Radiography of perforating centerfire rifle wounds of the trunk

All deaths resulting from perforating centerfire rifle wounds of the chest and abdomen, investigated by the Office of the Chief Medical Examiner for t he Province of Alberta from 1988 to 1995, were reviewed retrospectively to determine whether the radiographic distribution of bullet fragments in such cases is a useful predictor of bullet trajectory. Study cases were limited to single gunshot wounds without surgical intervention or inter-mediate ta rgets, and for which adequate radiography was available. Three pathologists individually viewed the radiographs on two separate occasions: wound locat ions were provided for the second viewing (Group 2). Differences in opinion regarding direction of fire were resolved by consensus review. A trauma ra diologist independently made two sets of interpretations in the same way. C omparisons of these groups of interpretations were made with the actual bul let direction determined at autopsy. Of 21 cases included in the study, onl y three (14.3%) did not require consensus resolution in either group. Accur acy of pathologists' interpretation improved from 38.1% (8/21) to 76.2% (16 /21) with provision of wound locations (p = 0.012). The radiologist achieve d similar improvement, from 28.6% (6/21) to 47.6% (10/21). The rate of agre ement between radiologist and pathologists increased from 42.9% (9/21) to 6 1.9% (13/21) between Groups 1 and 2. Both the pathologists and radiologist interpreted several cases the same way in both groups; of those cases inter preted differently, the second interpretation was occasionally incorrect af ter correct interpretation in Group I. We conclude that bullet direction fo r perforating centerfire rifle wounds cannot be accurately determined from postmortem radiographs. When wound location is known, the ability to predic t bullet direction improves but is still subject to error, including a lack of consistency between observers.