INTRODUCTION: Renal cell carcinoma (RCC) is a heterogeneous group of diseases. The most common type of RCC is clear cell RCC. Tumor biopsy is the «gold» standard for verifying the diagnosis, however, it can be unsatisfactory due to the characteristic heterogeneity of the RCC structure. Non-invasive diagnostic methods — computed tomography and magnetic resonance imaging — in combination with the use of texture analysis can potentially provide a large amount of information about the structure of the kidney tumor and the presumed degree of its differentiation (grade).
OBJECTIVE: Тo analyze publications devoted to texture analysis in RCC, the possibilities and prospects of using this method to increase the information content of CT and MR studies.
MATERIALS AND METHODS: Our review presents data obtained from available sources PubMed, Scopus and Web of Science, published up to March 2022 inclusive, found using the keywords: renal cell carcinoma, CT, MRI, texture analysis, radiomics in Russian and English.
RESULTS: The literature review describes the methods of texture analysis: selection of the region of interest, modality and contrast phase of the study, diagnostic aim. Based on the results of published scientific papers, the authors conclude that the use of texture analysis makes it possible to predict the grade of RCC with high sensitivity, specificity and accuracy, as well as to make a differential diagnosis of RCC with other kidney neoplasias, primarily lipid poor angiomyolipomas.
CONCLUSION: The use of texture analysis based on published materials is extremely promising for non-invasive prediction of RCC grade and its differential diagnosis, however, the difference in methods and the lack of standardization of texture analysis requires additional research.

INTRODUCTION: The literature review presents the possibilities of existing methods of radionuclide diagnosis of endogenous ACTH-dependent hypercorticism, which includes Itsenko-Cushing’s disease and ectopic ACTH syndrome. The similar clinical picture of these pathologies significantly complicates their differential diagnosis. Localization of corticotropinoma, especially in patients with persistent Cushing’s disease, and ectopic focus of ACTH hyperproduction also causes difficulties.
OBJECTIVE: To analyze the available foreign and domestic literature to determine the possibilities of radionuclide imaging methods in the diagnosis of endogenous ACTH-dependent hypercorticism.
MATERIALS AND METHODS: A search of scientifiс publications and clinical recommendations in the information and analytical systems PudMed and elibrary over the past twenty years, dedicated to the diagnosis of Itsenko-Cushing’s disease and ectopic ACTH syndrome using radioisotope diagnostic methods by keywords «Itsenko-Cushing’s disease», «ectopic ACTH syndrome», «radionuclide diagnostics», «scintigraphy», «SPECT», «PET».
RESULTS: The presented review demonstrated the broad possibilities and prospects of using modern radioisotope imaging methods in the diagnosis of endogenous ACTH-dependent hypercorticism. Radionuclide imaging methods make it possible to conduct a study in the «whole body» mode, which makes it possible to detect not only the primary tumor focus, but also metastases in patients with ectopic ACTH syndrome in one study. In addition, the use of scintigraphy or positron emission tomography with labeled somatostatin analogues makes it possible to predict the effectiveness of treatment of formations producing adrenocorticotropic hormone with somatostatin analogues, which is important when planning antitumor therapy.
CONCLUSION: The use of radioisotope diagnostic methods significantly increases the accuracy of topical diagnosis of a tumor focus, allows for an assessment of the prevalence of the tumor process and the selection of patients for antitumor therapy using somatostatin analogues.

INTRODUCTION: Currently, the most common variant of the reproductive system disorders, in particular menstrual cycle disorders, in adolescent girls is oligomenorrhea. In situations after a complete diagnostic screening no organic and endocrine pathology of the reproductive system is detected in this group of patients, it is possible to conduct functional MRI as a method of identifying cause-and-effect relationships and clarifying the pathogenesis of menstrual disorders.
OBJECTIVE: To analyze the available foreign and domestic literature to determine the role of magnetic resonance imaging in the diagnosis of functional brain changes in menstrual disorders in adolescent girls.
MATERIALS AND METHODS: A search was conducted for scientific publications in the information and analytical systems PubMed and Google Scholar for 2013–2023 by keywords: «resting-state functional MRI» («functional resting MRI»), «oligomenorrhhea» («oligomenorrhea»), «adolescent girls» («teenage girls»), «reproductive system functional disorders» («functional disorders of the reproductive system»), «magnetic resonance imaging» («magnetic resonance imaging»), «diagnostic radiology» («radiation diagnostics»). 46 publications related to the diagnosis of functional brain changes in menstrual disorders in the form of resting state fMRI were analyzed.
RESULTS: Resting state fMRI allows us to assess the basic brain activity in the absence of certain sensory or cognitive stimuli and visualize working networks that include various parts of the brain demonstrating synchronous changes in the BOLD-signal at rest. There are a number of patterns of changes in the BOLD-signal that can be observed in various phases of the menstrual cycle, as well as under the influence of stress factors, which makes it possible to visualize the morphological substrate of oligomenorrhea that occurs against the background of the absence of organic and endocrine pathology of the reproductive system in adolescent girls. Currently, there is little data in the scientific literature on the use of functional resting MRI in this cohort of patients, however, this method can have a significant impact on the formation of an individual plan for the correction of reproductive disorders in adolescence, and therefore requires further study.
CONCLUSION: The use of fMRI can open up new possibilities in the diagnosis of functional brain disorders in girls with «unexplained» oligomenorrhea.

