Instrumental Methods of Researching Kidney Function in the Conditions of Development of Chronic Disease and in the Long Term After Crash Syndrome

INTRODUCTION. Chronic kidney disease (CKD) is a global medical problem. In the arsenal of diagnostic methods for studying kidney function, in addition to laboratory methods, instrumental methods are used to diagnose early and late pathological changes in CKD and in the long term after a crash syndrome. Analysis of literature studies has shown that ultrasound diagnostics (US) can be used as part of the initial examination during a medical examination as a screening method. If a deviation from the reference values of ultrasound examination is detected, patients should undergo a more in-depth examination using multislice computed tomography (MSCT), magnetic resonance imaging (MRI), scintigraphy, or dynamic positron emission tomography (PET-CT). PURPOSE. The purpose of this work is to summarize literature studies devoted to the study of the possibility of using modern instrumental methods to determine kidney function in different stages of chronic kidney disease, in the early and late stages after the suffered crash syndrome and changes in the kidneys under the influence of other pathological factors. RESULTS. Analysis of literature studies showed that ultrasound diagnostics (US) can be used as part of the initial examination during a medical examination as a screening method. This is especially important given the prevalence of chronic renal failure and impaired renal function at different times after the transferred crash syndrome, the frequency of which in Ukraine is high in the military and civilian population due to military operations. If significant changes in the renal parenchyma are detected during ultrasound, a more in-depth study should be performed using Doppler mapping and calculation of the resistance index in the renal vessels. If ultrasound and Doppler mapping reveal significant changes in the renal parenchyma and renal vessels, patients should undergo a more in-depth examination using multispiral computed tomography (MSCT), magnetic resonance imaging (MRI), scintigraphy, or dynamic positron emission tomography (PET-CT). When examining functional and morphological changes in the kidneys in patients with different stages of chronic kidney disease, as well as in patients who have suffered a crash syndrome, the doctor should have not one, but several instrumental methods in his arsenal (i.e., rely on a hybrid study) that can most accurately help to correctly stage the disease and predict the prognosis. MSCT, together with the determination of serum creatinine (SCr) to calculate the glomerular filtration rate (eGFR), allows for the determination of individual kidney function. MSCT allows for the assessment not only of the anatomical structure of the kidneys, but also to create a 3D image, assess perfusion and non-invasively calculate the glomerular filtration rate. MRI allows for the assessment of a number of parameters (kidney volume, renal artery blood flow, renal cortex perfusion, etc.), as well as for MR histological examination of the kidneys, which allows for non-destructive assessment of the organ in a 3D image and may in the future allow for the assessment of not only the functional capacity of the kidney and its segments or an individual nephron. Dynamic PET imaging using filtered glomerular Ga-DOTA tracer has the potential for noninvasive assessment of GFR using kinetic compartment modeling, which allows not only to visualize renal function, but also to accurately measure it using an activity purification chamber. Dynamic nephroscintigraphy will allow to assess changes in blood flow in the renal vessels, secretion and excretion of the radiopharmaceutical, and static one will determine the structure of the kidneys with the detection of fibrotic and cicatricial processes in patients with CKD, and in the late stages after a crush syndrome of several millimeters in size. Today, nephroscintigraphy and PET imaging using selected radiopharmaceuticals remain the gold standard for determining function and morphological changes in the kidneys. CONCLUSIONS. Modern instrumental methods of assessing kidney function open up wide opportunities for their clinical application. Instrumental studies of changes in the kidneys under the influence of various pathological factors and at different times after the suffered crash syndrome should begin with ultrasound during a medical examination as a screening method. If significant changes in the renal parenchyma are detected during ultrasound, a more in-depth study should be performed using Doppler mapping, MSCT, MRI, scintigraphy or PET-CT. A comprehensive study of functional and morphological changes in the kidneys in patients with different stages of chronic renal failure, as well as in patients who have suffered a crash syndrome, should be carried out using several instrumental methods (hybrid study) that can most accurately help to correctly stage the disease, choose optimal treatment methods and make an adequate prognosis.