Three-dimensional Body Surface Documentation in Forensic Pathology (original) (raw)

Photogrammetry vs CT Scan: Evaluation of Accuracy of a Low‐Cost Three‐Dimensional Acquisition Method for Forensic Facial Approximation

Journal of Forensic Sciences, 2020

Photogrammetry is a three‐dimensional acquisition method potentially applicable to the forensic field. This possibility requires the verification of its accuracy. In this study, 3D volumes of skulls are generated to compare the photogrammetry versus the CT scan. In order to provide eligible material to the photogrammetric software, photographs were captured at a distance of 30 cm from the skull placed on a support 1 m in height and illuminated with diffused laboratory ceiling artificial light. A Nikon Coolpix P7100 camera was used. Photographs capture common elements with the previous and the next photograph so as to allow the photogrammetric software to recognize these common points between photographs and create a 3D puzzle. The Zephyr Lite (3DFlow©) software was employed to register the 3D volume. CT‐based skulls are taken as a metric reference. The photogrammetry‐based skulls are then enlarged according to the measurements of some landmarks or Zygion and Zygion, the distance bet...

Using structured light three-dimensional surface scanning on living individuals: Key considerations and best practice for forensic medicine A R T I C L E I N F O

Journal of Forensic and Legal Medicine, 2018

Non-contact three-dimensional (3D) surface scanning methods have been applied to forensic medicine to record injuries and to mitigate ordinary photography shortcoming. However, there are no literature concerning practical guidance for 3D surface scanning of live victims. This paper aimed to investigate key 3D scanning issues of the live body to develop a series of scanning principles for future use on injured victims. The Pico Scan 3D surface scanner was used on live test subjects. The work focused on analysing the following concerns: (1) an appropriate 3D scanning technique to scan different body areas, (2) the ideal number of scans, (3) scanning approaches to access various areas of the body and (4) elimination of environmental background noise in the acquired data. Results showed that scanning only a required surface of the body area in the stable manner was more efficient when compared to complete 360°-scanning; therefore, it used as a standard 3D scanning technique. More than three scans were sufficient when trying to obtain an optimal wireframe mode presentation of the result. Three different approaches were suggested to provide access to the various areas of the body. Undertaking scanning using a black background eliminated the background noise. The work demonstrated that the scanner will be promising to reconstruct injuries from different body areas, although the 3D scanning of the live subjects faced some challenges.

Forensic 3D documentation of skin injuries

An accurate and precise documentation of injuries is fundamental in a forensic pathological context. Photographs and manual measurements are taken of all injuries during autopsies , but ordinary photography projects a 3D wound on a 2D space. Using technologies such as photogrammetry, it is possible to create 3D detailed, to-scale, true-color documentation of skin injuries from 2D pictures. A comparison between the measurements of 165 lesions taken during autopsies and on photogrammetrically processed pictures was performed. Different types of lesions were considered: 38 blunt force injuries, 58 sharp force injuries, and 69 gunshot injuries. In all cases, very low differences were found with mean ≤ 0.06 cm and median ≤ 0.04 cm; a mean difference of 0.13 cm was found for the blunt force injuries. Wilcoxon signed-rank test showed no statistically significant differences between the two measurement methods (p > 0.05). The results of intra-and inter-observer tests indicated perfect agreement between the observers with mean value differences of ≤ 0.02 cm. This study demonstrated the validity of using pho-togrammetry for documentation of injuries in a forensic pathological context. Importantly, photogrammetry provides a permanent 3D documentation of the injuries that can be reassessed with great accuracy at any time. Such 3D models may also be combined with 3D reconstruction obtained from post-mortem CT scans for a comprehensive documentation of the lesion (internal and external information) and ultimately used for virtual reconstruction.

Documentation and analysis of traumatic injuries in clinical forensic medicine involving structured light three-dimensional surface scanning versus photography

Journal of Forensic and Legal Medicine, 2018

Non-contact three-dimensional (3D) surface scanning has been applied in forensic medicine and has been shown to mitigate shortcoming of traditional documentation methods. The aim of this paper is to assess the efficiency of structured light 3D surface scanning in recording traumatic injuries of live cases in clinical forensic medicine. The work was conducted in Medico-Legal Centre in Benghazi, Libya. A structured light 3D surface scanner and ordinary digital camera with close-up lens were used to record the injuries and to have 3D and two-dimensional (2D) documents of the same traumas. Two different types of comparison were performed. Firstly, the 3D wound documents were compared to 2D documents based on subjective visual assessment. Additionally, 3D wound measurements were compared to conventional measurements and this was done to determine whether there was a statistical significant difference between them. For this, Friedman test was used. The study established that the 3D wound documents had extra features over the 2D documents. Moreover; the 3D scanning method was able to overcome the main deficiencies of the digital photography. No statistically significant difference was found between the 3D and conventional wound measurements. The Spearman's correlation established strong, positive correlation between the 3D and conventional measurement methods. Although, the 3D surface scanning of the injuries of the live subjects faced some difficulties, the 3D results were appreciated, the validity of 3D measurements based on the structured light 3D scanning was established. Further work will be achieved in forensic pathology to scan open injuries with depth information.

