were processed in Meshroom by AliceVision® to create a 3D textured mesh. The mesh was exported into Blender for cleanup, scaling, measurement, and curvature analysis. The measurements were between 96.54 % and 99.94 % consistent across methods and observations. The consistency between digital metric observations increased by an average of 0.07 % when compared to the consistency of the dry bone measurements. Additionally, curvature analysis of the GSN correctly estimated the assigned sex of all os coxae in the sample. This study demonstrates that photogrammetry is an accurate and reliable method for the digitization of remains that enables analytical techniques to better capture skeletal variation compared to traditional methods.

Objectives

The purpose of this pilot study is to investigate the accuracy of mass estimation of the heart using postmortem MRI and CT in this population.

Methods

The mass of the heart was estimated using three different methods: sequential segmentation of the right and left ventricles by MRI in 30 patients; sequential segmentation of the left ventricle chamber using CT and an ellipsoid method of the left ventricle (LV) using CT in 6 patients. The estimated mass by each method was compared to conventional autopsy mass using linear regression.

Results

The correlation between estimated and measured cardiac mass using postmortem MRI measurements of the right and left ventricles, CT derived volumes of the left ventricle, or by the LV ellipsoid CT method are as follows: y = 0.87744x - 0.74813 (R² = 0.958); y = 0.6004x - 2.16 (R² = 0.8681); y = 0.6019 - 2.1615 (R² = 0.8599), respectively. When separating the fetuses evaluated by pmMRI into a ≤20 weeks subset or >20 weeks subset, the correlation are as follows: y = 0.5176x + 0.2428 (R² = 0.645) and y = 0.91237x - 1.53647 (R² = 0.9475), respectively.

Conclusion

Mass of the heart at autopsy modestly correlates with MRI derived volumes measuring the right and left ventricles. The small sample in the CT derived volume of the left ventricle alone or by the simplified estimated method using the ellipsoid measurements of the left ventricle by CT compared to autopsy weights make it difficult to conclude CT's utility using these methods.

The purpose of this study was to develop a feasible imaging protocol superior to postmortem computed tomography (PMCT) and to establish diagnostic parameters for diagnosing pulmonary thromboembolism (PE) on postmortem magnetic resonance imaging (PMMR).

The study collective of 113 subjects was prospectively investigated by PMMR for the presence of PE and / or postmortem clotting (cruor). PE was detected in 20 cases; the remaining 93 cases were investigated for the morphology of cruor. Age grading was performed by PMMR, autopsy and histology. The postmortem sedimentation effect was used for the applied imaging protocol on PMMR (supine and prone position). Visual distension of the pulmonary arteries in PE was seen in all cases, but not in the controls. Re-positioning of the corpse from supine in prone position proved to be beneficial in 90 %. Postmortem motion artifacts are firstly described in 20.4 %. Hyperacute PE (grade 1) presented with a homogenous and hypointense signal on T2w images, acute PE (grade 2) with slightly heterogeneous, but still homogenous hypointense signal, subacute PE (grade 3) was with heterogeneous and slightly hyperintense signal and chronic PE (grade 4) with predominately homogenous with scarce portions of heterogeneous but hyperintense signal. PMMR allowed for the detection of PE and for in situ depiction of combined age grading.

Objectives

In forensic identification, pelvis, post cranial bones especially long bones and skull are considered best for sex estimation. But there are circumstances where these bones cannot be recovered for establishing the correct biological profile of unknown human skeletal remains. In those cases, other skeletal bones should be investigated for sex estimation. The goal of the present study was to validate whether the patellar bone measurements through CT scan can be used for the sex estimation in Northwest Indian subjects.

Materials and methods

This study comprises of 344 subjects (179 males and 165 females) between the age group of 18- 80 years. Eight variables of patella were selected in the study for sex estimation using CT scan images of patella.

Results

All the variables were statistically significant with p-value< 0.05 for indicating the sex. Univariate and multivariate discriminant function analysis (direct and stepwise method) were applied for sex estimation. The overall accuracy rate of classifying sex was 88.4% for multivariate stepwise discriminant function analysis and 87.8% for multivariate direct discriminant function analysis. Total perimeter of patella (TPP) was found to be the best variable for sex estimation with overall accuracy rate of 84.9%.

Conclusion

The present study emphasized on the most dimorphic variables of patella in Northwest Indian subjects. New variables of patella namely Patellar Femoral Distance (PFD), Patellar Apex Angle (PAA), Frontal Surface Area of patella (FSA) and Total Perimeter of Patella (TPP) were added in the study of Indian subjects. This brought an overall accuracy rate of classification above 85%. The study confirmed that patellar bone's linear and angular measurements can be used for forensic identification casework.

Objectives

Biological Sex estimation is an essential component of the biological profile examined by forensic anthropologists, offering potential leads for identification in law enforcement and the public. Recently, attention has turned toward investigating the utility of the maxillary sinus as a tool for estimating biological sex within forensic anthropology. This research examines biological sex variation of the maxillary sinus's volume, surface area, and dimensions (length, width, and height) using a 3D model constructed from computerized tomography (CT) scans within a contemporary population in New Mexico.

Material and Methods

Automated linear, surface area, and volume measurements were performed on a reference sample (n = 90) from 45 identified males and 45 identified females using 3D modeling of CT scans through 3D Slicer©, MeshLab©, and Meshmixer© following Robles et al. (2020) [45] protocol.

