Using the iPhone's LiDAR technology to capture 3D forensic data at crime and crash scenes

Background: Three-dimensional (3D) documentation of crime and crash scenes is common practice during forensic and medicolegal investigations. Such documentation at a scene is usually carried out by specially trained personnel using various 3D imaging devices and methods, such as terrestrial laser scanners. Unfortunately, this causes the implementation of 3D documentation at the scenes to be expensive and not readily accessible. In 2020, Apple introduced a light detection and ranging (LiDAR) sensor into their high-end mobile devices. In 2022, Recon-3D, an iOS application (app), was launched. This app turns an iPhone or iPad into a 3D scanner and is specifically targeted at crime and crash scene applications. Objectives: The aim of this study was to test the Recon-3D app based on exemplary scenarios to see whether this technology is generally applicable to document crime or crash scenes. Materials and Methods: An iPhone 13 Pro in combination with the Recon-3D app was used to document two indoor scenarios, a mock-up crime scene and a garage, as well as an outdoor scenario of a parked car. Each scenario was documented multiple times. Results: On average, data acquisition for one scene took less than 2 min. Known distances within the scenes were measured with a mean absolute error of 0.22 cm and a standard deviation of 0.18 cm. Conclusion: The imaging workflow was simple and quick, enabling any person to perform 3D documentation at a crime or crash scene. Overall, Recon-3D appeared to be a useful application for forensic investigators

Cinematic rendering of a burst sagittal suture caused by an occipito-frontal gunshot wound

The computed tomography (CT) scan of a 19-year-old man who died from an occipito-frontal gunshot wound presented an impressive radiating fracture line where the entire sagittal suture burst due to the high intracranial pressure that arose from a near-contact shot from a 9 mm bullet fired from a Glock 17 pistol. Photorealistic depictions of the radiating fracture lines along the cranial bones were created using three-dimensional reconstruction methods, such as the novel cinematic rendering technique that simulates the propagation and interaction of light when it passes through volumetric data. Since the brain had collapsed, depiction of soft tissue was insufficient on CT images. An additional magnetic resonance imaging (MRI) examination was performed, which enabled the diagnostic assessment of cerebral injuries

Assessment of a newly designed double-barreled bullet-shooting stunner for adequate stunning of water buffaloes

To ensure animal welfare at slaughter, rapid stunning is required to render the animal deeply unconscious. In cattle, captive-bolt stunners are typically used for this purpose. However, with regard to their impact force and maximum length of approximately 120 mm, such captive-bolt stunners are not suitable for stunning water buffaloes due to anatomical characteristics of the skull. In water buffaloes the bone layer is thicker and the distance from the point of attachment of the captive-bolt stunner to the relevant brain region is longer. For this reason, a special bullet-shooting stunner was developed, which is similar in size and handling to a standard captive-bolt stunner, but instead of a bolt, it fires a bullet. Actually, even two bullets can be loaded so that a follow-up shot can be fired immediately if necessary. In this study, the bullet-shooting stunner was tested using two different types of hunting ammunition for stunning water buffaloes during regular slaughter

BigBovid- Evaluation of a Newly Developed 9 mm Bullet-Shooting Stunner for Adequate Stunning of Heavy Cattle

The stunning of heavy cattle and water buffalo is an animal welfare problem, as conventional cartridge fired captive-bolt stunners are not suitable due to the thicker skull bones and the greater depth of penetration required to reach and damage the relevant brain regions for deep unconsciousness. This current animal welfare problem requires a suitable and feasible as well as commercially available and legally approved stunning device to ensure deep unconsciousness of these animals. In this study, the use of a newly developed bullet-shooting stunner, the BigBovid, with two different types of hunting ammunition, namely .38 SPL FMJ-TC and .357 MAG FTX ® bullets, was evaluated on 22 heavy cattle (mean weight: 1062.27 kg, standard deviation: 124.09 kg). In ballistic experiments, the BigBovid reached a mean energy density of 8.18 J/mm2 (mean error: 0.45 J/mm2) for the .38 SPL FMJ-TC and 17.56 J/mm2 (mean error: 2.67 J/mm2) for the .357 MAG FTX ®. In in vivo experiments, the use of the .38 SPL FMJ-TC resulted in overpenetration three times. The .357 MAG FTX ® bullets showed to be more advantageous, because on the one hand no overpenetration occurred and on the other hand the bullets fragmented into small parts after penetration into the skull. The fragments were scattered in the brain tissue, such as the thalamus and the brain stem, and thus there is a high probability to damage the brain regions relevant for deep unconsciousness. Based on the results of this study, the use of the BigBovid in combination with the .357 MAG FTX ® bullet is found to be suitable for stunning heavy cattle. Keywords: animal welfare; concussion; desensitization; heavy bulls; slaughterin

Optimal pressure for mimicking clinical breath holding inspiratory CT in the deceased for VPMCT

