THE USE OF THE DIFFUSE TOMOGRAPHY METHOD FOR RESEARCHING THE TIME OF HEMORRHAGE FORMATION IN THE SUBSTANCE OF THE HUMAN BRAIN

Abstract

As traumatic brain injury (TBI) causes the highest level of mortality and disability among all types of mechanical injuries, forensic authorities pay a lot of attention to investigating the circumstances of its receipt. In turn, in order to reproduce the events preceded death from TBI, investigative bodies need to know as precisely as possible the time of hemorrhage formation, which can often be close to the moment of death. Therefore, scientists in the fi eld of forensic medicine are working on the development of express methods that would allow to geta quick and objective answer to the question of establishing the age of the formation of a hemorrhage in the substance of the human brain. The purpose and tasks of the research. To develop, within the framework of the statistical analysis of optical anisotropy maps, universal forensic medical criteria for the determination of time of haemorrages formation due to TBI, cerebral infarction of ischemic and hemorrhagic genesis by the method of diff use tomography of the polycrystalline component of native histological sections of the brain with algorithmic reproduction of fl uctuations in the value of linear birefringence. Research materials and methods. Native slices of human brain from the parietal area were taken for the study from the dead with a known time of hemorrhage formation from 1 to 7 days, according to medical documents. The cause of death was traumatic hemorrhage – II group (n=100), ischemic cerebral infarction – III group (n=110), non-traumatic hemorrhage – IV group (n=105), acute coronary insuffi ciency – I group – control (n=20). In the laboratory of the Institute of Physical, Technical and Computer Sciences of the Yuriy Fedkovich Chernivtsi National University, studies of the obtained samples were carried out using a Stokes polarimeter by the diff use tomography method of reproduction of fl uctuations of linear birefringence (FLB). The evaluation of the obtained results was carried out by means of statistical (statistical moments of the 1st – 4th orders were determined) and informational analysis (the operational characteristics of the strength of the methods were determined: sensitivity, specifi city and balanced accuracy). The study was carried out in compliance with the main provisions of the GCP (1996), the Council of Europe Convention on Human Rights and Biomedicine (from 04.04.1997), the Helsinki Declaration of the World Medical Association on the ethical principles of conducting scientifi c medical research with human participation (1964-2013), order of the Ministry of Health of Ukraine No. 690 dated 23.09.2009, No. 616 dated 03.08.2012 at the Department of Forensic Medicine and Medical Law of Bukovinian State Medical University as a fragment of the complex research work of the Department of Forensic Medicine and Medical Law «Using modern morphological and physical methods for diagnosing the time and cause of death, the occurrence of bodily injuries, the development of their remote and immediate consequences in order to solve the urgent tasks of law enforcement agencies and current issues of forensic science and practice» 0123U101978. The author is a co-performer of the research work. Research results. As part of the statistical analysis of the data of the diff use tomography method, universal forensic criteria (markers) for determining the age of the formation of hemorrhages were established – asymmetry and excess, which characterize the temporal transformation of the coordinate distributions of the random values of the optical anisotropy parameters for cases of TBI, death due to brain infarction of ischemic and hemorrhagic genesis. It was established that degenerative- dystrophic changes and necrotic destruction of the polycrystalline structure formed by optically active spatially structured protein fi bers of nervous tissue are objectively manifested in statistically reliable linear (within 120 hours) changes in the magnitude of the statistical moments of the 3rd and 4th orders, which characterize the asymmetry and excess of distributions of random values of the FLB value of fi brillar networks with the increasing age of the formation of hemorrhages. Conclusions. Statistical analysis of temporal transformation of maps of optical anisotropy of nervous tissue revealed universal criteria (statistical moments of the 3rd and 4th orders) for forensic assessment of the age of formation of hemorrhages of various genesis. By monitoring the time change in the magnitude of statistical moments of the 3rd and 4th orders, which characterize the asymmetry and excess of distributions of random values of the magnitude of fl uctuations in the manifestations of optical anisotropy of nervous tissue, were determine the duration (120 hours) and the ranges of linear changes in the values of the following universal detection parameters of occurrence of hemorrhages in case of TBI (SM4:0,33 − 3,31); brain infarction of ischemic genesis (SM3:0,33 − 2,21; SM4:0,48 − 3,5) and brain infarction of hemorrhagic genesis (SM3:0,28 − 1,96; SM4:0,39 − 2,7). Diagnostic accuracy is 1.5 h ± 20 min.

Keywords

• Traumatic Brain Injury; Forensic Medicine; Time of Formation of Hemorrhage; Diff use Tomography