E1380. Don’t Go Ballistic on Me: A Primer on Gunshot Wounds with Bullet Points for the Musculoskeletal Radiologist
  1. Gregory Stacy; University of Chicago
In the United States, there is a gunshot injury approximately every 5 minutes, resulting in over 30,000 deaths per year; this makes gunshot injuries the second leading cause of death following motor vehicle collisions. The purpose of this exhibit is to familiarize musculoskeletal radiologists with the appearance of various types of bullets and the injuries they cause.

Educational Goals / Teaching Points
After viewing this exhibit, the participant will (1) understand basics of ballistics, the study of projectiles in motion, (2) recognize different bullet types and their appearances on radiographs, and (3) understand wound patterns as they pertain to bone and soft tissue injury.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Wound ballistics, a subset of terminal ballistics, refers to the study of the effects of a projectile on living tissues. Most bullets used by civilians have a lead core, not uncommonly completely or partially surrounded by a metal jacket, and may have soft- or hollow-points to promote expansion. The design of the bullet influences its wound pattern, including the permanent wound tract through soft tissue and temporary cavitation. Handgun bullets typically yield characteristic “low energy” fracture patterns, with greater degrees of comminution associated with higher projectile velocity and larger expanding bullets. Newer bullets, including varieties made entirely of copper, consist of “trocars” designed to fragment in soft tissue creating multiple individual wound channels; such bullets can be identified with accuracy on radiographs, with potential implications for future magnetic resonance imaging.

Gunshot injuries are common in many cities, and radiologists should have a basic understanding of ballistics, bullet design, and wound patterns in order to provide meaningful reports to aid patient care.