X-ray computer densitometry in the diagnosis of fat hepatosis

Currently, the problem of reducing the risk of developing fat liver hepatosis from exposure to household and industrial toxicants among the working-age population continues to be an important medical and social problem, since not timely diagnosis of the disease can lead to its progressive course with the development of inflammatory changes, necrosis and liver fibrosis up to cirrhosis and hepatocellular cancer. In this regard, the search for methods and techniques that optimize the diagnosis of fat hepatosis is relevant. Modern methods of radiation diagnostics of liver density characteristics can significantly reduce subjectivity in the assessment of changes due to the use of quantitative indicators.

The aim of study - improving the quality of x-ray diagnostics of fat liver disease based on a precision assessment of the density of the liver parenchyma using computed tomography.

A comparative retrospective analysis of the results of a comprehensive clinical and radiological examination of 115 men of working age in the range of 40-55 years was performed. The main group (48 people) - employees of machine-building plants: shapers, stumpers, fitters-assemblers who had industrial contact with such factors as local vibration, dust, noise, muscle strain, burdened with a long alcoholic history and the presence of signs of metabolic syndrome: hyperlipidemia, impaired tolerance to carbohydrates, diabetes, abdominal obesity. The comparison group included representatives of auxiliary professions without clinical signs of pathology (47 people), comparable in age and experience with the main group. X-ray examinations were performed using computer tomographs: "HI Spead CT/e Dual" by GE Medical Systems and "Aqulion 64" by Toshiba. To measure the liver density in Hounsfield units (HU), the ROI (zone of interest) tool was used, which allows determining the desired value over areas of different dimensions. Measurements were performed on computer screens in 4 zones of interest at 4 levels of scanning of the liver lobes (apex, level of the caval gate, level of the left lobe, level of the portal gate) with the calculation of the average values of the density index (IDH) and density gradients (IDG) relative to the aorta, spleen and kidney.

Analysis of the results of a posteriori CT densitometry of various parts of the liver within the framework of the developed algorithm, including the use of absolute and relative (gradient) x-ray density indicators of hepatic, vascular (aorta),splenic and renal structures, allowed us to expand our understanding of the quantitative density characteristics both in normal and in patients with signs of diffuse fat hepatosis (FH). It was found that the liver parenchyma density indicators can be a kind of (conditional), sometimes the only indicators of the degree of severity of changes that objectively manifest positive or negative dynamics of pathophysiological processes and, in particular, at the initial stages of the development of the studied pathology. Density differences in the right and left liver parenchyma in the control group (conditional norm) in terms of absolute density and its gradient, regardless of the level of scanning, were insignificant (statistically unreliable). In patients with clinical signs of fatty liver infiltration at the stage of steatosis, in the absence of x-ray morphologically detectable structural changes, a decrease in IDH and the dynamics of its increase (recovery) at various stages of observation were revealed. Even with comparatively equal IDH of the evaluated departments, the IDG of different people differed, manifesting the individuality of metabolic processes occurring in the body, in particular in the liver, is a kind of indicator of their direction and severity. The significance of density indicators as predictors of the subsequent stages of the pathology under consideration was particularly evident in the analysis of the results of primary diagnostics and its development in the dynamics of observations.

The application of the developed methodological approach allowed us to expand our understanding of the possibilities of KT-liver densitometry in patients with metabolic syndrome (hyperlipidemia, impaired carbohydrate tolerance, diabetes mellitus, abdominal obesity) in the diagnosis of fatty liver disease (FLD) at various stages of examination, including in the early subclinical phases of pathology development. The results obtained indicate the predominant role of ethyl alcohol as a hepatotoxicant in the development of FLD in the estimated cohort of the working-age population. The use of an original algorithm for evaluating tissue density makes it possible to significantly ensure the objectivity of the interpretation of research results.

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