501 research outputs found
Retraction: Evaluation of 3D surface scanners for skin documentation in forensic medicine: comparison of benchmark surfaces
The possibility of identifying brain hemorrhage in putrefied bodies with PMCT
This paper aims to demonstrate that post-mortem CT (PMCT) can locate intracranial hemorrhages, even in decomposed cases. This is of relevance in that post-mortem decomposition is particularly damaging to the brain tissue’s consistency, resulting in great difficulties to reliably diagnose and locate intracranial hemorrhages. We searched our case database of the last 11 years to find cases with decomposition of the body, where PMCT and an autopsy had been performed. We identified eleven cases according to these criteria. Postmortem interval ranged from 2 days to 2 weeks, and post-mortem radiological alteration index (RAI) was at or above 49. Eight out of eleven cases showed an intraparenchymal hemorrhage whereas the hemorrhage was extra-axial in the remaining three cases. Autopsy validated the presence of intracranial hemorrhage in all eleven cases, but location could not be confirmed due to liquid state of the brain. PMCT identified and localized intracranial hemorrhages in decomposed bodies, and in all of these cases, autopsy validated their presence. The actual cause of the hemorrhage (e.g. tumor, metastasis, vascular malformation, hypertensive hemorrhage) remained obscure. From this case series, it can be concluded that PMCT may add relevant information pertaining to localization of intracranial hemorrhages in decomposed bodies
Comparison of very affordable immersion pump and heart-lung-machine for post mortem CT angiography in forensic pathology – A case-control study
Full body post mortem CT angiography (PMCTA) in forensic medicine started on a larger scale with relatively expensive roller-pumps for what in essence seems to be a task consisting of pumping mostly homogenous contrast fluids. At considerably lower cost, centrifugal pumps are a technically powerful alternative. We compare a very affordable immersion pump (IP) with a heart lung machine (HLM) for an iodine based vascular contrast agent in a age-sex matched case-control study of 10 each. The IP outperformed the HLM, in part with statistical significance, depending on the aspect or metric that was compared. Concluding, the IP may be preferred as a useful and affordable alternative over a more expensive roller-pump
Digital 3D reconstruction of two parahissian accessory bundles in a case of Wolff-Parkinson-White syndrome
Three-dimensional reconstruction of digitized histological serial sections of the cardiac conduction system yielded two accessory pathways in a case of a 24-day-old male infant who died after a short period of illness with ECG findings of Wolff-Parkinson-White syndrome. In infants, the differential diagnosis of possible accessory pathways connecting the AV conduction system, atrial or ventricular septum includes dispersed conduction system tissue without connecting features. This is why three-dimensional reconstruction is necessary in order to refute or establish connectivity of cell groups as found in histological serial slice image
Anomalous Lattice Response at the Mott Transition in a Quasi-2D Organic Conductor
Discontinuous changes of the lattice parameters at the Mott metal-insulator
transition are detected by high-resolution dilatometry on deuterated crystals
of the layered organic conductor -(BEDT-TTF)Cu[N(CN)]Br.
The uniaxial expansivities uncover a striking and unexpected anisotropy,
notably a zero-effect along the in-plane c-axis along which the electronic
interactions are relatively strong. A huge thermal expansion anomaly is
observed near the end-point of the first-order transition line enabling to
explore the critical behavior with very high sensitivity. The analysis yields
critical fluctuations with an exponent 0.8 0.15
at odds with the novel criticality recently proposed for these materials
[Kagawa \textit{et al.}, Nature \textbf{436}, 534 (2005)]. Our data suggest an
intricate role of the lattice degrees of freedom in the Mott transition for the
present materials.Comment: 4 pages, 4 figure
Evaluation of 3D surface scanners for skin documentation in forensic medicine: comparison of benchmark surfaces
BACKGROUND: Two 3D surface scanners using collimated light patterns were evaluated in a new application domain: to document details of surfaces similar to the ones encountered in forensic skin pathology. Since these scanners have not been specifically designed for forensic skin pathology, we tested their performance under practical constraints in an application domain that is to be considered new. METHODS: Two solid benchmark objects containing relevant features were used to compare two 3D surface scanners: the ATOS-II (GOM, Germany) and the QTSculptor (Polygon Technology, Germany). Both scanners were used to capture and process data within a limited amount of time, whereas point-and-click editing was not allowed. We conducted (a) a qualitative appreciation of setup, handling and resulting 3D data, (b) an experimental subjective evaluation of matching 3D data versus photos of benchmark object regions by a number of 12 judges who were forced to state their preference for either of the two scanners, and (c) a quantitative characterization of both 3D data sets comparing 220 single surface areas with the real benchmark objects in order to determine the recognition rate's possible dependency on feature size and geometry. RESULTS: The QTSculptor generated significantly better 3D data in both qualitative tests (a, b) that we had conducted, possibly because of a higher lateral point resolution; statistical evaluation (c) showed that the QTSculptor-generated data allowed the discrimination of features as little as 0.3 mm, whereas ATOS-II-generated data allowed for discrimination of features sized not smaller than 1.2 mm. CONCLUSION: It is particularly important to conduct specific benchmark tests if devices are brought into new application domains they were not specifically designed for; using a realistic test featuring forensic skin pathology features, QT Sculptor-generated data quantitatively exceeded manufacturer's specifications, whereas ATOS-II-generated data was within the limits of the manufacturer's specifications. When designing practically constrained specific tests, benchmark objects should be designed to contain features relevant for the application domain. As costs for 3D scanner hardware, software and data analysis can be hundred times as high compared to high-resolution digital photography equipment, independent user driven evaluation of such systems is paramount. INDEX TERMS: Forensic pathology, Rough surfaces, Surface Scanning, Technology Assessmen
