Julien Ognard1,2, Brieg Dissaux1, Idris Diallo3, Lakdar Attar4, Claire Saccardy5, Douraied Ben Salem1,2. 1. From the Forensic Imaging Unit, University Hospital of Brest. 2. Laboratoire de traitement de l'information médicale-LaTIM (Inserm UMR 1101), Brest. 3. Imaging and Radiology Service, Cornouaille Hospital of Quimper, Quimper. 4. French National Forensic Science Institute, Lyon. 5. Clinical Forensic Medicine and Pathology, University Hospital of Brest, Brest, France.
Abstract
OBJECTIVE: The aim was to determine if dual-energy computed tomography (DECT) can discriminate ferromagnetic bullets from nonferromagnetic ones. METHODS: The ferromagnetic properties of 29 bullets were determined. All bullets underwent a DECT evaluation, and a manual measurement of the dual-energy index was performed by 2 radiologists, followed by a fully automatic measurement, in 3 different positions in a phantom (air, water, and bone). RESULTS: Twenty-one bullets were found to be nonferromagnetic. There were significant differences between the mean of the dual-energy index measured in the core of ferromagnetic projectiles and those of nonferromagnetic ones in the lung position of the phantom (P = 0.007). Specificity was 86.36%, and negative predictive value was 90.48%. Among the 29 bullets, 24 were correctly classified. CONCLUSIONS: Our study demonstrates that DECT can assess the ferromagnetic status of bullets and their magnetic resonance imaging compatibility using an extended computed tomography scale in an ex vivo phantom model.
OBJECTIVE: The aim was to determine if dual-energy computed tomography (DECT) can discriminate ferromagnetic bullets from nonferromagnetic ones. METHODS: The ferromagnetic properties of 29 bullets were determined. All bullets underwent a DECT evaluation, and a manual measurement of the dual-energy index was performed by 2 radiologists, followed by a fully automatic measurement, in 3 different positions in a phantom (air, water, and bone). RESULTS: Twenty-one bullets were found to be nonferromagnetic. There were significant differences between the mean of the dual-energy index measured in the core of ferromagnetic projectiles and those of nonferromagnetic ones in the lung position of the phantom (P = 0.007). Specificity was 86.36%, and negative predictive value was 90.48%. Among the 29 bullets, 24 were correctly classified. CONCLUSIONS: Our study demonstrates that DECT can assess the ferromagnetic status of bullets and their magnetic resonance imaging compatibility using an extended computed tomography scale in an ex vivo phantom model.