Bite mark documentation and analysis: the forensic 3D/CAD supported photogrammetry approach

Forensic Science International, 2003

Bite mark identification is based on the individuality of a dentition, which is used to match a bite mark to a suspected perpetrator. This matching is based on a tooth-by-tooth and arch-to-arch comparison utilising parameters of size, shape and alignment. The most common method used to analyse bite mark are carried out in 2D space. That means that the 3D information is preserved only two dimensionally with distortions. This paper presents a new 3D documentation, analysis and visualisation approach based on forensic 3D/CAD supported photogrammetry (FPHG) and the use of a 3D surface scanner. Our photogrammetric approach and the used visualisation method is, to the best to our knowledge, the first 3D approach for bite mark analysis in an actual case. The documentation has no distortion artifacts as can be found with standard photography. All the data are documented with a metric 3D measurement, orientation and subsequent analysis in 3D space. Beside the metrical analysis between bite mark and cast, it is possible using our method to utilise the topographical 3D feature of each individual tooth. This means that the 3D features of the biting surfaces and edges of each teeth are respected which is-as shown in our case-very important especially in the front teeth which have the first contact to the skin. Based upon the 3D detailed representation of the cast with the 3D topographic characteristics of the teeth, the interaction with the 3D documented skin can be visualised and analysed on the computer screen. #

Three-dimensional scanning -A futuristic technology in forensic anthropology

Journal of Indian Academy of Forensic Medicine, 2019

Imaging innovations assume a necessary part irrespective of the considerable evolution in the discipline of forensic anthropology. Thus, enables the anthropologist to record the site and anthropological remains in outstanding point of interest. With advancement in innovations, virtual human studies are increasing pervasively replacing conventional radiographs that have been utilized to archive specimens. The forensic anthropologists have incorporated computed tomography (CT) and three-dimensional (3D) surface scans as advanced imaging methods for their case analyses and research to obtain process and dissect 3D information. Among these methods, three dimensional scanners have picked up a conspicuous place for an assortment of reasons that make them valuable to anthropologists. These propelled imaging innovations give a way to report anthropological specimens, their injury patterns, and thus provides a platform to create virtual models for record purpose. Imaging specialists have also tried creating techniques for evaluating and utilizing various parameters from the virtual models like surface mapping and advanced methods of geomorphometric analysis. It stretches out our capacity to evaluate phenotypic variety, its non-damaging nature adds to specimen preservation, and it can turn into a basic piece of virtual human studies, along these lines accomplishing more than simply "beginning to expose what's 3D scanning is all about. The present paper provides an insight on the new scanning technology and discusses the possible future application of these techniques in forensic analysis.

VIRTOPSY—Scientific Documentation, Reconstruction and Animation in Forensic: Individual and Real 3D Data Based Geo-Metric Approach Including Optical Body/Object Surface and Radiological CT/MRI Scanning

Journal of Forensic Sciences, 2005

Until today, most of the documentation of forensic relevant medical findings is limited to traditional 2D photography, 2D conventional radiographs, sketches and verbal description. There are still some limitations of the classic documentation in forensic science especially if a 3D documentation is necessary. The goal of this paper is to demonstrate new 3D real data based geo-metric technology approaches. This paper present approaches to a 3D geo-metric documentation of injuries on the body surface and internal injuries in the living and deceased cases. Using modern imaging methods such as photogrammetry, optical surface and radiological CT/MRI scanning in combination it could be demonstrated that a real, full 3D data based individual documentation of the body surface and internal structures is possible in a non-invasive and non-destructive manner. Using the data merging/fusing and animation possibilities, it is possible to answer reconstructive questions of the dynamic development of patterned injuries (morphologic imprints) and to evaluate the possibility, that they are matchable or linkable to suspected injury-causing instruments. For the first time, to our knowledge, the method of optical and radiological 3D scanning was used to document the forensic relevant injuries of human body in combination with vehicle damages. By this complementary documentation approach, individual forensic real data based analysis and animation were possible linking body injuries to vehicle deformations or damages. These data allow conclusions to be drawn for automobile accident research, optimization of vehicle safety (pedestrian and passenger) and for further development of crash dummies. Real 3D data based documentation opens a new horizon for scientific reconstruction and animation by bringing added value and a real quality improvement in forensic science.

Intraoral Scanners in Personal Identification of Corpses: Usefulness and Reliability of 3D Technologies in Modern Forensic Dentistry

The Open Dentistry Journal

Aims: This study aims to verify the applicability of modern dental technologies and their related principles of use to the forensic sciences in the field of personal identification. Background: Personal identification has always had a major role in many legal and administrative actions regarding both living and death beings. The techniques used are much less advanced than the technologies potentially available. Objective: Modern technologies, available to the daily dental clinic practice, as intraoral scanners, combined in particular to the specialist skill in orthodontics, can help redefine the methods of personal identification according to the levels of accuracy, trueness and feasibility greater than those applied in traditional forensic dentistry. Methods: 23 corpses (12F;11M) have been selected for intraoral scanning with the Carestream 3500® digital device. The superimposition of initial and late digital models, digital models and radiographs (orthopantomography and full mouth...