CT and MRI of a transcardiac gunshot wound with an annular distribution of bullet fragments surrounding an exit-re-entrance wound after the bullet burst from a floor tile upon exiting the lying body

This case report describes medicolegal examinations of a decedent with a fatal gunshot wound. The decedent lied on the floor as a bullet was fired into his chest. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed as part of the judicial investigation. The MRI examination was valuable for delineating the wound channel through the left ventricle, which was deemed the main cause for internal bleeding and fatal blood loss. The diagnostic value of CT for the detection of injuries was low in this case. However, CT allowed for the virtual investigation of bullet fragments. According to CT-based dual-energy index calculations, it could be inferred that the fragments were most likely made of lead matching .357 Magnum R–P cartridges that were found at the scene. The bullet fragments were located underneath the skin at the suspected exit wound. The exit wound was actually an exit-re-entrance wound, as it can be assumed that the fragments re-entered the body after the bullet burst from hard ground upon exiting the body of the decedent, who was lying on the floor. CT visualized an uncommon annular distribution pattern for the bullet fragments surrounding the exit-re-entrance wound. The formation of such an annular distribution pattern of bullet fragments and the relevant conclusions that may be drawn from such a distribution pattern are discussed in this article