Petr Hejna

Testing photogrammetry-based techniques for three-dimensional surface documentation in forensic pathology

Three-dimensional surface technologies particularly close range photogrammetry and optical surface scanning have recently advanced into affordable, flexible and accurate techniques. Forensic postmortem investigation as performed on a daily basis, however, has not yet fully benefited from their potentials. In the present paper, we tested two approaches to 3D external body documentation - digital camera-based photogrammetry combined with commercial Agisoft PhotoScan(®) software and stereophotogrammetry-based Vectra H1(®), a portable handheld surface scanner. In order to conduct the study three human subjects were selected, a living person, a 25-year-old female, and two forensic cases admitted for postmortem examination at the Department of Forensic Medicine, Hradec Králové, Czech Republic (both 63-year-old males), one dead to traumatic, self-inflicted, injuries (suicide by hanging), the other diagnosed with the heart failure. All three cases were photographed in 360° manner with a Nikon 7000 digital camera and simultaneously documented with the handheld scanner. In addition to having recorded the pre-autopsy phase of the forensic cases, both techniques were employed in various stages of autopsy. The sets of collected digital images (approximately 100 per case) were further processed to generate point clouds and 3D meshes. Final 3D models (a pair per individual) were counted for numbers of points and polygons, then assessed visually and compared quantitatively using ICP alignment algorithm and a cloud point comparison technique based on closest point to point distances. Both techniques were proven to be easy to handle and equally laborious. While collecting the images at autopsy took around 20min, the post-processing was much more time-demanding and required up to 10h of computation time. Moreover, for the full-body scanning the post-processing of the handheld scanner required rather time-consuming manual image alignment. In all instances the applied approaches produced high-resolution photorealistic, real sized or easy to calibrate 3D surface models. Both methods equally failed when the scanned body surface was covered with body hair or reflective moist areas. Still, it can be concluded that single camera close range photogrammetry and optical surface scanning using Vectra H1 scanner represent relatively low-cost solutions which were shown to be beneficial for postmortem body documentation in forensic pathology.

Postmortem diagnosis of hypothermia

The identification of hypothermia as the cause of death has always been somewhat problematic in forensic pathology because of unspecific, inconstant, or even negative macroscopic and microscopic findings. Though the simultaneous presence of frost erythema, Wischnewski spots, hemorrhages into the synovial membrane, bloody discoloration of synovial fluid of the knee, and basal vacuolization of the renal tubular epithelial cells has been indicated as strongly supportive of fatal hypothermia, their absence does not allow the diagnosis of hypothermia to be ruled out. Postmortem biochemical investigations are valuable in detecting adaptation responses to cold stress and metabolic changes that occur following cold exposure. However, ethanol intoxication prevents appearance of adaptation responses to cold, rendering the diagnosis less obvious. Immunohistochemistry, postmortem imaging, and molecular pathology have shown promising results, although at present, they do not provide pathognomonic signs of fatal hypothermia. The aim of this article is to present a review of the literature covering the significance of different postmortem investigations that are associated with hypothermia fatalities.

Decapitation in Suicidal Hanging - Vital Reaction Patterns

Complete or incomplete decapitation as a consequence of suicidal hanging is very rare, few cases having been reported in the worldwide literature. Posthanging decapitation is typically related to a drop of several meters. Three cases of complete decapitation and one case of incomplete decapitation by suicidal hanging are reported with particular emphasis on internal findings and vital reaction patterns. Personal, circumstantial, autopsy, and toxicological data were analyzed to define basic characteristics of such extreme injuries. The crucial factor for the state of decapitation itself is the kinetic energy of the falling body, the strength of the human neck tissue, and the diameter and elasticity of the used ligature. Results of our case study suggest Simons hemorrhage and air embolism as useful autopsy findings in posthanging beheading cases. Simons hemorrhage was demonstrated in three cases of four. The test for air embolism was positive in all four cases.

Intra-thoracic injuries associated with cardiopulmonary resuscitation – Frequent and serious

AIM OF THE STUDY The aim of the study was to evaluate prevalence, seriousness and risk factors of intra-thoracic injuries (ITI) injuries associated with CPR in non-survivors after out-of-hospital cardiac arrest. METHODS This was a prospective forensic autopsy cohort study conducted in a single institution. Pathologists recorded autopsy data using standardized protocol which contained data from external and internal examination of the body focused on ITI. RESULTS In total, 80 persons were included in this study. CPR-associated injuries were found in 93.7% of cases; majority of injuries were skeletal chest fractures (rib fractures in 73.7%, sternal fractures in 66.3%). ITI were identified in 41.2% of cases. Contusion of at least one lung lobe was found in 31.2%, lung laceration in 2.5%, and hemothorax in 5.0% of cases. Transmural heart contusion was identified in 17.5% of cases; hemopericard on the grounds of right atrium rupture of aortic rupture was revealed in 8.7% of cases. Risk factor analysis did not show any statistically significant correlation between ITI and any of general data (age, gender, BMI, cause of death, season of the year or location where the body was found) or CPR specifications (type and duration of CPR, manner of chest compressions). A strong correlation between ITI and skeletal chest fractures was proven. CONCLUSION ITI present frequent and serious complications of unsuccessful CPR. ITI could contribute to the death only provided the fact that ROSC had been achieved. Correct performance of chest compressions according to guidelines is the best way to avoid ITI.

