title: Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA).
abstract: 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 T1relaxation 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.
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria. bridgette.webb@cfi.lbg.ac.at.|Institute of Forensic Medicine, Medical University Graz, Graz, Austria. bridgette.webb@cfi.lbg.ac.at.|BioTechMed-Graz, Graz, Austria. bridgette.webb@cfi.lbg.ac.at.
authors.forename: Bridgette
authors.initials: B
authors.lastname: Webb
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria.|BioTechMed-Graz, Graz, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Widek
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria.|BioTechMed-Graz, Graz, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Neumayer
authors.affiliation: University Center of Legal Medicine, Lausanne-Geneva, University of Lausanne, Lausanne, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Bruguier
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria.|BioTechMed-Graz, Graz, Austria.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Scheicher
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria.|BioTechMed-Graz, Graz, Austria.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sprenger
authors.affiliation: University Center of Legal Medicine, Lausanne-Geneva, University of Lausanne, Lausanne, Switzerland.
authors.forename: Silke
authors.initials: S
authors.lastname: Grabherr
authors.affiliation: Ludwig Boltzmann Institute for Clinical Forensic Imaging, Universitätsplatz 4/2., Graz, 8010, Austria.|Institute of Forensic Medicine, Medical University Graz, Graz, Austria.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Schwark
authors.affiliation: BioTechMed-Graz, Graz, Austria.|Institute of Medical Engineering, Graz University of Technology, Graz, Austria.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Stollberger
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D002102:Cadaver; D003287:Contrast Media / Q000737:chemistry*; D005260:Female; D049429:Forensic Pathology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009821:Oils; D010232:Paraffin; D013696:Temperature; D014783:Viscosity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009821:Oils; D010232:Paraffin; C015418:paraffin oils
keywords: Angiography; MRI; Post-mortem; Quantitative; Simulation; Temperature