INTRODUCTION: Major depressive disorder is a common mental health disorder. Alterations in cortical structures have been identified in this disease, but findings have been variable and inconsistent. Previous studies have illustrated that the cingulate and prefrontal gyrus, along with the amygdala, are involved in emotional processing and the development of abnormal emotional responses in depression.
OBJECTIVE: Our research aims to investigate the neurological structural differences and alterations in ACC, bilateral amygdala, and dmPFC regions in patients with MDD using quantitative MRI (MPF and Diffusion parameters mapping (DPM), including diffusion kurtosis).
MATERIALS AND METHODS: In this study, we utilized advanced quantitative MRI techniques, specifically Diffusion Tensor Imaging, Diffusion Kurtosis Imaging, and Мacromolecular Proton Fraction Mapping, to investigate microstructural differences and alterations in the specific regions in patients diagnosed with major depressive disorder. RESULTS: Our findings revealed no significant interaction between Мacromolecular proton fraction Mapping with depressive disorder. However, patients with major depressive disorder exhibited a statistically significant increase in apparent mean, axial and radial diffusivity (F=6.3, p=0.01, F=5.0, p=0.03, F=7.08, p=0.01, respectively) in the bilateral amygdala compared to healthy controls, as well as in mean and radial diffusivity in the anterior cingulate cortex (F=5.61, p=0.02, F=7.08, p=0.01, respectively).
DISCUSSION: These findings suggest that altered molecular diffusion characteristics in the amygdala and the anterior cingulate cortex may be specifically associated with major depressive disorder.
CONCLUSIONS: The importance of using new quantitative MRI methods to assess structural changes at the molecular level in the brain is shown, which, ultimately, expands the fundamental understanding of the pathophysiology of depression.

INTRODUCTION: Modern and effective diagnosis of osteomyelitis is the basis for successful therapy; at the same time the problem of establishing this pathology, especially in the early stages of the development of the process, has not been completely resolved.
OBJECTIVE: To develop of ultrasound imaging of metaepiphyseal osteomyelitis in young children, depending on the duration of the disease.
MATERIAL AND METHODS: 108 children (boys — 65% (70/108), girls — 35 (38/108)) from 1 month to 2 years were examined. Children's age from 2 up to 8 months — 57% (62/108), newborns — 26% (27/108). The age of other children: 12% (13/108) — 9–12 months, 5% (6/108) — 1– 2 years. All children underwent x-ray and ultrasound study. The diagnosis of osteomyelitis was verified by joint puncture (n=102), bone puncture (n=57), drainage of periarticular phlegmon (n=12).
Statistics: processing of the study results was carried out using the Statistica 13.0 application package (TIBCO Software Inc, 2017). To assess the effectiveness of ultrasound in the diagnosis of acute osteomyelitis, the diagnostic effectiveness and predictive value of positive or negative results were calculated, and the likelihood ratio was calculated.
RESULTS: 3 groups were identified depending on the duration of the disease at the time of admission to the hospital: Ia — 1–3 days, Ib — 4–7 days, Group II — 8–14 days, Group III — 15–21 days from the onset of the disease. DE indicators for patients of group Ia: sensitivity — 81.8%, specificity — 60.0%, accuracy — 75%, PV(+)=81.82%; PV(–)=60.00%; OR=4.50. DE indicators for patients in group Ib: sensitivity — 86.6%, specificity — 66.6%, accuracy — 80.95%, PV(+)=87.5%; PV(–)=60.0%; OR=7.00. DE indicators for patients in group II: sensitivity — 92.98%, specificity — 80.0%, accuracy — 93.44%, PV(+)=98.15%; PV(–)=57.14%; OR=37.86. DE indicators for patients of group III: sensitivity — 91.66%, specificity — 91.0%, accuracy — 91.66%, PV(+)=100.0%.
DISCUSSION: Ultrasound imaging of acute osteomyelitis in children of group Ia included nonspecific changes in periarticular tissues and had the lowest diagnostic accuracy (75%). Diagnostic accuracy increased in group Ib to 85% due to initial structural changes in the zone of preliminary calcification and hyaline cartilage of the epiphysis. Disease progression in group II was characterized by more distinct structural changes in the metaphysis with an increase in diagnostic accuracy to 93%. In patients of group III, the highest rates of diagnostic accuracy (91.67%) were obtained due to visualization of destructive changes in the epiphysis, metaphysis and zone of preliminary calcification.
CONCLUSION: The ability to detect ultrasound signs of acute hematogenous metaepiphyseal osteomyelitis in children will allow the use of this method in the early diagnosis for the timely selection of an adequate treatment tactics.

