Echographic detection and localization of BB shots in the eye and orbit.

BB shots and other spherical foreign bodies produce long chains of rapidly successive echo spikes which gradually decrease in height. These patterns are specific for this type of foreign bodies and allow their reliable detection and accurate localization. A-scan echography has become a very useful addition to X-ray examination in order to determine whether such foreign bodies are intra- or extraocular. Echography also helps to localize such foreign bodies during surgery and to evaluate the posterior segment of the eye in the presence of opaque ocular media (hemorrhages, cataract). Although it is sometimes possible to demonstrate specific B-scan patterns of spherical foreign bodies, A-scan echography is the method of choice since it is faster, more reliable and more accurate.