Publications by authors named "Christine Bruguier"

7 Publications

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Impact of increasing levels of adaptive statistical iterative reconstruction on image quality in oil-based postmortem CT angiography in coronary arteries.

Int J Legal Med 2021 Feb 24. Epub 2021 Feb 24.

Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, D-40225, Dusseldorf, Germany.

Introduction: Postmortem multi-detector computed tomography (PMCT) has become an important part in forensic imaging. Modern reconstruction techniques such as iterative reconstruction (IR) are frequently used in postmortem CT angiography (PMCTA). The image quality of PMCTA depends on the strength of IR. For this purpose, we aimed to investigate the impact of different advanced IR levels on the objective and subjective PMCTA image quality.

Material And Methods: We retrospectively analyzed the coronary arteries of 27 human cadavers undergoing whole-body postmortem CT angiography between July 2017 and March 2018 in a single center. Iterative reconstructions of the coronary arteries were processed in five different level settings (0%; 30%; 50%; 70%; 100%) by using an adaptive statistical IR method. We evaluated the objective (contrast-to-noise ratio (CNR)) and subjective image quality in several anatomical locations.

Results: Our results demonstrate that the increasing levels of an IR technique have relevant impact on the image quality in PMCTA scans in forensic postmortem examinations. Higher levels of IR have led to a significant reduction of image noise and therefore to a significant improvement of objective image quality (+ 70%). However, subjective image quality is inferior at higher levels of IR due to plasticized image appearance.

Conclusion: Objective image quality in PMCTA progressively improves with increasing level of IR with the best CNR at the highest IR level. However, subjective image quality is best at low to medium levels of IR. To obtain a "classic" image appearance with optimal image quality, PMCTAs should be reconstructed at medium levels of IR.
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http://dx.doi.org/10.1007/s00414-021-02530-1DOI Listing
February 2021

Oleic Acid (OA), A Potential Dual Contrast Agent for Postmortem MR Angiography (PMMRA): A Pilot Study.

Curr Med Sci 2020 Aug 29;40(4):786-794. Epub 2020 Aug 29.

Dian Research Center for Postmortem Imaging & Angiography, Beijing, 100192, China.

Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography (PMMRA). However, in this emerging field, the number of suitable kinds of liquid is still very limited. The objective of this research is to compare MR images of oleic acid (OA) with paraffin oil (PO) in vitro and in ex situ animal hearts, in order to evaluate the feasibility to use OA as a novel contrast agent for PMMRA. In vitro, OA, PO and water (control) were introduced into three tubes separately and Tweighted-spin echo (Tw-SE) and Tw-SE images were acquired on a 1.5T MR scanner. In the second experiment, OA and PO were injected into left coronary artery (LCA) and left ventricle (LV) of ex situ bovine hearts and their Tw-SE, Tw-SE, Tw-multipoint Dixon (Tw-mDixon) and 3DTw-mDixon images were acquired. The overall results indicate that OA may have a potential to be used as a dual (T and T based) contrast agent for PMMRA when proper sequence parameters are utilized. However, as the pilot study was based on limited number of animal hearts, more researches using OA in cadavers are needed to validate our findings.
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http://dx.doi.org/10.1007/s11596-020-2244-7DOI Listing
August 2020

Neck-MRI experience for investigation of survived strangulation victims.

Forensic Sci Res 2020 7;5(2):113-118. Epub 2019 May 7.

University Center of Legal Medicine Lausanne - Geneva, University Hospital Lausanne, Lausanne, Switzerland.