Visual note - large vitreous hemorrhage in post mortem imaging
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
Virtopsy concept around the world: Institute-based survey of worldwide forensic postmortem imaging
Introduction:
Forensic routine postmortem imaging in excess of photography and conventional X-ray has been pushed since a few years, in some instances under the name ”Virtopsy”. It constitutes a pivotal innovation in forensic medicine as it allows for the non-invasive exploration of the deceased through diverse imaging techniques. This study offers an analysis of a survey with focus on the worldwide adoption and application of postmortem imaging. Our goal is to uncover and understand regional variances in its deployment application. Methods: A survey comprising 18 questions, both closed-ended and open-ended, was designed collaboratively and distributed globally via email and social network. The survey addressed topics such as autopsy rates, imaging modalities, indications for postmortem imaging, personnel involved, evaluation methods, and communication of findings. The survey was initially sent to institutes with published postmortem imaging research, and later, it was distributed through international forensic radiology and radiographer associations. Statistical analysis was conducted to interpret the results. Results: Responses were obtained from 29 countries, representing 6 continents, with a total of 100 participating institutions. European institutions were predominant (69%), followed by Australia (9), North America (8), Asia (7), Africa (6) and South America (1). The majority of institutions reported 100-500 autopsies annually (31). Among the institutes that reported that they perform post mortem imaging (PMI), most listed postmortem computed tomography (PMCT) as modality (89%). The request to perform PMI was issued by institutes of forensic medicine (51%), researchers (42%), police (43%) or public prosecutor’s office (54%). 48% of the respondents stated that an autopsy must always be performed, even if the cause and manner of death can be ascertained by postmortem imaging. radiographers were primarily responsible for technically performing PMCT (65%) whereas physicians were listed in 28%, autopsy technicians in 18%. The majority of the institutions (32%) identified clinical radiologists as the primary individuals responsible for reading, evaluating radiological images, and writing reports. Many respondents (64%) reported that their image readers had attended specialized postmortem imaging courses. Communication of findings typically involved written reports (28%) or a combination of written reports and illustrated images (31%). Membership of survey respondents was indicated in 38% for the International Society of Forensic Radiology and Imaging (ISFRI) and 5% for the International Association of Forensic Radiographers (IAFR). The question was how many of the responders are members of a PMI focused radiological society or work group. 52% (44 out of 85) respondents indicated they were not a member of a postmortem imaging society. The memberships listed are ISFRI (38%), IAFR (5%) and AGFB (Arbeitsgruppe Forensische Bildgebung, 4%). Conclusion: This study provides a global perspective on the utilization of postmortem imaging in forensic medicine, revealing regional variations in practices and technology adoption. It offers insights into the personnel, techniques, and procedures involved in this field in different countries
Mobile forensic photogrammetry in the field: Conservative approach to non-collaborative surfaces
Conventional photogrammetry faces challenges with non-textured, transparent, or reflective surfaces, affecting accurate 3D modeling, particularly in forensic documentation. This study evaluates improvements using lower exposure, exposure bracketing, and RAW format for better 3D modeling of non-textured surfaces. Two bodies were photographed under controlled conditions to assess techniques for non-textured surfaces, with a comparison set for textured surfaces. The experiments were conducted in an autopsy room with a Nikon D5500 camera, adjusting for low exposure, exposure bracketing, RAW format, and increased photo redundancy. Models with Meshroom (Alicevision). Our focus was on visual plausibility rather than quantitative metrics. Results indicated that using RAW format with exposure bracketing and low exposure significantly improved 3D models by reducing artificial edges seen with standard JPG images, despite some noise. A redundant series of RAW photos further reduced edge artifacts and noise, demonstrating the effectiveness of averaging photos to enhance model quality. However, these modifications showed marginal improvements on textured surfaces, underscoring their significant benefits primarily for non-textured surfaces. This study highlights the potential of modified photogrammetry techniques in forensic science, particularly for documenting challenging surfaces. It points out the need for further research, given its limitations in sample size and the absence of extensive parameter testing and quantitative analysis
Prevalence of calcified epiglottis in postmortem computed tomography. Is there a correlation to failed endotracheal intubation?
Objectives: Calcification of the epiglottis is a normal physiological degenerative process, although it can also be a consequence of infection or trauma. There are three possible forensically relevant consequences from epiglottic calcification: misinterpretation as foreign bodies, dysphagia as a major contributing factor to aspiration, and association with difficult intubation or a misplaced ventilation tube. It is the aim of this study (I) to inquire about the prevalence of epiglottic calcification in postmortem CT in general and (II) to investigate whether calcification of the epiglottis is linked to a higher incidence of failed endotracheal intubation.
Methods: We retrospectively analysed 2930 consecutive cases in postmortem CT at the Institute of Forensic Medicine. Results: The prevalence of epiglottic calcification was 4.1%. Higher age and male sex are associated with an increased risk of epiglottic calcification. There was no calcification of the epiglottis in the cases with misplacement of the ventilation tube in the esophagus.
Conclusions: To verify the result of our study, that is, the calcification of the epiglottis is not linked to a higher incidence of failed endotracheal intubation, it might be reasonable to repeat this study with a more representative study population. The high interindividual variations of calcified epiglottis could be used for identification
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