Computed tomography of scalp embedded gravel: Differentiation between falling and kicking

• Medicolegal mechanism differentiation.
• Experimental approach to solve a case.
• Quantitative post mortem CT evaluation.
• Differentiation of fall versus kick against head.

In the case of a survived head injury of a 39 year old man, kick versus fall as mechanism had to be discerned. On top of conventionally used medicolegal findings, clinical computed tomography (CT) scans were evaluated. There, dense particles at the back of the head were scattered on and in the skin, around the region also likely to be the center of an impact related skull burst fracture. Experiments then were conducted to discern falling, kicking and scrubbing, based on gravel particle details, using suitable model substrate materials. Particle size and count were larger in falls without scrubbing than in kicks also because soles may not retain heavier or larger gravel particles. Based on chemical composition obtained through EDS (energy-dispersive X-ray spectroscopy), gravel particle mass attenuation coefficient was determined, linearly correlating with effective CT attenuation of scalp particles and bone and skin materials. Gravel particle size showed to be a stronger evidence in the distinction of fall versus kick than skin and brain morphology. Clinical CT can be a valuable asset in reconstructive forensic medicine.