Introduction Ventilated PMCT (VPMCT) has been reported to provide better quality of pulmonary structures in PMCT in adults and children. However, there are no consensus regarding optimal inflation pressure, and the practical use of VPMCT is still limited by cost of ventilation equipment. Here, we describe a simple and cost-efficient inflation-device for VPMCT and investigate optimal inflation pressure. Aim To elucidate the effect of different ventilation pressures on total lung volume and the volume of ground glass opacities (GGO), air-filled tissue, consolidations, and bronchi in VPMCT. Materials and method A precise inflation device was assembled using standard components: a back-pressure regulator, a water manometer and silicone tubing. Each case had PMCT performed at 0, 10, 20, 30 and 40 cmH2O pressure. Volumes were measured using stereology. Results 14 cases were enrolled in the study. The total lung volume increased significantly by 3612 mL (median) from 0 to 30 cmH2O (p = 0.001). The volume of consolidations was significantly reduced by 455.86 mL (median) between 0 and 30 cmH2O (p = 0.001). A significant reduction of GGO-volume of 133 mL (median) was observed at the pressure interval 30–40 cmH2O (p = 0.031), but not at lower pressures. Conclusion The constructed inflation device allowed precise and reproducible inflation of the lungs in deceased humans. We found a maximum effect of inflation at 30 cmH2O. At further inflation pressure, only the volume of GGOs decreased , but the effect was minor. For mimicking an in vivo breath-hold scan in PMCT we recommend inflation pressure of 30 cmH2O. + Graphical abstrac

Ballistic study on the penetration potential and injury potential of different bullet types in the use of a newly developed bullet shooting stunner for adequate stunning of heavy cattle

IntroductionRecently, a special bullet shooting stunner for heavy cattle has been developed that fires a bullet instead of a bolt. In the search for a suitable ammunition, the following criteria must be met: First, the energy of the bullet must be sufficient to penetrate the thick frontal bones of heavy cattle. Second, the injury potential at the corresponding penetration depth should preferably be large in order to damage brain tissue relevant to stunning. Third, the bullet must not perforate the occipital bone (over-penetration).MethodsFour different bullet types [Hornady FTX, Hydra-Shok, Black Mamba, and a common full metal jacket (FMJ) bullet] were evaluated in a series of experiments on soap blocks and removed bone plates followed by computed tomography examinations. Penetration potential was evaluated in terms of kinetic energy relative to the caliber of the bullet, i.e., mean energy density (ED). Injury potential was evaluated by the mean extent of the cavity volume (e$_{CV}$) at the relevant penetration depth of 5.5 to 7.5 cm in the soap block.ResultsAll four bullet types passed through the frontal bone plate. The ED was 17.50 J/mm$^{2}$ (Hornady FTX), 17.46 J/mm$^{2}$ (Hydra-Shok), 13.47 J/mm$^{2}$ (Black Mamba), and 13.47 J/mm$^{2}$ (FMJ). The Hornady FTX and the Hydra-Shok each fragmented heavily. The FMJ was excluded after three experiments due to over-penetrations. The e$_{CV}$ was e$_{CV}$ = 3.77 cm$^{2}$ (Hornady FTX), 2.71 cm$^{2}$ (Hydra-Shok), and 1.31 cm$^{2}$ (Black Mamba), with a significant difference (p = 0.006) between the Hornady FTX and the Black Mamba.DiscussionFor use in heavy cattle, the Hornady FTX and the Hydra-Shok are recommended due to the larger e$_{CV}$ than the Black Mamba

Time-dependent postmortem redistribution of butyrfentanyl and its metabolites in blood and alternative matrices in a case of butyrfentanyl intoxication

A fatal case of butyrfentanyl poisoning was investigated at the Zurich Institute of Forensic Medicine. At admission at the institute approx. 9 h after death (first time point, t1), femoral and heart blood (right ventricle) was collected, as well as samples from the lung, liver, kidney, spleen, muscle and adipose tissue using computed tomography (CT)-guided biopsy sampling. At autopsy (t2), samples from the same body regions were collected manually. Additionally, urine, heart blood (left ventricle), gastric content, brain samples and hair were collected. Butyrfentanyl concentrations and relative concentrations of the metabolites carboxy-, hydroxy-, nor-, and desbutyrfentanyl were determined by LC⿿MS/MS and LC-QTOF. At t1, butyrfentanyl concentrations were 66 ng/mL in femoral blood, 39 ng/mL in heart blood, 110 ng/g in muscle, 57 ng/g in liver, 160 ng/g in kidney, 3100 ng/g in lung, 590 ng/g in spleen and 550 ng/g in adipose tissue. At t2, butyrfentanyl concentration in urine was 1100 ng/mL, in gastric content 2000 ng/mL, in hair 11,000 pg/mg and brain concentrations ranged between 200⿿340 ng/g. Carboxy- and hydroxybutyrfentanyl were identified as most abundant metabolites. Comparison of t1 and t2 showed a concentration increase of butyrfentanyl in femoral blood of 120%, in heart blood of 55% and a decrease in lung of 30% within 19 h. No clear concentration changes could be observed in the other matrices. Postmortem concentration changes were also observed for the metabolites. In conclusion, butyrfentanyl seems to be prone to postmortem redistribution processes and concentrations in forensic death cases should be interpreted with caution

