title: Detection and volume estimation of artificial hematomas in the subcutaneous fatty tissue: comparison of different MR sequences at 3.0 T.
abstract: In legal medicine, reliable localization and analysis of hematomas in subcutaneous fatty tissue is required for forensic reconstruction. Due to the absence of ionizing radiation, magnetic resonance imaging (MRI) is particularly suited to examining living persons with forensically relevant injuries. However, there is limited experience regarding MRI signal properties of hemorrhage in soft tissue. The aim of this study was to evaluate MR sequences with respect to their ability to show high contrast between hematomas and subcutaneous fatty tissue as well as to reliably determine the volume of artificial hematomas. Porcine tissue models were prepared by injecting blood into the subcutaneous fatty tissue to create artificial hematomas. MR images were acquired at 3T and four blinded observers conducted manual segmentation of the hematomas. To assess segmentability, the agreement of measured volume with the known volume of injected blood was statistically analyzed. A physically motivated normalization taking into account partial volume effect was applied to the data to ensure comparable results among differently sized hematomas. The inversion recovery sequence exhibited the best segmentability rate, whereas the T1T2w turbo spin echo sequence showed the most accurate results regarding volume estimation. Both sequences led to reproducible volume estimations. This study demonstrates that MRI is a promising forensic tool to assess and visualize even very small amounts of blood in soft tissue. The presented results enable the improvement of protocols for detection and volume determination of hemorrhage in forensically relevant cases and also provide fundamental knowledge for future in-vivo examinations.
authors.affiliation: Institute of Forensic Medicine, Medical University of Graz, Universitaetsplatz 4/II, A-8010, Graz, Austria. kathrin.ogris@medunigraz.at.|Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria. kathrin.ogris@medunigraz.at.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Ogris
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|Institute for Biomedical Engineering, Graz University of Technology, Graz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petrovic
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Scheicher
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|BioTechMed-Graz, Graz, Austria.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sprenger
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|BioTechMed-Graz, Graz, Austria.|Institute for Computer Graphics and Vision, Graz University of Technology, Graz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Urschler
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|Division of Neuroradiology, Vascular and Interventional Radiology, Department of Radiology, Medical University of Graz, Graz, Austria.
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Hassler
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|Institute of Forensic and Traffic Medicine, University of Heidelberg, Heidelberg, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Yen
authors.affiliation: Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.|Institute of Forensic Medicine, Health Department Basel, University Basel, Basel, Switzerland.
authors.forename: Eva
authors.initials: E
authors.lastname: Scheurer
mesh_terms: D000818:Animals; D049429:Forensic Pathology; D006406:Hematoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D040521:Subcutaneous Tissue / Q000000981:diagnostic imaging* / Q000473:pathology; D013552:Swine
keywords: 3.0 T MRI; Forensic medicine; Hematoma; Porcine tissue model; Subcutaneous fatty tissue; Volume measurement