For the medicolegal evaluation of victims of survived strangulation, a neck-magnetic resonance imaging (MRI) can be performed for assessing lesions in the inner soft tissues (fat, muscles or lymph nodes, for example). In our institute, such MRI examinations have been performed for a test period of 4 years with the aim of evaluating the use of this tool by forensic pathologists and identifying medicolegal indicators for the performance of neck-MRI in surviving victims of strangulation. We retrospectively reviewed medicolegal reports from all victims examined during the test period. We extracted objective lesions (e.g. petechiae, bruising and abrasions) and reported clinical symptoms (e.g. vision disorder, dysphasia) from the reports. These findings were compared to those reported from the neck-MRI. In total, 112 victims were clinically examined after suspected strangulation. Eleven of these victims underwent an MRI examination of the neck. Eighty-four of the victims presented objective lesions during the clinical examination, with eight showing signs of both petechiae and bruising. Neck-MRI was performed in four of these eight victims and three of them showed lesions visible in MRI. Of 76 victims with bruising as the only objective finding, 66 victims described clinical symptoms. Of those 66 victims, seven were examined by MRI and two demonstrated lesions in MRI. When MRI was performed, relevant findings were detected in 45% of the cases. This leads to the suspicion that many more findings could have been detected in the other victims, if an MRI had been performed in those cases. Our results lead us to the conclusion that an MRI examination of victims of suspected strangulation is useful, and strict indications for its application should be established.
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http://dx.doi.org/10.1080/20961790.2019.1592314DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476612PMC
May 2019

Temperature dependence of viscosity, relaxation times (T, T) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA).

Int J Legal Med 2017 May 29;131(3):739-749. Epub 2016 Nov 29.

BioTechMed-Graz, Graz, Austria.

Developments in post-mortem imaging increasingly focus on addressing recognised diagnostic weaknesses, especially with regard to suspected natural deaths. Post-mortem MR angiography (PMMRA) may offer additional diagnostic information to help address such weaknesses, specifically in the context of sudden cardiac death. Complete filling of the coronary arteries and acceptable contrast with surrounding tissue are essential for a successful approach to PMMRA. In this work, the suitability of different liquids for inclusion in a targeted PMMRA protocol was evaluated. Factors influencing cooling of paraffinum liquidum + Angiofil® (6 %) in cadavers during routine multiphase post-mortem CT angiography were investigated. The temperature dependence of dynamic viscosity (8-20 °C), longitudinal (T) and transverse (T) relaxation (1-23 °C) of the proposed liquids was quadratically modelled. The relaxation behaviour of these liquids and MR scan parameters were further investigated by simulation of a radiofrequency (RF)-spoiled gradient echo (GRE) sequence to estimate potentially achievable contrast between liquids and post-mortem tissue at different temperatures across a forensically relevant temperature range. Analysis of the established models and simulations indicated that based on dynamic viscosity (27-33 mPa · s), short T relaxation times (155-207 ms) and a minimal temperature dependence over the investigated range of these parameters, paraffin oil and a solution of paraffin oil + Angiofil® (6 %) would be most suitable for post-mortem reperfusion and examination in MRI.
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http://dx.doi.org/10.1007/s00414-016-1482-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5388705PMC
May 2017

Performance of post-mortem CT compared to autopsy in children.

Int J Legal Med 2016 Jul 24;130(4):1089-1099. Epub 2016 May 24.

University Center of Legal Medicine Lausanne-Geneva, University Hospital of Lausanne, Chemin de la Vulliette 4, 1000, Lausanne 25, Switzerland.

Introduction: Radiological techniques such as non-enhanced post-mortem computed tomography (PMCT) play an increasingly important role in death investigations, especially in cases of non-medicolegal context of death, where the consent of the next of kin is required to perform autopsy. Such consent is often difficult to obtain for deceased children, and radiological methods may be an acceptable alternative. The aim of our study was to evaluate the performance of PMCT explorations compared to medicolegal conventional autopsies in children and its potential usefulness in non-medicolegal situations.

Methods: We retrospectively reviewed a group of 26 children aged 0-12 years who died of different causes, which were investigated by both conventional autopsy and PMCT. We compared the findings extracted from radiological and autopsy reports. All findings were grouped according to their importance with respect to cause of death and to the anatomical structure they covered: organs, vascular system, soft tissue, and skeletal system.

