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.

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.

The significance of vitreous hemorrhages detected after death, particularly in non-traumatic cases, currently seems largely unclear. This obscurity might arise partly because these hemorrhages may go undetected, especially when relying solely on traditional methods like external inspection and autopsy. In this case of an 80-year-old woman with a history of arterial hypertension, post mortem computed tomography (PMCT) showed intrabulbar findings indicative of a lateral vitreous haemorrhage of the left eye, which then appeared partly dark on susceptibility weighted post mortem magnetic resonance imaging (PMMRI). PMMRI also identified a dislocated membrane suggestive of retina detachment. Dissection of the enucleated eye revealed a dark red gel-like mass, visually identified as clotted blood, and a retinal tear. The finding is discussed as possible consequence of arterial hypertension. Further investigations into the significance of post-mortem vitreous hemorrhages on imaging are warranted, especially in the context of potential early indicators of acute stroke.

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.

A man in his 80s was found lying at the roadside and later confirmed dead at a hospital. Subsequent investigation suggested that the deceased might have been struck by a car. Inspection of the suspect vehicle revealed a bent at the left front bumper, and the lower part of the left front light was found to be covered with the deceased's hair and sebum. Postmortem computed tomography (PMCT) and autopsy findings suggested that the deceased may have been struck by the vehicle from the right side first, given the severe damage to the right side of the body, including abrasions, the right chest bruising, and multiple fractures of the right ribs. To clarify the mechanism of injury, a 3D model of the bones arranged in three postures, including standing, prone and crouching patterns created from PMCT data, was fitted to a car of the same model as the suspect vehicle using augmented reality (AR). This revealed that the lower part of the left frontal light, where the victim's hair and sebum had been found, matched the location of the skull fracture if the victim had been in a crouching posture. Moreover, in this posture, the location of the right rib fracture coincided with the left front part of the car. Therefore, the deceased was most likely initially struck by the car from the right side when in a crouching position. AR visualization using PMCT-based antemortem posture reconstruction may facilitate detailed simulation of the injury mechanism and reconstruction of the scene.

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 diagnostic assessment of sudden and unexpected cardiovascular deaths remains intricate in forensic medicine. Building upon the foundational technique introduced by P. Fais et al.(2018), we present modifications to the post-mortem infrared coronary angiography (PIC) tailored specifically for the assessment of human hearts. Refinements to PIC encompass the integration of a 3D-printed clamp for catheter stabilization and the procedural alteration of utilizing warm water injections, negating the need for additional cardiac cooling. An enhanced imaging modality is achieved using the FLIR Thermal Lepton 3.5 camera, embedded within the robust Cat S62 Pro mobile device, ensuring optimal resolution and suitability for an autopsy environment. The advanced PIC technique provides superior visualization of the coronary arteries, frequently correlating with subsequent autopsy and histological assessments. Notably, the method allows immediate continuation to the autopsy without compromising the cardiac structure. Nevertheless, certain anatomical variances, such as muscular bridging or pronounced pericardial fat, might reduce locally what appears to be an otherwise excellent specificity. The refined PIC method emerges as a pivotal diagnostic adjunct in forensic evaluations of sudden cardiovascular fatalities. Its ability to preserve cardiac integrity and facilitate uninterrupted autopsy progression underscores its potential utility. However, rigorous validation is imperative to ascertain its comprehensive applicability and inherent limitations.

The present study aimed to test the applicability of Walker`s method in the Croatian population by using multi-slice computed tomography (MSCT) scans of a head from the University hospitals (UHC) in Split and Zagreb. Cranial morphological traits (nuchal crest, mastoid process, supraorbital edge, and glabella) were scored from images of 280 adult patients with balanced distribution according to sex and geographical region. Differences between Split and Zagreb samples were visible through principal component analysis (PCA) with Split individuals being more robust, that also reflected in specific differences in trait expression like mastoid process (P = 0.001) and supraorbital edge (P = 0.003) in male samples. Original equations did not perform well in our population, with accuracy ranging from 62 % to 70 % with low accuracy in females (48 % - 56 %). We developed 15 population-specific equations that comprised all possible combinations with single or multiple variables. The best performing equation was the one that included glabella and mastoid process that showed the least interregional variabilities and achieved accuracy of 86.25 %. To enable a direct application of equations developed we provided on-line app called CroWalker, available at: https://crowalker-rvhw.onrender.com/.

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.

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.