Forensic volumetric visualization of gunshot residue in its anatomic context in forensic post mortem computed tomography: Development of transfer function preset. (June 2021)

• Record Type: Journal Article
• Authors: Schweitzer, Wolf; Verster, Janette; Aldomar, Eloisa; Ebert, Lars; Bolliger, Stephan A.; Thali, Michael J.; Ampanozi, Garyfalia
• Is Part Of: Forensic Imaging. Volume 25(2021)
• Publication Date: 2021-06
• Subjects: Virtopsy -- post mortem computed tomography -- forensic visualization -- gunshot -- gunshot residue
• DOI: 10.1016/j.fri.2021.200451
• Languages: English
• ISSNs: 2666-2256

Abstract

Highlights: Technical development of a fast implementation for use of preset function. Relevant visualization for Gunshot Residue in Forensic Routine PMCT. Statistical basis for preset function based on probabilistic model. Abstract: While the visualization of gunshot injuries so far focused on solid metal density in routine forensic post mortem computed tomography (PMCT) as well as in micro-computed tomography, gunshot residue (GSR) as dispersed metal particles typically succumbs to partial volume effect. A case series of seven contact shots to the head was evaluated to determine a density range for GSR with at least three times higher likelihood than encountering bone, skin, muscle or blood. For that, a Bayesian likelihood was determined from normal distributions of the CT-densities of blood, bone, skin, muscle and GSR as identified in correlation with visual evidence. Resulting transfer functions matched ring and cone shaped GSR deposits as published elsewhere, thus representing a plausible result. Only fast and plausibly specific visualization is suitable for routine use in forensic PMCT, to allow the examination of GSR in real cases on a wider scale.