Comparative Evaluation of Potentially Radiolucent Projectile Components by Radiographs and Computed Tomography (original) (raw)
Related papers
Is CT bulletproof? On the use of CT for characterization of bullets in forensic radiology
International Journal of Legal Medicine
Purpose Forensic investigations could benefit from non-invasive in situ characterization of bullets. Therefore, the use of CT imaging was explored for the analysis of bullet geometry and composition. Bullet visualization with CT is challenging as the metal constituents suffer from excessive X-ray attenuation due to their high atomic number, density, and geometry. Methods A metal reference phantom was developed containing small discs of various common metals (aluminum, iron, stainless steel, copper, brass, tungsten, and lead). CT images were acquired with 70-150 kVp and 200-400 mAs and were reconstructed using an extended Hounsfield unit (HU) scale (− 10,240 to + 30,710). For each material, the mean CT number (HU) was measured to construct a metal database. Different bullets (n = 11) were scanned in a soft tissue-mimicking phantom. Bullet size and shape were measured, and composition was evaluated by comparison with the metal database. Also, the effect of bullet orientation within the CT scanner was evaluated. Results In the reference phantom, metals were classified into three groups according to their atomic number (Z): low (Z ≤ 13; HU < 3000), medium (Z = 25-30; HU = 13,000-20,000), and high (Z ≥ 74; HU > 30,000). External bullet contours could be accurately delineated. Internal interfaces between jacket and core could not be identified. Cross-sectional spatial profile plots of the CT number along bullets' short axis revealed beam hardening and photon starvation effects that depended on bullet size, shape, and orientation within the CT scanner. Therefore, the CT numbers of bullets were unreliable and could not be used for material characterization by comparison with the reference phantom. Conclusion CT-based characterization of bullets was feasible in terms of size and shape but not composition.
Forensic Science International, 2003
Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot's wound ballistic effects was not possible. The aim of our study was to evaluate whether the progress in imaging techniques over the last years has made it possible to establish an observer-independent and reproducible forensic assessment using multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) technologies for the documentation and analysis of gunshot wounds. The bodies of eight gunshot victims were scanned by MSCT and by MRI; the data of these imaging techniques were post-processed on a workstation, interpreted and subsequently correlated with the findings of classical autopsy.
International Journal of Legal Medicine, 2019
The aim of this study is to assess the added value of post-mortem computed tomography (PMCT) in fatal shooting incidents compared with autopsy findings. For this study, the analysis was restricted to the following four features: location of the entrance and exit wounds, internal injuries, location of projectiles or metal fragments and course of the trajectories. These features were selected because they provide essential information on the cause and manner of death. All data were retrospectively collected from medical forensic examinations of fatal shooting incidents in the Netherlands that occurred in 2010-2014. Twenty-one fatal shooting victims were included in this study, with a total of 100 trajectories. For all 100 trajectories, the forensic radiologist and pathologist came to a consensus on which examination had the highest diagnostic value for each of the four features. PMCT provides superior information on the presence of metal fragments, internal injuries and the course of trajectories. PMCT provides limited information on the discrimination of entrance and exit wounds. In conclusion, PMCT provides additional relevant information in over 60% of forensic medical examinations of deceased victims of shooting incidents. We therefore recommend adding PMCT as a standard examination in these cases.
Post-autopsy computed tomography. Pros and cons in a firearm death
Forensic Science International, 2017
Many studies have focused on the importance of post-mortem computed tomography (PMCT) prior to or in substitution of standard forensic autopsies in case of firearm death. However, due to the fact that PMCT is not routinely performed in all countries, in cases of death abroad it can happen that a CT scan is performed only after a first autopsy. A case of post-mortem re-examination, including the external examination and a post-autopsy computed tomography (PACT), of a gunshot victim of homicide in a foreign country is presented, and the pros and cons of imaging in post-autopsy setting are discussed. PACT could be a tool for carrying out more complete investigations and for obtaining information on bone injuries and foreign bodies trapped within peripheral soft tissues that can be re-analyzed after the arrival of the first autopsy report. Given that the value of information derived may be strongly influenced by the previously performed autopsy, in order to process the definitive considerations it is necessary to compare and interpret the data obtained through PACT with the 2 results of the first autopsy, and to continue the international cooperation effort and the application of international guidelines in order to share information at the repatriation of the corpse.
Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series
Journal of Forensic Sciences, 2020
Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner's office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re-evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head-neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar's test. We included 60 males and 20 females (median age 31 years, range 3-73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head-neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs.
Conventional radiographs: are they still the standard in localization of projectiles?
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007
The penetration of air gun pellets in facial soft tissue can cause major problems during the removal of foreign bodies, although conventional radiography, computed tomography, image-guided surgical removal, and ultrasound have been applied to facilitate the procedure. It was the aim of the present case report to introduce a modified intraoperative method for the localization of air gun pellets, based on the use of radiopaque markers in conventional radiographs. A 66-year-old patient attempted to commit suicide by using an air gun. The pellet hit the right temporal region. A computed tomographic (CT) scan was acquired to localize the foreign body. The first attempt to remove the pellet through the penetrating wound failed. Because of a dislodgement of the pellet, the CT scan could no longer be used for the localization of the air gun pellet. As the air gun pellet was positioned under the zygomatic arch, ultrasound was unable to identify its position. Successful intraoperative localization of the projectile was performed after fixation of radiopaque markers to the skin in the region of the estimated localization, with conventional radiographs in 2 planes, acquired with a mobile dental x-ray device. Although the markers remained attached to the patient as reference makers, the air gun pellet was removed easily. The use of radiopaque markers in conventional radiographs in 2 planes allows fast, intraoperative localization of radiopaque foreign bodies within soft tissue. The procedure can be carried out with a conventional x-ray device that should be available in every oral and maxillofacial practice. The use of reference markers should be considered a standard procedure for the localization of radiopaque foreign bodies in the head and neck. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:e71-e75)
An Unconventional CT Post-Processing Software to Analyze a Difficult Intracranial Bullet’s Ballistic
Research Journal of Diagnostic Radiography, 2013
In this paper, we used a software commonly applied in the field of radiation therapy, to identify the spatial position of the target volume of the tumors, to define with accuracy the spatial position of a bullet, and its intra-cranial route. We report a case of intra-cranial bullet's finding, in which after reconstructions, it was possible to define a pathway suggest for a shot fired from the bottom upwards, with an incidence's angle suggesting for a suicide instead an homicide The use of this software, may be a valuable source for scientific data, not only for a purely clinical care, but also for forensic evaluations, as evidence to be provided in court. The applicability of this methodic, is in principle desirable, into an emergency contest, to define the intra-cranial ballistic of bullet, to identify more precisely the injured tissues, and in forensic analysis, after specialistic and more complex analysis, to determine the position of eventual aggressors.
Gunshot to the pelvis – Experimental ballistics and forensic radiology
Journal of Forensic Radiology and Imaging, 2014
The 9 mm Luger full metal jacket and 44 Rem. Mag. semi-jacketed hollow point were fired at a body model consisting of a polyurethane pelvis with gelatine prior to multislice computed tomography (MSCT) and the results compared to those obtained by dissection of the model.
American Journal of Roentgenology, 1990
Radiologists can contribute substantially to the evaluation and treatment of the patient with a gunshot wound. Plain films, CT, angiography, and sometimes MR imaging are used to localize the missile, determine what path it followed in the body, assess missile and bone fragmentation, and identify missile emboli. If the peritoneal cavity was entered by a bullet, a laparotomy is required. Missiles subject to magnetic forces can complicate MR imaging. Certain locations of missile fragments predispose to lead poisoning or lead arthropathy. Angiography is useful for both diagnosis and treatment. Both angiographic hemostasis and percutaneous foreign body removal may be used. Gunshot wounding is an interaction between the penetrating projectile, the anatomy of the wounded subject, and the chance occurrences that determine the exact missile path. The mass and velocity of the projectile establish the upper limit of possible tissue damage. Whether this potential is realized, and where, depends on what tissue the missile encounters, whether the missile fragments or expands, and at what point along the missile path yaw occurs. (Yaw is the angle between the long axis of the bullet and its path of flight.) The radiologist can contribute substantially to the successful treatment of the patient with a gunshot wound. Important