Methods of computer simulation in the development of technology for the functional assessment of the state of the liver in patients

Abstract

Most of the diseases associated with carbohydrate and fat metabolism disorders (type 2 diabetes mellitus, obesity, metabolic syndrome) lead to changes in the structure and function of liver cells, and the formed liver dysfunction negatively affects the further progression of the disease. The process of liver damage develops with varying intensity and does not immediately lead to irreversible consequences; therefore, dysfunction should be detected as early as possible, and the data obtained should be used to assess the current state and predict their reversibility.Study purpose. To create a quantitative assessment method that allows to assess the current functional state of the liver and to determine the reversibility of existing functional disorders and the severity of structural changes, to assess the prognosis of the course of the disease and the effectiveness of restorative measures.Instruments and Data Collection Procedure. Examination of patients, in addition to conventional methods, included an assessment of the absorptive-excretory function of the liver and biliary tract patency using a scintillation gamma camera (Siemens Symbia T16) with subsequent processing on the SUPER-SEGAMS computer system (Hungary). Freshly prepared Bromesida, 99mТс was administered intravenously at the rate of 1.1 MBq per kg of the patient's body weight, with a normal content of bilirubin in blood. Series of scintigrams allow to assess the passage of the drug visually through the blood-liver-ducts-intestine system, to characterize the anatomical features and organic changes in the biliary system. Quantitative analysis of the "activity-time" curves obtained from the areas of interest (the right lobe of the liver - 2 zones, the left lobe of the liver, the common bile duct, the intestinal area, the heart area) makes it possible to study the absorptive-excretory function of the liver.Results. By the method of mathematical modeling, a formula was obtained - the index of the functional activity of hepatocytes:IFAH= (-1,1564 + 0,0653 × BMI - 0,0144 × Tmax) × 100,where:IFAH - index of functional activity of hepatocytes (liver cells);BMI - body mass index (kg/m2)Tmax - indicator of the absorption function of the liver (min) - the time to reach the maximum accumulation of the radiopharmaceutical in the liver. It is an indicator of the function of polygonal liver cells (normal = 8-12 min).Functional activity of hepatocytes: from 0 to 9.9 - normal functional activity of hepatocytes; from 10 to 19.9 - the risk of developing functional disorders; from 20 to 29.9 - reversible dysfunction of hepatocytes (steatosis); more than 30 - irreversible (organic) liver dysfunction (steatohepatitis). With negative IFAH values - the influence of extrahepatic factors, such as diseases that accelerate metabolism at the cellular level (thyrotoxicosis), taking drugs in violation of the prescriptions before these studies.The originality and novelty of the technique are confirmed by the patent – “A method for diagnosing fatty hepatosis” (patent RU 2 578 080 C2 dated February 19, 2016).The method was tested in clinical practice and the data obtained confirmed the high diagnostic accuracy (95%) of the proposed method for calculating the index of IFAH.Conclusion: the discussed method allows doctors to evaluate not only the current functional state of the liver, but also to determine the reversibility of existing functional disorders and the severity of structural changes; also could be used to evaluate the prognosis of the course of the disease and the effectiveness of restorative measures. It is characterized by relative ease of implementation. Only one parameter — Tmax is required, after which the study can be completed.