The ability to act: Multiple suicidal gunshot wounds

Multiple self-inflicted gunshot wounds are rare and usually present a challenge to the forensic pathologist in determining the manner of death. Determining a persons capability to act following a gunshot wound can be of major importance in crime scene reconstruction and in differentiation between homicide and suicide. Questions concerning the possibility of physical activity following a given gunshot wound are repeatedly raised in court. We report herein three unusual cases of suicide involving multiple gunshot wounds; all the victims suffered gunshot wounds of the head without immediate incapacitation. In the first two cases, the head was target for two gunshots. Third case was a combination of two gunshots to the head and chest. In the text, we focus on the victims ability to act after the first shot, with regards to the character and localization of the gunshot wound. Also, we focus on findings that are typical for a repeated suicidal shot.

Age and sexually dimorphic changes in costal cartilages. A preliminary microscopic study

This study reports changes in costal cartilages that appear at the microscopic level throughout life, especially during the ossification process. The work builds on the results of our previous X-ray study, which confirmed the presence of two sexually dimorphic ossification patterns. This led to questions about the existence of additional sex-specific patterns that relate to the ossification process in costal cartilages. Samples of costal cartilages and adjacent parts of the bones were obtained from the autopsies of 17 corpses. The age range among the cadavers varied greatly, from a newborn baby to 91 years of age. Sections of costal cartilage were routinely processed and stained. Alkaline phosphatase activity was detected using histochemical methods. Collagens type II and X were detected immunohistochemically by monoclonal antibodies. The results of our study show that ossification of costal cartilages can take place in the form of two individual processes, localization and time-separate. Endochondral ossifications in the region of the costochondral zone appear in the first decade, and they correspond to ossifications detected by X-ray in the second decade. The location of sex-specific ossifications is determined by the penetration of cartilage canals into the metaphysial part of the rib. Endochondral intramembranous ossifications in the reserve zone appear after the third decade. These types of ossifications correspond to central globular ossifications detected by X-ray, and they are not sexually dimorphic. They can serve for accurate estimation of age.

The diagnostic value of synovial membrane hemorrhage and bloody discoloration of synovial fluid ("inner knee sign") in autopsy cases of fatal hypothermia.

We describe and discuss autopsy findings of synovial membrane hemorrhage and bloody discoloration of synovial fluid (“inner knee sign”) within a study population comprising 36 cases of fatal hypothermia and 300 control cases. Synovial membrane hemorrhage and bloody discoloration of synovial fluid of the knees were seen in 27 cases of fatal hypothermia (75%). Though we are not dealing here with an obligatory autopsy finding in fatal hypothermia, the detection of the inner knee sign might be used as another corroborative sign of vital hypothermia after considering all differential diagnostic aspects. However, the absence of this finding does not exclude death due to hypothermia.

Complex suicide with black powder muzzle loading derringer

Planned complex suicide is defined as the combination of more than one method of suicide, previously planned by the victim, to prevent failure of the first method. Herein, we present a case of planned complex suicide, committed by a black powder muzzle loading handgun and hanging. A 39-year-old man was found dead in the bathroom of his flat, hanging by the neck with a huge atypical gunshot entrance in the right temporal region of his head with extensive backspatter. The skin defects, as well as soft tissues in the subcutaneous pocket undermining, were heavily burnt. Along the wound canal were multiple bone fragments, and at the end of the path at the left temple was an embedded lead ogival projectile with a cross shaped artificial incision at its tip. The hanging was incomplete. There were no fractures of the hyoid bone and laryngeal cartilages. Cervical muscles and vessels were intact. Simon’s sign was negative. Signs of asphyxia were not present. This is the first reported case of complex suicide with a black powder derringer and manipulated projectile.

An Unusual Zip Gun Suicide—Medicolegal and Ballistic Examination

Abstract:  Home‐made guns are imitations of typical firearms and usually have handgun characteristics. This article presents an unusual case of a suicide carried out by means of a fatal gunshot wound to the head using a home‐made zip gun. A 49‐year‐old male, with a history of paranoid psychosis was found dead in the dwelling place of a family house. The investigation at the crime scene did not lead to suspicion of a gunshot wound because of the unusual nature of the firearm used. A medical examiner diagnosed an opened head injury as the primary cause of the victim’s death. The autopsy findings provided immediate grounds for further inspection of the crime scene. Subsequently, a simple zip gun, which had been overlooked during the scene investigation, was discovered. An undeformed projectile recovered from the victim’s head was consistent with the use of the home‐made firearm. Following the completion of the investigations and autopsy, the death was classified as a suicide.

Diagnostic performance of urinary metanephrines for the postmortem diagnosis of hypothermia

The purpose of this study was to assess the diagnostic potential of urinary metanephrines and 3-methoxytyramine compared to urinary catecholamine determination in diagnosing antemortem cold exposure and fatal hypothermia. 83 cases of fatal hypothermia and 144 control cases were included in this study. Catecholamines (adrenaline, noradrenaline and dopamine), metanephrines (metanephrine, normetanephrine) and 3-methoxytyramine were measured in urine collected during autopsy. All tested analytes were significantly higher in hypothermia cases compared to control subjects and displayed a generally satisfying discriminative value, thus indicating urinary catecholamines and their metabolites as reliable markers of cold-related stress and hypothermia related-deaths. Metanephrine and adrenaline had the best discriminative value between hypothermia and control cases compared to other tested analytes, though with different sensitivity and specificity. These can therefore be considered the most suitable markers of cold-related stress.