Virtopsy hemorrhage of the posterior cricoarytenoid muscle by blunt force to the neck in postmortem multislice computed tomography and magnetic resonance imaging

In forensic autopsies, one of the most important and common signs of violence to the neck is hemorrhages of the soft tissues. The Institute of Forensic Medicine in Bern evaluates the usefulness of postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) of forensic cases prior to autopsy. The aim of this study was to prove the sensitivity of postmortem MSCT and MRI in the detection of hemorrhages of the neck muscles. A full body scan prior to and a detailed scan of the explanted larynx after autopsy were performed. MSCT detected multiple fractures of the larynx. Detailed MRI was able to demonstrate the hemorrhage of the left posterior cricoarytenoid muscle. The minor hemorrhage of the right posterior cricoarytenoid muscle could not be detected with certainty. Although more experience is required, we conclude that combined MRI and MSCT examination is a useful tool for documentation and examination of neck muscle hemorrhages in forensic cases.     

Why We Need Postmortem Analysis of Cardiac Implantable Electronic Devices

The prevalence of cardiac implantable electronic devices (CIEDs), pacemakers and implantable cardioverter defibrillators (ICDs) is increasing. However, postmortem analysis of CIEDs is not performed routinely. Fourteen consecutive CIEDs were analyzed. The indication for and date of implantation, technical data, CIED reprogramming, heart rhythm disturbances, patient demographics and medical consultations were investigated. Death during the first year after implantation was seen in 54%, whereof 71% consulted a physician within 10 days before death. The time of death was attributed to a particular day in 29%. There was a relationship between CIEDs and cause/manner of death in 50%. Although limited by a small sample size, this study advocates the routine postmortem CIED analysis for forensic and clinical purposes in selected cases. Patients with CIEDs seem to show an increased risk of death during the first year after implantation. The analysis of CIEDs can be helpful in evaluating the time/cause/manner of death.     

Body models in forensic ballistics: reconstruction of a gunshot injury to the chest by bullet fragmentation after shooting through a finger.

Forensic science uses substitutes to reconstruct injury patterns in order to answer questions regarding the dynamic formation of unusual injuries.Using a case study, an experimental simulation of a finger was designed, for the first time with a combination of hard wood and glycerin soap. With this model as an intermediate target simulation, it was possible not only to demonstrate the "bullet-body (finger) interaction", but also to recreate the wound pattern found in the victim.This case demonstrates that by using ballistic models and body-part substitutes, gunshot cases can be reproduced simply and economically, without coming into conflict with ethical guidelines.     

Analysis of patterned injuries and injury-causing instruments with forensic 3D/CAD supported photogrammetry (FPHG): an instruction manual for the documentation process

Forensic 3D/CAD supported photogrammetry (FPHG) is a method of recording and documenting the surface of small objects, thus enabling a three-dimensional image of these objects in virtual space. With this representation on the computer screen the course of forensically relevant events can be reconstructed. The procedure allows for examining patterned injuries of skin, soft tissue or bones for matching potentially incriminated instruments in shape, size and angle.3D recording of objects to be examined requires taking series of photographs. A computer system then calculates the position in space of certain points on the surface of the objects and subsequently produces 3D data models of the objects. Using a 3D/CAD program these data models are used to generate graphic true-to-object volume models.The objects in question can then be moved against each other arbitrarily on the screen-depending on the questions to be answered-in order to compare them and possibly establish their congruence.This article covers the state of the art in FPHG procedures in the form of a step-by-step instruction. It also illustrates the wide range of FPHG applications.     

Is Differentiation of Frequently Encountered Foreign Bodies in Corpses Possible by Hounsfield Density Measurement?

Abstract:  The radiological determination of foreign objects in corpses can be difficult if they are fragmented or deformed. With multislice computed tomography, radiodensities—referred to as Hounsfield units (HU)—can be measured. We examined the possibility of differentiating 21 frequently occurring foreign bodies, such as metals, rocks, and different manmade materials by virtue of their HU values. Gold, steel, and brass showed mean HU values of 30671–30710 (upper measurable limit), mean HU values for steel, silver, copper, and limestone were 20346, 16949, 14033, and 2765, respectively. The group consisting of objects, such as aluminum, tarmac, car front-window glass, and other rocks, displayed mean HU values of 2329–2131 HU. The mean HU value of bottle glass and car side-window glass was 2088, whereas windowpane glass was 493. HU value determination may therefore help in preautopsy differentiation between case-relevant and irrelevant foreign bodies and thus be useful for autopsy planning and extraction of the objects in question.     

Haptics in forensics: The possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun.The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan.The haptic device is used in combination with the software FreeForm Modelling Plus™ for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury.The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.