INTRODUCTION: Spinal cord injury (SCI) in young children includes a relatively higher prevalence of cervical spine injury, multiple thoracic vertebral compression fractures, and spinal cord injury. Spinal cord injuries without radiological changes/signs of fractures or dislocations (SCIWORA) also occur in young children. X-ray assessment of damage to immature vertebrae and cartilage in young children is difficult, since incompletely formed vertebral bodies can be confused with fractures. Accordingly, an MRI is required, which provides a detailed anatomical image of all structures of the spinal column and also diagnoses damage to the spinal cord, ligaments and muscles.
OBJECTIVE: To investigate the possibilities of methods of radiation diagnosis of spinal cord injury in young children (up to 3 years).
MATERIAL AND METHODS: 20 children aged from 11 months up to 3 years old were studied with spinal cord injury. X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The standard MRI protocol for SCI in children under 3 years of age included: MR myelography in the coronary and sagittal projections, sagittal projection STIR, DTI and T2WI FS SE, axial projection T2WI FS SE or T2*WI FS GE; coronary projection T2WI SE; 3D T1WI FS GE before and after contrast enhancement.
RESULTS: An analysis of the data of patients included in the category of polytrauma was carried out. The causes of SCI in these patients were road accidents and falls from various heights. X-ray and CT scans were uninformative, and had large discrepancies with MRI results. All anatomical and morphological changes revealed by MRI correlated well with clinical manifestations and corresponded to the classification of the level and severity of spinal cord injury (ASIA). An increase in the volume and change in the signal of the spinal cord due to edema and / or hemorrhage in the spinal cord is the main sign of damage to the spinal cord, and is best indicated on T2WI and STIR, as a hyperintense signal.
DISCUSSION: MRI is critical in the emergency assessment of spinal cord injury or compression to predict the outcome of SCI. There is currently no spinal cord imaging technique that can compete with MRI. Increased volume and signal changes in the spinal cord due to edema and/or hemorrhage are a sign of spinal cord injury and are best demonstrated on T2WI and STIR as a hyperintense signal. Incomplete spinal cord injury is also manifested by a hyperintense signal on T2WI and/or FLAIR, which in intensity and extent correlates with the degree of injury. Hemorrhagic injuries are better detected using T2*GRE or SWI, and spinal cord edema is better detected using T2WI SE and STIR. In addition, STIR can identify bone marrow edema in injured vertebrae, even when the injury is not detected on CT.
CONCLUSION: When performing MRI in patients with SCI, three quantitative parameters should be assessed: the maximum damage to the spinal cord, the maximum compression of the spinal cord, and the length of the affected area. In addition to the results of quantitative parameters, potential predictive qualitative MRI findings should be evaluated such as intramedullary hemorrhage, focal and diffuse spinal cord edema, soft tissue injury, probable stenosis before injury, and disc herniation.

