Morphological findings in the brain after experimental gunshots using radiology, pathology and histology

Abstract

The tissue disruption inside the brain after experimental gunshots to the head was investigated with special reference to secondary bone missiles and intracranial pressure effects such as cortical contusion and deep intracerebral haemorrhages. The evidential value of various examination methods is compared. 9 mm Parabellum ammunition was fired to the temporal region of calves (n = 10) from a distance of 0-10 cm. Plain film radiography, CT, MRI, visual inspection and histology were performed on every brain. The tissue disruption of the permanent tract is delineated best by artefact-free MRI. Cortical contusions and deep intracerebral haemorrhages were detected infrequently by visual inspection and imaging techniques although they were present in every brain as verified by histology. These injuries remote from the tract increase cerebral wounding compared to non-confined tissue. In particular, the brain stem and central areas were frequent sites of haemorrhages, which can be expected to have serious and immediate consequences. Ectopic bone fragments were found in all brains using CT scans. Bone fragments were located inside clearly enlarged permanent tracts or were driven into brain tissue. In the latter cases, secondary shot channels up to 4 cm in length could be verified by histology. Cortical contusions and intracerebral haemorrhages can only be detected reliably by histology. The localization of bone fragments requires CT scans. Therefore, a detailed examination is accomplished best by a combination of the methods applied in this study.