title: Decreased subject contrast and summation artifact: an explanation for a nearly imperceptible bullet by X-ray examination.
abstract: X-ray examination is used to detect foreign bodies during forensic autopsy of a suspected gunshot wound case. There are several previously described situations in which a projectile is not immediately localized by radiography. In this report, we present a case of a metal bullet lodged near the atlanto-occipital junction, where it was present but not readily apparent on radiograph. Although computed tomography is ideal for detecting such objects, many forensic pathologists must still rely on x-ray only. To our knowledge, the forensics literature does not contain a case where a lead bullet was rendered nearly imperceptible by x-ray examination. We describe 2 concepts of radiation physics-poor x-ray penetration and summation artifact-which can cause a radiopaque object such as a bullet to seem much less so. The difference between best practices in hospital and forensic radiology may explain how this occurred. This case serves to caution the pathologist that forensic radiographs may not completely depict the type or quantity of projectiles present in a gunshot wound case.
authors.affiliation: From the *Indiana University School of Medicine-South Bend, South Bend; †Radiology, Inc, Mishawaka; and ‡South Bend Medical Foundation, Indiana University School of Medicine-South Bend, South Bend, IN.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Graham
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Tawadros
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Prahlow
mesh_terms: D000328:Adult; D017809:Fatal Outcome; D044709:Forensic Ballistics; D049429:Forensic Pathology; D020197:Head Injuries, Penetrating / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D011859:Radiography; D014948:Wounds, Gunshot / Q000000981:diagnostic imaging* / Q000473:pathology