Postmortem 3-D reconstruction of skull gunshot injuries

doi:10.1016/j.forsciint.2013.08.012

Forensic Science International

Volume 233, Issues 1–3, 10 December 2013, Pages 45-50

https://doi.org/10.1016/j.forsciint.2013.08.012 Get rights and content

Abstract

Background

In cases of severe decomposition or skeletonization of a corpse after cerebral gun shot injury it is difficult to exactly reconstruct the bullet path in the brain. However, in case of murder or homicide this might become necessary to answer forensic questions such as the ability to move or other actions of the victim.

Materials and methods

Therefore a method in terms of three dimensional reconstruction technique was developed by fusing computed tomography scans (CT) of the original skull and magnetic resonance images (MRI) of a normal brain of adequate size. Hereby five cases were investigated.

Results

In three cases an excellent concordance between the reconstructed bullet trajectory and the autopsy reports was achieved. In one case the original brain was not available for CT-scanning due to previous autopsy. However, the findings were in line with the pathology report. In one case there was a difference of about 1–2 cm between the original autopsy description and the reconstructed bullet path. This was due to only a part of the skull being available for image reconstruction.

Conclusion

The findings suggest that this method can successfully be applied to adequately reconstruct bullet paths in cases of completely skeletonized skulls, but should carefully be used in cases of incomplete skulls.

Introduction

For the evaluation of gunshot wounds of the skull in the daily practice of forensic autopsy the focus is set on the differentiation between bullet entrance and exit as well as on the distance between muzzle and bullet entrance. The documentation of the bullet path is important to be able to draw conclusions regarding the ability of action associated with particularly injured cerebral structures. Until now, this may be a difficult or even impossible task in cases of severe decomposition or skeletonization. On the occasion of an overseas homicide case, a second autopsy was performed in our university forensic department. Since in this case there was no brain available for evaluation the present study was performed. The aim was to primarily investigate the usefulness of radiological methods regarding the reconstruction of bullet trajectories in cases of no further evaluable brain after e.g. gun shot injuries.

Section snippets

Materials and methods

In total five cases of gun shot injury to the skull were investigated. In four cases a complete autopsy protocol was available including the skull and brain. In those cases when the skull was macerated, it subsequently underwent CT scanning using a spiral CT protocol (PQ 6000, Philips Medical Systems, Best, Netherlands, formally known as Picker International, Cleveland, OH, USA) with the following raw data acquisition parameters 120 kV, 100 mAs and pitch of 1.25 as well as the following image

Results

Autopsy findings (for more details see Table 1)

(A)
70 years old male, suicide

Unknown caliber; the skull was seized by the state attorney, but in the case files of the department details concerning caliber and weapon were not documented. The file documentation of the police department was not available any more.

bullet entrance: right temporal region
bullet path: bullet ascending into the right frontal lobe with affection of the anterior part of the right ventricle
bullet exit: left lateral frontal

Discussion

The increasing use of cross sectional imaging in the field of forensic medicine had encouraged several centers of forensic medicine to evaluate the use of computed tomography (CT) and magnetic resonance imaging (MRI) in the mortuary. Although neither CT nor MRI can provide histological information on the type of tumor or other subtle pathological changes or even isolate specific micro-organisms, cross sectional imaging gives the pathologist a unique perspective on the anatomy and

References (21)

K. Yen et al.
Post mortem forensic neuroimaging: correlation of MSCT and MRI findings with autopsy results
J. Forensic Sci. Int.
(2007)
E. Aghayev et al.
Pneumomediastinum and soft tissue emphysema of the neck in postmortem CT and MRI: a new vital sign in hanging?
J. Forensic Sci. Int.
(2005)
M.J. Thali et al.
Image-guided virtual autopsy findings of gunshot victims performed with multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) and subsequent correlation between radiology and autopsy findings
J. Forensic Sci. Int.
(2003)
E. Aghayev et al.
Virtopsy hemorrhage of the posterior crocoarytenoid muscle by blunt force to the neck in post mortem multislice computed tomography and magentic resonance imaging
Am. J. Forensic Med. Pathol.
(2006)
K. Yen et al.
Strangulation signs: initial correlation of MRI, MSCT and forensic neck findings
J. Magn. Reson. Imaging
(2005)
J.R. Jeffrey et al.
Computed tomography of projectile injuries
Clin. Radiol.
(2008)
K. Yen et al.
Virtopsy: forensic traumatology of the subcutanteous fatty tissue; multislice computed tomography and magnetic resonance imaging as diagnostic tool
J. Forensic Sci.
(2004)
E. Aghayev et al.
Virtopsy post mortem mulislice computed tomography and magnetic resonance imaging demonstrating descending tonsillar herniation: comparison to clinical studies
Neuroradiology
(2004)
C. Jackowski et al.
Adipocere in postmorten imaging using multislice computed tomography and magnetic resonance imaging
Am. J. Forensic Med. Pathol.
(2005)
B. Jacob et al.
Multiple suicidal gunshots to the head
Am. J. Forensic Med. Pathol.
(1989)

There are more references available in the full text version of this article.

