Webb Bridgette, Widek Thomas, Scheicher Sylvia, Schwark Thorsten, Stollberger Rudolf
Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria.
Medical University of Graz, Institute of Forensic Medicine, Graz, Austria.
Int J Legal Med. 2018 Mar;132(2):579-587. doi: 10.1007/s00414-017-1763-7. Epub 2018 Jan 18.
As the implementation of minimally invasive imaging techniques in both forensic and pathological practice increases, research in this area focuses on addressing recognised diagnostic weaknesses of current approaches. Assessment of sudden cardiac death (SCD) can be considered one such area in which post-mortem imaging still shows diagnostic weaknesses. We hypothesise that magnetic resonance imaging (MRI) with an angiographic adjunct may improve the visualisation and interpretation of cardiac pathologies in a post-mortem setting. To systematically investigate this hypothesis, selected perfusates (paraffin oil, Gadovist®;-doped physiological solution and polyethylene glycol (PEG)) were injected into the left anterior descending (LAD) artery of ex situ porcine hearts to assess the visualisation of perfusates in MRI as well as their intravascular retention over 12 h. Morphological images were acquired and quantitative T maps were generated from inversion recovery data. Visualisation of vascular structure and image quality were assessed using signal-to-noise and contrast-to-noise ratios. Intravascular retention was assessed both visually and statistically using a volume of interest (VOI) approach to analyse significant changes in signal intensity in and around the filled LAD artery, as well as changes in the longitudinal relaxation time (T) in adjacent myocardium. In addition to presenting possible mechanisms explaining perfusate extravasation given the increased permeability of post-mortem vessels, the potential diagnostic consequences of this phenomenon and the importance of contrast stability and extended intravascular retention are discussed. In light of our findings and these considerations, paraffin oil emerged as the preferred perfusate for use in post-mortem MR angiography.
随着微创成像技术在法医和病理学实践中的应用不断增加，该领域的研究重点是解决当前方法公认的诊断弱点。心脏性猝死（SCD）的评估可被视为这样一个领域，其中尸检成像仍显示出诊断弱点。我们假设，结合血管造影辅助的磁共振成像（MRI）可能会改善尸检环境中心脏病理的可视化和解读。为了系统地研究这一假设，将选定的灌注剂（石蜡油、钆布醇掺杂的生理溶液和聚乙二醇（PEG））注入离体猪心脏的左前降支（LAD）动脉，以评估灌注剂在MRI中的可视化情况以及它们在12小时内的血管内滞留情况。采集形态学图像，并从反转恢复数据生成定量T图。使用信噪比和对比噪声比评估血管结构的可视化和图像质量。使用感兴趣体积（VOI）方法在视觉和统计学上评估血管内滞留情况，以分析充盈的LAD动脉及其周围信号强度的显著变化，以及相邻心肌纵向弛豫时间（T）的变化。除了提出可能解释尸检血管通透性增加导致灌注剂外渗的机制外，并讨论了这一现象的潜在诊断后果以及对比剂稳定性和延长血管内滞留的重要性。根据我们的研究结果和这些考虑因素，石蜡油成为尸检磁共振血管造影中首选的灌注剂。
