Forensic Radiological Appearance of Explosion Injuries

Explosions can be accidental or caused deliberately by various types of explosive devices. They can result mainly in four types of injuries: thermal, blast (overpressure), projection/blunt force, and fragmentation injuries. Burns normally only occur at very close range to the explosion. Blast injuries mostly affect hollow organs such as the lungs and ears, and also require the victim to be relatively close to the epicenter to occur. They can leave telltale signs radiologically such as the “butterfly” distribution visible in blast lungs. Projection injuries are the result of an explosion violently throwing the victim against parts of the environment, or causing a person to fall down stairs, from a height, etc. The resulting injuries will be unspecific radiologically. Fragmentation wounds are caused by parts of the environment or of the exploding agent (shell fragments, shrapnel, bolts, nails, etc.) being projected at high speeds up to several hundred meters from the epicenter and resulting in ballistic injuries. Fragmentation follows similar radiological principles to gunshot wounds and can be expected to have a highly specific appearance (e.g., retained fragments within the body). Explosions form a very heterogeneous category of wounding mechanisms, literally ranging from the firecracker to the atomic bomb, and including such broad categories as accidental industrial or domestic explosions, terrorist made improvised explosive devices and the full range of military arsenal (land mines, shells, grenades, missiles, etc.). The effects of explosions can range from amusing in the case of a firecracker to the complete destruction of a city in the case of atomic bombs. Despite the wide variety of wounding potentials, some general principles can be drawn. Explosion wounding mechanisms can be classified in several manners, and here we have chosen to divide them into the four categories mentioned in the previous paragraph. We will describe each of these categories in turn, along with what can be expected to be visible radiologically. In practice, the effects of these four wound mechanisms are often seen in conjunction with each other. In this chapter, the ranges and effects mentioned focus on the types of explosions likely to be encountered by a radiologist during his career, and not on more extreme mechanisms such as atomic bomb explosions.