INTRODUCTION: Localization of abnormal parathyroid glands in persistent or relapsed patients with primary hyperparathyroidism presents problems for surgeons before repeated surgery. There is no clear standard for the choice of diagnostic modality for localization of PG in this group of patients.
OBJECTIVE: To search for the optimal diagnostic protocol of the parathyroid pathology preoperative diagnosis in patients with primary hyperparathyroidism with persistent or recurrent disease.
MATERIALS AND METHODS: 55 patients diagnosed with persistence or recurrence of PHPT who underwent repeated surgical treatment were included in the study. Before surgical intervention all patients underwent laboratory and instrumental investigations in the volume of: blood tests for PTH, TTH, ionized calcium, 25(OH)D, creatinine, phosphorus, neck ultrasound, parathyroid scintigraphy by washout method, dual-isotope subtractive scintigraphy of parathyroid glands (early and delayed phases), SPECT of parathyroid glands (with uptake correction), computed tomography of the neck with intravenous bolus contrast.
RESULTS: CT and planar subtraction dual-isotope scintigraphy showed the highest DA in the overall group (persistence and recurrence) (78% and 78%), with the DA of these methods differing slightly (88% and 92%) and overall accuracy being higher for CT (90% and 87%). Neck ultrasound showed the lowest rates among all methods (DA — 46%, DS — 80%, OA — 67%). Planar scintigraphy (washout) and SPECT were comparable in their informativeness: DA — 67% and 65%, DS — 96% and 98%, OA — 85% and 86%.
DISCUSSION: The most commonly used current diagnostic search algorithm before reoperation is visualization of the thyroid gland by two modalities: Neck ultrasound and parathyroid scintigraphy (washout/subtraction) or SPECT-CT. In doubtful cases, the second step is computed tomography of the neck with contrast or PET/CT. It is extremely difficult to choose one optimal diagnostic method, as none of them has 100% diagnostic accuracy. In addition, each study has limitations, and the availability of some modalities is limited. In our study, the location of pathologically altered thyroid was correctly recognized in 90% of cases by CT with contrast and in 87% of cases by planar subtraction dual-isotope scintigraphy. The informativeness of neck ultrasound showed the lowest values of all modalities. SPECT and planar washout scintigraphy took an intermediate position in terms of diagnostic accuracy.
CONCLUSION: Isolated ultrasonography of the neck has low diagnostic accuracy in patients with primary hyperparathyroidism with persistent or recurrent disease. We recommend the combination of US with contrast-enhanced computed tomography of the neck or US with dual isotope subtraction scintigraphy of the parathyroid glands, which have the same diagnostic accuracy. SPECT and planar washout scintigraphy can be used for the diagnosis of abnormal parathyroid glands in persistent or recurrent patients with primary hyperparathyroidism when more informative techniques are unavailable. When the techniques were combined, the combination of ultrasound/CT with contrast and ultrasound/planar subtraction dual isotope scintigraphy showed the best results with DA of 85% and 86%.

INTRODUCTION: After the COVID-19 pandemic, there is increasing evidence that many patients show fibrous changes in lung tissue accompanied by functional lung disorders. Objective data on the histopathogenesis of such changes is still insufficient. Prospective studies are required to fully assess the consequences of these clinical manifestations.
OBJECTIVE: Evaluation of the capabilities of digital processing of histological preparations of lung tissue and their comparison with quantitative CT data of lung patients in the acute phase of COVID-19.
MATERIALS AND METHODS: The study included data from patients after COVID-19 (7 women and 3 men aged 47 to 93 years) who died after the acute phase of COVID-19 from extrapulmonary causes. The control group included data from 7 people (5 women and 2 men aged 35 to 93 years) who died shortly after hospitalization from extrapulmonary causes (myocardial infarction or acute cerebral stroke), with no signs of lung diseases, including autopsy results. Digital processing of histological preparations of lung tissue obtained during autopsy was carried out, and their comparison with the results of quantitative semi-automatic processing of CT data.
Statistics. Beta regression (mgcv library) was used. The model was characterized by a pseudodetermination coefficient R². The association was considered statistically significant at p<0.05.
RESULTS: A reliable dependence of the severity of fibrous changes in histological samples on the results of quantitative analysis of CT images of patients in the acute period of COVID-19 was demonstrated.
DISCUSSION: Extrapolation of lung autopsy data through quantitative CT assessment is one of the ways to pre-diagnose and identify groups of patients who require specific treatment of post-COVID-19 pulmonary fibrosis.
CONCLUSION. Computerized digital processing of histological images made it possible to correctly compare the histopathological examination data with the CT picture in COVID-19, which could potentially have a prognostic value in the search for more effective treatment strategies.