Results: A significantly larger number of findings were detected by autopsy compared to PMCT. Autopsy proved to be superior to PMCT, notably at detecting organ, soft tissue, and vascular findings, while PMCT was superior at detecting bone findings. However, no statistically significant differences were found between the methods concerning the essential findings used to define the cause of death.

Conclusions: In children, PMCT was less sensitive than conventional autopsy for detecting general findings. However, most essential findings were detected by both methods. PMCT was superior to autopsy for the detection of bone lesions in children.

Advances In Knowledge: Up to today, very rare literature exists concerning PMCT in children, especially in a forensic setting. This article investigates the advantages and limitations of PMCT compared to autopsy in a unique study group and discusses possibilities for future developments.
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http://dx.doi.org/10.1007/s00414-016-1370-zDOI Listing
July 2016

Tearing of the left iliac vessels in lumbar surgery revealed by multiphase post-mortem CT-angiography (MPMCTA).

Leg Med (Tokyo) 2016 May 22;20:44-8. Epub 2016 Apr 22.

Center of Legal Medicine Lausanne-Geneva, University of Lausanne, Chemin de la Vulliette 4, CH-1000 Lausanne 25, Switzerland.

Lumbar surgery is regularly applied in cases of discal hernia and acquired lumbar stenosis. In this report, we present a case of a laceration in the left common iliac artery and iliac vein during a lumbar surgery and discuss the literature concerning this kind of event. In the present case, the surgical procedure was followed by a sudden decrease in blood pressure, and the surgeon discovered an intra-abdominal haemorrhage that led to the patient's death. Postmortem investigation confirmed the intra-abdominal haemorrhage and revealed a laceration of the proximal portion of the left common iliac artery and left iliac vein. The source of bleeding could be detected especially thanks to multi-phase postmortem CT angiography (MPMCTA), which was performed prior to autopsy. We also found a haemorrhagic path through the intervertebral disc between the L4-L5 vertebrae, caused by the surgeon's instrument (pituitary rongeur). To date, a few cases have been described of iatrogenic death resulting from a tear in the iliac vessels during lumbar surgery, but not from the postmortem perspective. Such investigations have recently been modernized thanks to the introduction of forensic imaging. In particular, MPMCTA offers new possibilities in postmortem investigations and can be considered the new gold standard for investigating deaths related to medical intervention. Here we describe the first case of a death during lumbar surgery using this new method.
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http://dx.doi.org/10.1016/j.legalmed.2016.04.003DOI Listing
May 2016

The forensic radiographer: a new member in the medicolegal team.

Am J Forensic Med Pathol 2012 Mar;33(1):30-6

University Center of Legal Medicine Lausanne-Geneva, University of Lausanne, Rue du Bugnon 21, Lusanne, Switzerland.

Multidetector computed tomography is becoming more widespread in forensic medicine. In most services, autopsy assistants perform the radiological examination. We introduced professional radiographers into the legal medicine service and hypothesized they would also be able to take over duties currently reserved for other specialists. The aims of this study were to evaluate if radiographers could be trained as "forensic radiographers" by (1) integrating graduated medical radiographers into the legal medicine service, (2) investigating the advantages of this collaboration, and (3) defining the duties of the forensic radiographers.The study was performed prospectively on a group of 8 recruited radiographers who underwent a testing period with special training. They learned the basics of medicolegal case treatment, the autonomous execution of postmortem computed tomography angiography, and postprocessing of data. Seven of 8 radiographers finished the training and were integrated into our service. Although all radiographers were able to fulfill the duties demanded after the training period, some radiographers could not enter or complete the program because they were unable to work with dead bodies.Our study presents the advantages of integrating radiographers into the medicolegal team and proposes how to train the forensic radiographers. In addition, the duties and responsibilities of these new specialists are defined.
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http://dx.doi.org/10.1097/PAF.0b013e31820c6aa3DOI Listing
March 2012