The Big Game: hunting for retained bullets and foreign bodies in Great War radiology.

Objectives: Searching for retained bullets has always been crucial in war surgery. Aim of this paper is to briefly outline the history of retained bullet identification methods before X-rays discovery and describe the proliferation of the most significant methods of foreign body localization during WWI.

Methods: Coeval medical journals, reference textbooks, dedicated manuals and documents have been searched and compared in multiple archives and on the internet.

Results: Before radiologic era, probing the wound was the only way to detect the bullet and minimize the need of a large surgical incision (anaesthesia was walking its first tentative steps and antisepsis still to be conceived). Nelaton's probe, specifically designed to detect General Garibaldi's retained projectile, gained popularity. Application of electricity provided further rudimental aids to find retained metals. X-rays discovery made bullet detection easy, but exact localization to guide removal was still difficult. Hundreds of imaginative X-Ray methods for localizing bullets and splinters more precisely in the countless complex wounds flourished during the Great War. Axis intersection, geometric reconstruction and anatomical criteria guided localization. Complex procedures and rudimental localizers to simplify calculations, and a number of compasses and magnetic or electric devices to aid surgical removal were developed, and are here outlined. Intermittent radiology assessment or combined radiology and surgery procedures started to play a role.

Conclusions: All these methods and tools are the ancestors of modern navigation systems, ensured by images digitalization and miniaturization technologies.

Key Words: Foreign bodies, Mobile Health Units, Radiology, X-Rays, World War I, Wounds and injuries.