Diagnostic value of T1_{1}- and T2_{2}-weighted 3-Tesla MRI for postmortem detection and age stage classification of myocardial infarction

The aims of this study are to retrospectively evaluate the diagnostic value of T$_{1}$- and T$_{2}$-weighted 3-T magnetic resonance imaging (MRI) for postmortem detection of myocardial infarction (MI) in terms of sensitivity and specificity and to compare the MRI appearance of the infarct area with age stages. Postmortem MRI examinations (n = 88) were retrospectively reviewed for the presence or absence of MI by two raters blinded to the autopsy results. The sensitivity and specificity were calculated using the autopsy results as the gold standard. A third rater, who was not blinded to the autopsy findings, reviewed all cases in which MI was detected at autopsy for MRI appearance (hypointensity, isointensity, hyperintensity) of the infarct area and the surrounding zone. Age stages (peracute, acute, subacute, chronic) were assigned based on the literature and compared with the age stages reported in the autopsy reports. The interrater reliability between the two raters was substantial (κ = 0.78). Sensitivity was 52.94% (both raters). Specificity was 85.19% and 92.59%. In 34 decedents, autopsy identified an MI (peracute: n = 7, acute: n = 25, chronic: n = 2). Of 25 MI classified as acute at autopsy, MRI classified peracute in four cases and subacute in nine cases. In two cases, MRI suggested peracute MI, which was not detected at autopsy. MRI could help to classify the age stage and may indicate the area for sampling for further microscopic examination. However, the low sensitivity requires further additional MRI techniques to increase the diagnostic value

Added value of ultra-short echo time and fast field echo using restricted echo-spacing MR imaging in the assessment of the osseous cervical spine

PURPOSE To evaluate the added value of ultra-short echo time (UTE) and fast field echo resembling a CT using restricted echo-spacing (FRACTURE) MR sequences in the assessment of the osseous cervical spine using CT as reference. MATERIALS AND METHODS Twenty-seven subjects underwent postmortem CT and MRI within 48 h. Datasets were anonymized and analyzed retrospectively by two radiologists. Morphological cervical spine alterations were rated on CT, UTE and FRACTURE images. Afterward, neural foraminal stenosis was graded on standard MR and again after viewing additional UTE/FRACTURE sequences. To evaluate interreader and intermodality reliability, intra-class correlation coefficients (ICC) and for stenosis grading Wilcoxon-matched-pairs testing with multiple comparison correction were calculated. RESULTS Moderate interreader reliability (ICC = 0.48-0.71) was observed concerning morphological findings on all modalities. Intermodality reliability was good between modalities regarding degenerative vertebral and joint alterations (ICC = 0.69-0.91). Compared to CT neural stenosis grades were more often considered as nonsignificant on all analyzed MR sequences. Neural stenosis grading scores differed also significantly between specific bone imaging sequences, UTE and FRACTURE, to standard MR sequences. However, no significant difference was observed between UTE and FRACTURE sequences. CONCLUSION Compared to CT as reference, UTE or FRACTURE sequence added to standard MR sequences can deliver comparable information on osseous cervical spine status. Both led to changes in clinically significant stenosis gradings when added to standard MR, mainly reducing the severity of neural foramina stenosis

The influence of rotator cuff tear type and weight bearing on shoulder biomechanics in an ex vivo simulator experiment

Glenohumeral biomechanics after rotator cuff (RC) tears have not been fully elucidated. This study aimed to investigate the muscle compensatory mechanism in weight-bearing shoulders with RC tears and asses the induced pathomechanics (i.e., glenohumeral translation, joint instability, center of force (CoF), joint reaction force). An experimental, glenohumeral simulator with muscle-mimicking cable system was used to simulate 30° scaption motion. Eight fresh-frozen shoulders were prepared and mounted in the simulator. Specimen-specific scapular anthropometry was used to test six RC tear types, with intact RC serving as the control, and three weight-bearing loads, with the non-weight-bearing condition serving as the control. Glenohumeral translation was calculated using instantaneous helical axis. CoF, muscle forces, and joint reaction forces were measured using force sensors integrated into the simulator. Linear mixed effects models (RC tear type and weight-bearing) with random effects (specimen and sex) were used to assess differences in glenohumeral biomechanics. RC tears did not change the glenohumeral translation (p > 0.05) but shifted the CoF superiorly (p ≤ 0.005). Glenohumeral translation and joint reaction forces increased with increasing weight bearing (p < 0.001). RC and deltoid muscle forces increased with the presence of RC tears (p ≤ 0.046) and increased weight bearing (p ≤ 0.042). The synergistic muscles compensated for the torn RC tendons, and the glenohumeral translation remained comparable to that for the intact RC tendons. However, in RC tears, the more superior CoF was close to where glenoid erosion occurs in RC tear patients with secondary osteoarthritis. These findings underscore the importance of early detection and precise management of RC tears