PECULIARITIES OF THE IDENTIFICATION OF DIFFERENT TYPES OF TISSUES DURING 3D-RECONSTRUCTION OF HUMAN MICROSCOPIC STRUCTURES

3D reconstruction is an informative, objective method of morphological research that consists in transforming a seriesof successive sections (histological, macroscopic, anatomical sections, computed tomography (CT), etc.) into a virtual threedimensional (digital) image that can be studied in diff erent projections and measure volumes, areas, diameters, angles, save, copy, edit.The aim of the study. The aim of this work was to compare the eff ectiveness of 3D reconstruction methods of various tissuesand microscopic anatomical structures of the human body in the prenatal period of development.Material and methods. The research was carried out on 6 series of consecutive histological sections of human embryos atthe age of 4 to 6 weeks of intrauterine development (IUD), 15 samples of organ complexes of the head, limbs and trunk of human fetuses at the age of 7 to 12 weeks of IUD, human fetuses aged 4-9 months of IUD by the method of making histological (5), as well as histotopographic sections (10) directly from the paraffi n block and their digitization, and 14 CT of human fetuses aged 4 to 9 months of IUD. The studies were conducted in accordance with the most important regulations of the resolution of the First National Bioethics Congress «General Ethical Principles of Experiments on Animals» (2001), ICH GCP (1996), the European Union Convention on Human Rights and Biomedicine (April 4, 1997) and the European Convention for the Protection of Vertebrate Animals used in Experimental and Other Scientifi c Research (March 18, 1986). 1997) and the European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientifi c Purposes (18.03.1986), the Declaration of Helsinki on Ethical Principles for Medical Research Involving Human Subjects (1964-2008), EU Directives № 609 (24.11.1986), Orders of the Ministry of Health of Ukraine № 690 dated 23.09.2009, № 944 dated 14.12.2009, № 616 dated 03.08.2012. The work is carried out within the framework of the initiative research work of the Department of Histology, Cytology and Embryology of the Bukovinian State Medical University «Structural and functional peculiarities of tissues and organs in ontogenesis, regularities of variant, constitutional, gender, age and comparative human morphology». State registration number: 0121U110121. Terms of execution: 01.2021-12.2025.Results. 3D reconstruction of series of consecutive histological sections is eff ective for the study of embryonic specimens,organ complexes of prefetuses and certain microscopic structures of human fetuses due to easy identifi cation of histological structures, however, it is necessary to improve the methods of alignment of histological sections both in the correct sequence of the series and in the natural position. 3D reconstruction of histotopographic sections is recommended for the study of specimens of organ complexes of human prefetuses and fetuses. 3D reconstruction of CT sections is an eff ective and highly accurate tool for the study of X-ray contrast anatomical structures in the fetal period of IUD (bone tissue, contrasting blood vessels), allows using a certain research algorithm to detect and measure ossifi cation centers and syntopy of blood vessels with bones.Conclusions. For wide application in morphology, the method of 3D reconstruction requires technical improvement of thesoftware- hardware complex for reconstruction, namely: automation of segmentation of sections, as well as improvement ofmethods of polychrome marking of anatomical structures for their clear diff erentiation.