Postmortem magnetic resonance imaging of the heart ex situ: development of technical protocols

Bruguier, Christine; Egger, Coraline; Vallée, Jean‐Paul; Grimm, Jochen; Boulanger, X.; Jackowski, Christian; Mangin, Patrice; Grabherr, Silke

doi:10.1007/s00414-014-1058-1

Cited by 22 publications

(11 citation statements)

References 26 publications

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“…The technical feasibility of PMMRA was demonstrated using a small cohort; however, sedimentation problems negatively affected image quality [4, 17]. A PMMRA acquisition protocol for ex situ hearts using a lipophilic contrast agent mixture (paraffin oil and Angiofil®) can also be found in the literature [18]; however, to our knowledge, a systematic evaluation of potentially suitable perfusates and imaging protocols in the context of PMMRA has not yet been undertaken.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA)

et al. 2016

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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 (T1) and transverse (T2) 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 T1 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.Electronic supplementary materialThe online version of this article (doi:10.1007/s00414-016-1482-5) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA)

et al. 2016

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“…Neither a clinical radiologist nor an expert in postmortem examination may have those competences, which have to be developed in a common approach between those two different specialties. Some examinations such as PMA require specific material and techniques in order to obtain images comparable to clinical angiographic images (Table 1) [3][4][5]15,17,18,23,31,54,55,78,[82][83][84][85][86][87].…”

Section: Discussionmentioning

confidence: 99%

Postmortem imaging as a complementary tool for the investigation of cardiac death

Michaud

Genet

Sabatasso

et al. 2019

Forensic Sciences Research

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In the past 2 decades, modern radiological methods, such as multiple detector computed tomography (MDCT), MDCT-angiography, and cardiac magnetic resonance imaging (MRI) were introduced into postmortem practice for investigation of sudden death (SD), including cases of sudden cardiac death (SCD). In forensic cases, the underlying cause of SD is most frequently cardiovascular with coronary atherosclerotic disease as the leading cause. There are many controversies about the role of postmortem imaging in establishing the cause of death and especially the value of minimally invasive autopsy techniques. This paper discusses the state of the art for postmortem radiological evaluation of the heart compared to classical postmortem examination, especially in cases of SCD. In SCD cases, postmortem CT is helpful to estimate the heart size and to visualize haemopericardium and calcified plaques and valves, as well as to identify and locate cardiovascular devices. Angiographic methods are useful to provide a detailed view of the coronary arteries and to analyse them, especially regarding the extent and location of stenosis and obstruction. In postsurgical cases, it allows verification and documentation of the patency of stents and bypass grafts before opening the body. Postmortem MRI is used to investigate soft tissues such as the myocardium, but images are susceptible to postmortem changes and further work is necessary to increase the understanding of these radiological aspects, especially of the ischemic myocardium. In postsurgery cases, the value of postmortem imaging of the heart is reportedly for the diagnostic and documentation purposes. The implementation of new imaging methods into routine postmortem practice is challenging, as it requires not only an investment in equipment but, more importantly, investment in the expertise of interpreting the images. Once those requirements are implemented, however, they bring great advantages in investigating cases of SCD, as they allow documentation of the body, orientation of sampling for further analyses and gathering of other information that cannot be obtained by conventional autopsy such as a complete visualization of the vascular system using postmortem angiography. KEY POINTSThere are no established guidelines for the interpretation of postmortem imaging examination of the heart At present, postmortem imaging methods are considered as less accurate than the autopsy for cardiac deaths Postmortem imaging is useful as a complementary tool for cardiac deaths There is still a need to validate postmortem imaging in cardiac deaths by comparing with autopsy findings ARTICLE HISTORY

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“…Nevertheless, the development of the best MRI contrast agent for postmortem or ex vivo studies remains a challenge (Bruguier et al. ; Grabherr et al. ).…”

Section: Discussionmentioning

confidence: 99%

“…Angiofil ® (Fumedica, Muri, Switzerland) enabled detailed vascular assessment and revealed the utility oily contrast agent for postmortem MRI imaging, providing complete gross anatomic diagnoses similar to autopsy (Bruguier et al. ). However, this preparation does not harden, making it impossible to dissect after imaging.…”

Section: Discussionmentioning

confidence: 99%

“… For ex vivo MRI study without gross dissection, oily contrast agent should be used, such as Angiofil ® (Bruguier et al. ) or any oily agent. For ex vivo CT study without gross dissection, a mixture of agar or gelatin and barite should be used, since it is easy to inject although difficult to dissect. For ex vivo study combining MRI and CT without gross dissection, a mixture of agar or gelatin, gadobutrol and barite should be used.…”

Section: Discussionmentioning

confidence: 99%

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A guide for effective anatomical vascularization studies: useful ex vivo methods for both CT and MRI imaging before dissection

et al. 2017

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The objective of this study was to develop a simple and useful injection protocol for imaging cadaveric vascularization and dissection. Mixtures of contrast agent and cast product should provide adequate contrast for two types of ex vivo imaging (MRI and CT) and should harden to allow gross dissection of the injected structures. We tested the most popular contrast agents and cast products, and selected the optimal mixture composition based on their availability and ease of use. All mixtures were first tested in vitro to adjust dilution parameters of each contrast agent and to fine-tune MR imaging acquisition sequences. Mixtures were then injected in 24 pig livers and one human pancreas for MR and computed tomography (CT) imaging before anatomical dissection. Colorized latex, gadobutrol and barite mixture met the above objective. Mixtures composed of copper sulfate (CuSO 4 ) gadoxetic acid (for MRI) and iodine (for CT) gave an inhomogeneous signal or extravasation of the contrast agent. Agar did not harden sufficiently for gross dissection but appears useful for CT and magnetic resonance imaging (MRI) studies without dissection. Silicone was very hard to inject but achieved the goals of the study. Resin is particularly difficult to use but could replace latex as an alternative for corrosion instead of dissection. This injection protocol allows CT and MRI images to be obtained of cadaveric vascularization and anatomical casts in the same anatomic specimen. Post-imaging processing software allow easy 3D reconstruction of complex anatomical structures using this technique. Applications are numerous, e.g. surgical training, teaching methods, postmortem anatomic studies, pathologic studies, and forensic diagnoses.

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Postmortem magnetic resonance imaging of the heart ex situ: development of technical protocols

Cited by 22 publications

References 26 publications

Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA)

Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA)

Postmortem imaging as a complementary tool for the investigation of cardiac death

A guide for effective anatomical vascularization studies: useful ex vivo methods for both CT and MRI imaging before dissection

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