Results

Statistical analysis was performed using JMP Pro16.1.0. Overall, there were no significant differences between the right and left sides of the maxillary sinus or between the biological sexes (p>0.01). The statistically insignificant results between biological sexes contradict international studies stating that the maxillary sinus is a tool that can be utilized for biological sex estimation.

Conclusion

These results could indicate that (1) sexual dimorphism within a US population is lower than in international samples and (2) sample sizes need to be increased to account for more population variation and to better interpret results. Therefore, researchers should further investigate the usefulness of the maxillary sinus as a predictive tool for estimating biological sex.

Objective

The aim of this study was to verify the application of linear, angular and area measurements using lateral teleradiography to estimate sex in a sample of the Brazilian population.

Material and Methods

Linear, angular and area measurements were performed on 320 lateral teleradiographs equally distributed between sexes. For the analyses, eight cephalometric points (glabella, orbitale, sella, basion, porion, nasion, anterior nasal spine and posterior nasal spine) were considered. Lateral teleradiography of participants aged 20–40 years was included. Examinations with trauma or cranial pathologies, changes in bone development, or artifacts that made it impossible to adequately visualize the regions of interest were excluded. Landmarks were identified using ImageJ® software version 1.52a (National Institute of Health, Bethesda, Maryland, USA).

Results

Data were organized in Microsoft© Excel© 365 software version 2204 (Microsoft Corp., Redmond, WA, USA) spreadsheets and statistically analyzed using the RStudio software version 2023.06.0+421 (R foundation, Vienna, Austria). After removing outliers, 252 exams (127 of males and 125 of females) comprised the sample. Two angular measurements (glabella-nasion-sella and porion-orbitale-glabella) and one area measurement (sella-nasion-orbitale-porion) were related to the sex variable and were used to develop a binary logistic regression (BLR) model. In the training sample, sex was estimated with accuracy of 82.14 %. In the test sample (20 % of the sample, 64 teleradiographs), the model showed accuracy of 84.38 %.

Conclusion

The BLR model developed proved to be useful for estimating sex in the evaluated sample.

Background

Age estimation of unidentified human remains is an essential for establishing the biological profile of unidentified human remains. Previous studies have investigated the value linear measurements of the frontal sinus for age estimation while the value of two-dimensional (2D) geometric morphometric measurements have not been explored for this purpose.

Objective

This study aims to evaluate the morphological variation of frontal sinus among adults Malaysian for age estimation using 2D geometric morphometric methods.

Methods

Lateral skull radiographs of 453 adult Malaysians, comprising 151 young adults (20–39 years old), 150 middle-aged adults (40–59 years old) and 152 old adults (60–79 years old), were retrieved retrospectively. Eight 2D landmarks were applied to digitalized radiographs using TPSDig2 software. 2D geometric morphometric analysis was performed by MorphoJ software.

Results

Procrustes ANOVA revealed no significant differences in shape and size (p-value > 0.05) of frontal sinus between the three age groups. However, Canonical Variate Analysis showed significant differences for Mahalanobis and Procrustes distances (p-value < 0.05) between young and old adult groups. Discriminant Function Analysis after cross-validation demonstrated an age classification accuracy of 53.5 %.

Conclusion

The study suggests that 2D geometric morphometric analysis of the frontal sinus cannot be reliably used to estimate the age of an unknown Malaysian individual.

Objectives

Postmortem computed tomography (PMCT) is widely used in forensic cause-of-death investigations, and 3D volume rendering is commonly employed for visualizing PMCT data. However, no studies have investigated the effectiveness of organ-selective 3D volume rendering for detection of organ injuries such as liver and heart. This study aimed to assess whether selective volume rendering could enhance the detectability of organ damage that is generally difficult to observe in 2DCT images.

Material and methods

Using 22 selected cases of liver or heart injury, the detectability of the injury in 2DCT images and selective volume-rendered images was compared with actual autopsy findings.

Results

Among 15 cases of liver injury confirmed at autopsy, 2DCT imaging detected two, whereas selective volume-rendered imaging detected one. Furthermore, among 17 cases of cardiac injury, 2DCT imaging detected two, whereas selective volume-rendered imaging detected four. Thus, a small proportion of liver and heart injury cases were detectable using 2DCT imaging or selective volume rendering. In all cases where selective volume rendering identified an injury, the injury was not identified by radiologist interpretation of the 2DCT images, although a review of the 2DCT images did allow identification of the injury when corroborated by the findings of selective volume rendering. One additional case demonstrated the usefulness of selective volume rendering for estimation of puncture wound direction.

Conclusions

Although selective volume rendering has seldom been effective in detecting heart or liver damage, organ-selective volume rendering may provide clues for detection of injuries that are often overlooked in 2DCT images alone.

A man in his 40s was run over by a wheel loader that was slowly backing up behind him late at night at a construction site. The driver stopped when he saw a man lying on the ground after being hit by the right rear and front wheels. Pre-autopsy postmortem computed tomography (PMCT) revealed that a portion of the left lung extended from the left axilla to the subcutaneous area of the upper arm. An oval mass with a point density of 40–60 Hounsfield units was found in the peripheral lung tissue of the left upper arm. Autopsy findings revealed extensive décollement from the left upper arm to the forearm, with a disconnected heart in the interstitial space and lung tissue straying to the central side.

There are no reports of thoracic organs straying into the upper arm subcutaneously, and when reading forensic PMCT images prior to autopsy, not only crush injury but also organs dislocation should be looked for carefully if the organ is absent.