Clinical forensic imaging and fundamental rights in Austria

Clinical forensic imaging encompasses the diverse application of imaging procedures that serve the same purpose:to enable the analysis and investigation of criminal activities and consequences of a crime.All kinds of imaging techniques and their corresponding images can be subsumed under“forensigraphy”,a more comprehensive term for forensic imaging created by the Ludwig Boltzmann Institute for Clinical Forensic Imaging in Graz,Austria.As the word forensigraphy suggests,criminal imaging material should be of use in forensic investigations.Ideally,this can lead to new findings that would not have been revealed without the application of imaging techniques and are moreover admissible as evidence in criminal proceedings.However,the admissibility of evidence can only be facilitated through the implementation of clinical forensic imaging techniques into the forensic routine case work,which requires a precise pre-analysis of the corresponding legal framework.Because taking and displaying internal images of a person’s body touches upon various aspects of one’s physical and psychological integrity,imaging methods in general and clinical forensic imaging methods especially have a strong impact on and interfere regularly with the fundamental rights of the concerned person.Particularly with regard to a possible medical context,certain legal regulations have to be taken into account.Therefore,this paper examines forensic imaging in the field of radiological forensigraphy,specifically its in vivo(i.e.clinical)application.It is designed to enlighten readers as to the great significance of legal barriers that emerge from fundamental rights,as laid down in the European Convention on Human Rights(ECHR),when dealing with clinical forensic imaging.As a result,the legal framework of clinical forensic imaging procedures are comprehensively described,the relevant fundamental rights,especially the right to respect for private and family life,the right to data protection and certain procedural guarantees,are concisely presented to further raise awareness regarding the importance of fundamental rights.

Overview of clinical forensic services in various countries of the European Union

Examination of a person who has been a victim of a physical or sexual assault may be very important for upcoming legal proceedings.In the context of a clinical forensic examination,physical findings are recorded and biological trace material is gathered and secured.Ideally,all forensic findings are documented in a detailed report combined with photographic docu-mentation,which employs a forensic scale to depict the size of the injuries.However,the integrity of such forensic findings depends particularly on two factors.First,the examination needs to be conducted professionally to ensure that the findings are properly admissible as court evidence.Second,the examination should take place as soon as possible because the opportunity to successfully secure biological samples declines rapidly with time.Access to low-threshold clinical forensic examinations is not evenly provided in all member states of the European Union(EU);in some states,they are not available at all.As part of the JUST_(e)U!(Juridical standards for clinical forensic examinations of victims of violence in Europe)pro-ject,the Ludwig Boltzmann Institute for Clinical Forensic Imaging in Graz,Austria created(in cooperation with its international partner consortium)a questionnaire:the purpose was to collect information about support for victims of physical and/or sexual assault in obtaining a low-threshold clinical forensic examination in various countries of the EU.Our paper pro-vides a summary of the responses and an overview of the current situation concerning pro-vided clinical forensic services.

CT-scan vs.3D surface scanning of a skull:first considerations regarding reproducibility issues

Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.

A fatal case of oxygen embolism in a hospital

This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter connected to a nasal cannula delivering oxygen(O_(2))from the wall.Extensive medico-legal examinations were performed,including post-mortem computed tomography(CT),complete conventional autopsy,histological and immunohistochemistry analysis,toxicological analysis and post-mortem chemistry.Additionally,CT-guided gas sampling was performed at multiple sites to collect samples for gas analysis.During the external examination,massive subcutaneous emphysema was visible over the entire surface of the body.The CT scan revealed the presence of gas throughout the vascular system,and in the subcutaneous and muscular tissues.The autopsy confirmed the presence of lobar pneumonia and multiple gas bubbles in the vascular system.The gas analysis results showed a subnormal concentration of oxygen,confirming the suspected pure O_(2) embolism.Moreover,the carbon dioxide(CO_(2))concentration in the gas sample from the heart was elevated to a level similar to those found in scuba diving fatalities.This could come from degassing of dissolved CO_(2) that accumulated and was trapped in the cardiac cavity.Based on the results of the different exams performed,and especially the gas analysis results,it was concluded that the cause of death was O_(2) embolism.