Cited by (26)

Post-mortem CT in the investigation of homicides
2023, Clinical Radiology
To investigate the reliability of post-mortem computed tomography (PMCT) in a case series of homicides involving blunt-force, sharp-force, and ballistic trauma.
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.
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.
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.
Metal artifact reduction for intracranial projectiles on post mortem computed tomography
2020, Diagnostic and Interventional Imaging
To compare the image quality of cranial post-mortem computed tomography (CT) obtained with and without projection-based single-energy metal artifact reduction (SEMAR) in cadavers with intracranial metallic ballistic projectiles.
From January 2017 to January 2018, cadavers with ballistic projectile head wounds with metal fragments and without massive head destruction were investigated using post-mortem CT. All subjects underwent CT using a conventional iterative reconstruction (IR) and SEMAR. To evaluate the impact of metallic artifacts, the total intracranial area (TA), non-interpretable zone (NIZ), disturbed interpretation zone (DZ), and artifact total surface (ATS) were delineated. Two independent readers identified extra-axial hemorrhage (EAH) and subarachnoid hemorrhage (SAH). Autopsy reports were used as the standard of reference.
Eleven corpses (10 males, 1 female; mean age, 62.8 ± 17.9 [SD] years) were evaluated. SEMAR showed a significant decrease in the ATS ratio with respect to conventional IR (72.1 ± 26.1 [SD] % [range: 26.8-99.1] vs. 86.4 ± 17.8 [SD] % [range: 37.2-100]; P < 0.001) and NIZ/TA ratios (11.6 ± 8.26% [range: 0.95–33.4] versus 42.5 ± 30.5% [range: 3.86–100]; P < 0.001). The interobserver reproducibility in diagnosing EAH and SAH was excellent with conventional IR (0.82) and good with SEMAR (0.75). SEMAR reduced uncertain diagnoses of EAH in 7 subjects for Reader 1 and in 6 for Reader 2, but did not influence the diagnosis of SAH for either reader.
SEMAR reduces the influence of metallic artifacts and increases the confidence with which the diagnosis of EAH can be made on post-mortem CT.
Combined use of postmortem 3D computed tomography reconstructions and 3D-design software for postmortem ballistic analysis
2017, Diagnostic and Interventional Imaging
Citation Excerpt :
The reconstruction of the victim's position with animation software can then explain the particularities of the projectile trajectory (Fig. 3). The abundant literature on the value of post-mortem CT, particularly concerning ballistics, supports its routine use in criminal proceedings [5–8]. We have demonstrated that these data should be used both before and after autopsy in order to obtain a high-quality report and, that they also establish a definitive record of all aspects of the injury before any dissection.
Traumatic brain injury: Comparison between autopsy and ante-mortem CT
2017, Journal of Forensic and Legal Medicine
Citation Excerpt :
Furthermore, digital data can be easily stored, and cases can be re-examined decades later, even after burial of the body and liberation of the crime scene.5 Post-mortem CT has been determined to be superior to autopsy in the detection of gas accumulation and metallic foreign bodies, and it provides valuable information for the establishment of trauma patterns and accident reconstruction.2,6–9 However, clinical radiology and post-mortem imaging are not the same, and radiologists are at risk of misinterpreting findings if they rigorously apply the rules of clinical radiological analysis to post-mortem analysis.9,10
The aim of this study was to compare pathological findings after traumatic brain injury between autopsy and ante-mortem computed tomography (CT). A second aim was to identify changes in these findings between the primary posttraumatic CT and the last follow-up CT before death.
Through the collaboration between clinical radiology and forensic medicine, 45 patients with traumatic brain injury were investigated. These patients had undergone ante-mortem CT as well as autopsy. During autopsy, the brain was cut in fronto-parallel slices directly after removal without additional fixation or subsequent histology. Typical findings of traumatic brain injury were compared between autopsy and radiology. Additionally, these findings were compared between the primary CT and the last follow-up CT before death.
The comparison between autopsy and radiology revealed a high specificity (≥80%) in most of the findings. Sensitivity and positive predictive value were high (≥80%) in almost half of the findings. Sixteen patients had undergone craniotomy with subsequent follow-up CT. Thirteen conservatively treated patients had undergone a follow-up CT. Comparison between the primary CT and the last ante-mortem CT revealed marked changes in the presence and absence of findings, especially in patients with severe traumatic brain injury requiring decompression craniotomy.
The main pathological findings of traumatic brain injury were comparable between clinical ante-mortem CT examinations and autopsy. Comparison between the primary CT after trauma and the last ante-mortem CT revealed marked changes in the findings, especially in patients with severe traumatic brain injury. Hence, clinically routine ante-mortem CT should be included in the process of autopsy interpretation.
The diagnostic value of forensic imaging in fatal gunshot incidents: A review of literature
2017, Journal of Forensic Radiology and Imaging
