Movement of steel-jacketed projectiles in biological tissue in the magnetic field of a 3-T magnetic resonance unit

Gunshot wounds to the head: a comparison of postmortem magnetic resonance imaging, computed tomography, and autopsy

BACKGROUND

Postmortem imaging has become a powerful diagnostic tool in forensics. Postmortem computed tomography (PMCT) is often used currently to complement and sometimes even replace an autopsy.

PURPOSE

To compare PMCT, postmortem magnetic resonance imaging (PMMRI), and autopsy findings for gunshot wounds to the head.

MATERIAL AND METHODS

Cross-sectional study. We performed a retrospective analysis of 24 cases with gunshot wounds to the head that underwent both PMCT and PMMRI between 2011 and 2018 at the Institute of Forensic Medicine, University of Zurich (Switzerland).

RESULTS

Our study confirms that PMCT and, to a slightly lesser degree, PMMRI provide additional information that is valuable when combined with autopsy findings. Air embolism was solely detected in PMCT (67% vs. 0% at autopsy). A retained bullet or projectile and bone fragments were diagnosed more frequently with PMCT (42%, 67%, and 92%) than at autopsy (33%, 42%, and 46%). Soft tissue lesions were more often detected with PMMRI than with PMCT. With regard to autopsy, subdural hemorrhage and ventricular hemorrhage were slightly more frequently diagnosed with PMMRI (63% and 75% vs. 38% and 58% at autopsy). Intracerebral hemorrhage was by far most often diagnosed with PMMRI (92%) compared with both PMCT (38%) and autopsy (14%).

CONCLUSION

All three modalities should ideally be considered in cases of craniocerebral gunshot wounds. However, it might be conceivable that depending on the forensic query, PMCT and PMMRI may be an adequate replacement for an autopsy.

Imaging Ballistic Injuries

Here in Canada, we often think of gun violence as confined to conflict zones, terrorism, and more of a problem for our southern neighbor. However, in recent years, it has also become a Canadian problem with increased gun violence related to criminal activity presenting in daily practice. Radiologists play a critical role in the evaluation of ballistic trauma and must therefore be familiar with both the common and uncommon patterns of ballistic injury. In this article, we review the mechanisms of ballistic trauma as well as their resultant injury patterns in order to guide image interpretation.

Neurosurgical Care of Nonpowder Firearm Injuries: A Narrative Review of the Literature

Background

Nonpowder firearms discharge a projectile using compressed gases. Unlike traditional firearms, there is a perception that nonpowder guns do not cause serious injury. However, intracranial injury disproportionally affects children and can cause significant neurological disabilities and mortality. Management of nonpowder firearm injuries has received little attention in the literature and presents unique surgical challenges.

Materials and Methods

We conducted a narrative review of the literature of the management of nonpowder firearm injuries with particular emphasis on intracranial injury.

Results

Modern nonpowder firearms have muzzle velocities which are capable of penetrating the skin, eyes, and bone. Direct intracranial injury commonly results from entrance of projectile through thinner portions of the skull. Operative intervention is needed to debride and safely explore the trajectory to remove fragments which can easily cause neurovascular injury.

Conclusions

Neurosurgeons play a crucial role in managing serious nonpowder firearm injuries. A multidisciplinary team is needed to manage the direct results of penetrating injury and long-term sequalae.