Virtual anthropology:a preliminary test of macroscopic observation versus 3D surface scans and computed tomography(CT)scans

Virtual anthropology(VA)is based on applying anthropological methods currently used to analyse bones to 3D models of human remains.While great advances have been made in this endeavour in the past decade,several interrogations concerning how reliable these models are and what their proper use should be remain unanswered.In this research,a fundamental assumption of VA has been investigated:if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media.In order to answer,10 skulls of known age and sex were scanned using a computed tomography(CT)scanner and a 3D surface scanner.Two observers separately applied a defined staging method to eight suture sites on these skulls,first looking at the bone macroscopically,then at the 3D surface scan,and finally on the CT scan.Two rounds of observation were carried out by each observer.Intra-and inter-observer error were evaluated,and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations.The results show a high degree of inter-observer error,and that data obtained from 3D surface scans differ from macroscopic observation(confidence level 95%,P≤0.05).CT scans,in these settings,yielded results comparable to those obtained through macroscopic observations.These results offer many possibilities for future research,including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment.All current methods used in traditional anthropology should be tested,and if they prove unreliable,new techniques to analyse bones from virtual models should be developed.

Sex estimation in a Turkish population using Purkait’s triangle:a virtual approach by 3-dimensional computed tomography(3D-CT)

Sex estimation is considered one of the first steps in the forensic identification process.Morphological and morphometrical differences between males and females have been used as means for morphoscopic and metric methods on both cranial and postcranial skeletal elements.When dry skeletal elements are not available,virtual data can be used as a substitute.The present research explores 3-dimensional(3D)scans from a Turkish population to test a sex estimation method developed by Purkait(2005).Overall,296 individuals were used in this study(158 males and 138 females).Purkait’s triangle parameters were measured on computed tomography(CT)scans obtained from both right and left femora of each patient at the Bakirkoy Dr.Sadi Konuk Training Research Hospital(Istanbul,Turkey).Intra-and inter-observer errors were assessed for all variables through technical error of measurements analysis.Bilateral asymmetry and sex differences were evaluated using parametric and non-parametric statistical approaches.Univariate and multivariate discriminant function analyses were then conducted.Observer errors demonstrated an overall agreement within and between experts,as indicated by technical error of measurement(TEM)results.No bilateral asymmetries were reported,and all parameters demonstrated a statistically significant difference between males and females.Fourteen discriminant models were generated by applying single and combined parameters,producing a total correct sex classification ranging from 78.4%to 92.6%.In addition,over 67%of the total sample was accurately classified,with 95%or greater posterior probabilities.Our study demonstrates the feasibility of 3D sex estimation using Purkait’s triangle on a Turkish population,with accuracy rates comparable to those reported in other populations.This is the first attempt to apply this method on virtual data and although further validation and standardisation are recommended for its application on dry bone,this research constitutes a significant contribution to the development of population-specific standards when only virtual data are available.

Integration of Trace Images in Three‑dimensional Crime Scene Reconstruction

Forensic image analysis has greatly developed with the proliferation of photography and video recording devices.Trace images of serious incidents are increasingly captured by first responders,witnesses,bystanders,or surveillance systems.Image perception is exposed with a special emphasis on the influence of the field of view on observation.In response to the pitfalls of the mental eye,a way to systematize the integration of images as traces in three‑dimensional crime scene reconstruction is proposed.The systematic approach is based on the application of photogrammetric principles to slightly modify the usual photographic documentation as well as on the early collection and review of available trace images.The integration of images as traces provides valuable contributions to contextualize what happened at a crime scene based on the information that can be obtained from images.In a wider perspective,the systematic analysis of images fosters the use and interpretation of forensic evidence to complement witness statements in the criminal justice system.This article outlines the benefits of integrating trace images into a coherent reconstruction framework in order to improve interpretation of their content.A solution is proposed to integrate perception differences between the field of view of cameras and the human eye.