Citation Excerpt :
This stresses the need for forensic experience when reading these studies [30]. Other studies also often failed to report how experienced the radiologists and pathologists were [7,12,15–20]. There is furthermore no consensus on the optimal reading and reporting strategy of forensic radiology studies and the especially on the use of the use of multiplanar and 3D reconstruction methods.
Post-mortem computed tomography (PMCT) and post-mortem magnetic resonance imaging (PMMR) are frequently used as an addition to autopsy. However, there is no research that determined the diagnostic value of these imaging techniques in forensic cases. The aim of this review is to evaluate the available literature with regard to the correlation between autopsy and imaging findings in the forensic investigation of gunshot victims to arrive at an the diagnostic value of PMCT and PMMR.
The review process was set out as a systematic review according to the Cochrane guidelines. A systematic search was performed in MEDLINE and EMBASE to identify studies comparing autopsy and imaging techniques after fatal gunshot incidents. Autopsy and imaging techniques were compared for forensically relevant items: entrance wounds, exit wounds, trajectory of the bullet through the body, detection of metal fragments and identification of relevant injuries. The autopsy was the reference standard in all studies.
In each study a minimum of one and a maximum of five items could be compared between the imaging techniques and the autopsy. In total seven studies complied with the inclusion criteria. The overall quality and level of detail of these studies did not allow for a formal meta-analysis. For the detection of the entrance wound five studies provide data and the correlation between imaging and autopsy was 100% in four studies, and 69.2% in one study. Five studies provide data on the exit wound and there was a 100% correlation in four, and 52.2% in one study. Six studies provide data on the bullet path and the correlation between techniques and autopsy was 100% in four studies and respectively 72.1% and 80% in the other two studies. For the detection of metal fragments three studies provide data and all these studies showed a 100% correlation between imaging and autopsy. Two studies provide data on detecting injuries with a correlation between imaging and autopsy of 100% and 87.2% respectively.
Despite the concerns on the quality of the reviewed studies, the literature shows that PMMCT has a high sensitivity in identifying the main forensic items in gunshot victims compared to the standard of reference; an autopsy. Forensic radiology and autopsy can be complementary in a forensic medical investigation.
A systemic review on ricochet gunshot injuries
2017, Legal Medicine
Ricocheted bullets may still retain sufficient kinetic energy to cause gunshot injuries. Accordingly, this paper reviews the literature surrounding gunshot injuries caused by ricocheted bullets. In doing so, it discusses the characteristics of ricochet entrance wounds and wound tracks, noting several important considerations for assessment of a possible ricochet incident. The shapes of ricochet entrance wounds vary, ranging from round holes to elliptical, large and irregular shapes. Pseudo-stippling or pseudo-gunpowder tattooing, pseudo-soot blackening and tumbling abrasions seen on the skin surrounding the bullet hole are particularly associated with ricochet incidents. Ricocheted bullets have a reduced capability for tissue penetration. Most of the resulting wound tracks are short, of large diameter and irregular—all artefacts of the instability of a bullet that has ricocheted. A ricocheted hollow-point bullet, in particular, may overpenetrate the tissue when the bullet nose is deformed or fails to enter the body in a nose-forward orientation. Similarly, internal ricochet may occur when a bullet strikes hard tissue. Postmortem computed tomographic imaging is useful for localising a bullet and its fragments in the body and characterising the wound track. Ricochet cannot be ruled out in normal-appearing entrance wounds unless that finding is supported by other evidence, including the geometrical constraints of the shooting scene and the absence of ricochet marks and a ricocheted bullet.

View all citing articles on Scopus

View full text

Postmortem 3-D reconstruction of skull gunshot injuries

Abstract

Background

Materials and methods

Results

Conclusion

Introduction

Section snippets

Materials and methods

Results

Discussion

J. Forensic Sci. Int.

J. Forensic Sci. Int.

J. Forensic Sci. Int.

Virtopsy hemorrhage of the posterior crocoarytenoid muscle by blunt force to the neck in post mortem multislice computed tomography and magentic resonance imaging

Am. J. Forensic Med. Pathol.

Strangulation signs: initial correlation of MRI, MSCT and forensic neck findings

J. Magn. Reson. Imaging

Computed tomography of projectile injuries

Clin. Radiol.

Virtopsy: forensic traumatology of the subcutanteous fatty tissue; multislice computed tomography and magnetic resonance imaging as diagnostic tool

J. Forensic Sci.

Virtopsy post mortem mulislice computed tomography and magnetic resonance imaging demonstrating descending tonsillar herniation: comparison to clinical studies

Neuroradiology

Adipocere in postmorten imaging using multislice computed tomography and magnetic resonance imaging

Am. J. Forensic Med. Pathol.

Multiple suicidal gunshots to the head

Am. J. Forensic Med. Pathol.