Superimposed CT imaging using fusion function to visualize the relationship between the knife and the wound path in a stabbing victim

Post-mortem CT in the investigation of homicides

AIM

To investigate the reliability of post-mortem computed tomography (PMCT) in a case series of homicides involving blunt-force, sharp-force, and ballistic trauma.

MATERIALS AND METHODS

The study investigates 16 homicide cases that underwent PMCT before autopsy. Two radiologists assessed the PMCT examinations and the data were compared to the forensic pathology findings. Data were organised in broad categories: foreign bodies, external injuries, soft-tissue and organ injuries, fractures, air in cavities, fluid collections, random pathology, and wound track. Findings were organised by systems: head and neck, thorax, abdomen and pelvis, extremities. Cohen's kappa statistics were used to assess observer agreement.

RESULTS

Six gunshot-related homicides (37.5%), seven sharp-force-related homicides (43.75%), two blunt-force-related deaths (12.5%), and one homicide due to mechanical asphyxia (1.25%) were analysed. A total of 64 fractures were reported by the pathologists, 67 by radiologist 1 and 68 by radiologist 2. Agreement was deemed substantial in all cases. Pathologists failed to report gas in cavities while radiologists underreported superficial injuries.

CONCLUSION

An overall observation was that less accurate findings were produced by the blinded radiologist in comparison to the non-blinded one. The extremeness of homicides obscured the interpretation of PMCT leading to the observed discrepancies. The combination of PMCT and autopsies is deemed optimal when investigating homicidal events.

Usefulness of virtual reassembly of the skull and spine in cases of fragmentation due to high-energy trauma: A feasibility study

With the widespread use of postmortem computed tomography (PMCT) beside forensic autopsies for investigation of causes of death, three-dimensional (3D) reconstruction and fusion imaging using PMCT data are now becoming common. In the present study, the applicability of virtual reassembly from PMCT data was investigated in three cases involving fragmentation of the skull or spine due to high-energy trauma, as in such cases it is sometimes difficult to obtain detailed information on fractures using macroscopic observation alone. In the first case, virtual reassembly of the skull provided more information about the fractures than conventional reconstruction with adhesive. In the second case, although the skull was severely fractured and could not be examined macroscopically, virtual reassembly allowed detailed visualization of the fractures. In the last case, virtual reassembly of the spine helped to clarify that the 6th-8th thoracic vertebrae had been run over by a vehicle at the scene. Thus, virtual reassembly was shown to be useful for assessment of injury patterns, and event reconstruction.

Useful Evidence by Post-Mortem CT and Stereomicroscopy in Bone Injury: A Case Series from Forensic Practice

The investigation of bone injuries is an essential topic in forensics. We sometimes have to deal with charred or dismembered human remains that have lost soft tissue, making it difficult to diagnose the mechanisms of injury that led to death. Our contribution aims to share with the scientific community how we approached two cases of very different bone injuries and the techniques used to differentiate relevant pathology findings of bone fragments. Two cases are analyzed from the case history of the forensic medicine institute of Palermo. PMCT made it possible to differentiate heat bone lesions from traumatic lesions. The stereomicroscope was superior to PMCT in being able to better characterize and evaluate shear injuries, allowing a more accurate measurement of acute lesions. Injury to bone remains can be appropriately investigated with rapid techniques such as PMCT and stereomicroscopy. The presented methodology shows the importance of a multidisciplinary approach when dealing with bone injuries in forensics that could find further applications in other circumstances to answer forensic questions.

Global illumination rendering versus volume rendering for the forensic evaluation of stab wounds using computed tomography

We compared three-dimensional (3D) CT images of stabbing victims subjected to volume-rendering (VR) or global illumination-rendering (GIR), a new technique now available for the reconstruction of 3D CT images. It simulates the complete interactions of photons with the scanned object, thereby providing photorealistic images. The diagnostic value of the images was also compared with that of macroscopic photographs. We used postmortem 3D CT images of 14 stabbing victims who had undergone autopsy and CT studies. The 3D CT images were subjected to GIR or VR and the 3D effect and the smoothness of the skin surface were graded on a 5-point scale. We also compared the 3D CT images of 37 stab wounds with macroscopic photographs. The maximum diameter of the wounds was measured on VR and GIR images and compared with the diameter recorded at autopsy. The overall image-quality scores and the ability to assess the stab wounds were significantly better on GIR than VR images (median scores: VR = 3 vs GIR = 4, p < 0.01). The mean difference between the wound diameter measured on VR and GIR images and at autopsy were both 0.2 cm, respectively. For the assessment of stab wounds, 3D CT images subjected to GIR were superior to VR images. The diagnostic value of 3D CT GIR image was comparable to that of macroscopic photographs.

[Current view on stab/cut injuries]

Currently, mechanical trauma is the most significant cause of violent death. The injuries caused by sharp objects rank high in the structure of mechanical trauma. The study objective is to review domestic and foreign literature on the study of stab/cut injuries, identify the main issues and consider new promising diagnostic methods. The stab/cut wound morphology is widely described in the available literature, but little attention has been paid to their study of late postmortem changes. This issue requires consideration since putrefactive corpses (hidden by placing the corpse in water, burying it in the ground, etc.) are often the object of forensic medical examination. New methods for assessing stab/cut injuries are also considered: computed tomography, multilayer computed tomography, scanning electron microscopy, and energy dispersive x-ray spectroscopy. Each of the diagnostic methods has its undeniable advantages and prospects for widespread use in expert practice, but they cannot completely replace the main methods and are intended only to supplement them.