Assessing Kidney Tissue Density Changes in Rats with Hyperlipidemia Using Micro-CT

Introduction. Computed X-ray microtomography (micro-CT) enables getting the three-dimensional images of microscopic structures without damaging them, which makes this method widely implemented in biomedicine. Regarding the application of micro-CT in veterinary medicine, its potential in assessing morphological changes in internal organs of animals with pathologies has not yet been used at full scale. For example, there are no enough data on the capacity of microtomography in studying pathological processes in kidneys of animals. The aim of the present study is to assess the pathological changes in the density and morphology of kidney tissue in laboratory rats with hyperlipidemia using micro-CT.

Materials and Methods. The experiment was conducted at DSTU from 2021 to 2024 and involved 40 male Wistar rats divided into 5 groups: 4 experimental and 1 control. During the experiment, the experimental groups were fed a hyperlipidemic diet; the control group received only standard feed-stuff. Kidneys were taken from decapitated animals on 30^th, 120^th, 150^th, and 180^th day, and samples were prepared for scanning with a Zeiss Xradia Versa 520 micro-CT scanner at 80 kV and voxel size of 20 μm. The efficiency of micro-CT was assessed by the quality of 3D reconstruction and detected changes in kidney tissue density and morphology at different stages of hyperlipidemia.

Results. Microtomograms of kidneys of rats in the experiment allowed for detailed visualization of the organ’s morphology, including renal cortex and medulla, as well as vasculature. Quantitative data on changes in tissue density were obtained, and differences in kidney structure were distinguished between the normal (in control group) and pathological conditions (in experimental groups with various degrees of hyperlipidemia).

Discussion and Conclusion. Micro-CT method has demonstrated high accuracy and informative value in analysing kidney tissue condition in rats and proved its efficiency in early diagnostics of pathological changes in these internal organs, as well as in dynamic monitoring of disease. Among the constraints of this method, the following aspects can be noted: the high cost of equipment, low sensitivity to soft tissues in the absence of contrast-enhancement, and the need for specialized skills to interpret the images.

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