INTRODUCTION: Despite the fact that acute hematogenous osteomyelitis is classified as a sufficiently studied disease, the percentage of diagnostic errors is still quite high. Timely diagnosis is crucial for the successful outcome of the disease, therefore, visualization should be aimed at early diagnosis and, as a result, successful treatment of the disease.
OBJECTIVE: To identify early patterns in the intramedullary phase of the course of acute hematogenous osteomyelitis (CSO) with a multimodal approach of radiation research methods.
MATERIALS AND METHODS: Twenty patients underwent a comprehensive examination, including multispiral computed tomography (MSCT) using color mapping techniques.
RESULTS: In the intramedullary phase of the course of CSF, no pathological changes were detected during X-ray examination of the affected limb. Ultrasound in 75% of observations revealed a thickening of the periosteum of more than 1 millimeter (mm) in the affected bone. When using MRI in 93% of cases, and with MSCT in 95% of patients, signs of bone marrow edema were detected.
DISCUSSION: The role of computed tomography in the diagnosis of acute hematogenous osteomyelitis in children has received significant recognition in pediatric surgical practice in recent years, and the use of MSCT in the diagnosis of CSO has found application in domestic healthcare. At the same time, a fairly large number of researchers reported on the high informativeness of MSCT in the diagnosis of CSOs.
CONCLUSION: MSCT using the color mapping technique has a higher specificity compared to MRI and can be used as an integral method of the first level in the diagnosis of the intramedullary phase of the CSF course.

INTRODUCTION: Flat deformities are one of the most common pathological changes of the feet. Flatfeet is a disease with high social significance, since it not only affects on the quality of life, but is also an important factor in classification of fitness for military service. The main method of diagnosis of these diseases is radiography of the feet in a lateral projection in the standing position. Despite numerous publications describing various methods for assessing the ratio of the bones of the foot, there is no consensus in the scientific community about the exact criteria for flatfoot and its degrees. At the same time, it is noted that the final conclusion is influenced not only by the method of evaluating the finished image, but also by the method of conducting the study. The construction of modern digital X-ray systems in most cases is not adapted for classical X-ray podography, and the study without special devices and the impossibility of strict adherence to the methodology lead to significant distortions of the results. It follows from this that specialized equipment is required for the diagnosis of flatfoot deformities, which allows developing a unified methodology for conducting research and limiting the possibilities of simulations and aggravations.
OBJECTIVE: To determine the possibilities of cone-beam computed tomography in the diagnosis of flatfoot deformities in a standing position with a natural load.
MATERIALS AND METHODS: This study included 100 patients underwent examination at the S.M.Kirov Military Medical Academy. All patients were examined using the classical radiography and using the cone-beam computed tomograph (CBCT) «ATRISS» (Electron, Russia). Tomograms were evaluated by two methods: using an averaged image and using a thin slice. The study was conducted by two doctors with the determination of the height and angle of the arch of the foot, followed by an assessment of the degree of flatfoot.
Statistics. Statistical analysis was performed using Medcalc software (version 18.2.1). The absolute results of measurements for longitudinal and transverse flatfoot obtained by various methods were compared, as well as the time spent on the study (Wilcoxon and Friedman criteria), the degree of correlation between measurements (Spearman’s criterion), as well as the degree of consistency of the conclusions of two experts to identify longitudinal and transverse flat feet (Kappa-Cohen coefficient). RESULTS: Angle measurements in absolute values did not differ significantly between all the methods used (p=0.1803). There were significant differences between measurements of the height of the arch of the foot between the X-ray method and CBCT (p<0.01). In a comparative analysis of radiography and CBCT, two experts noted a high consistency of research results. CBCT made it possible to perform studies with less time (p<0.01). The effective dose for CBCT is significantly higher than for radiography (p<0.01), but does not exceed 0.12 mSv.
DISCUSSION: According to the results of the study, it was found that the effectiveness of CBCT in the diagnosis of flatfoot deformities is not worse than classical radiography. At the same time, the CBCT allows you to avoid positioning errors, stacking and cases of attempted simulation. The effective dose for CBCT allows using the technique as a preventive study. Also, CBCT has a high throughput and allows you to get significantly more information in one scan than with radiography.
CONCLUSION: CBCT in a standing position with a natural load is not worse then classical radiography techniques in the accuracy of diagnosis of flatfoot deformities. At the same time, the CBCT has extensive postprocessing capabilities, higher throughput, low radiation load, and also reduces the likelihood of methodological errors and cases of aggravation. CBCT is promising in the consciousness of a universal methodology for measuring and classifying of flatfoot with a more precise formulation of setting points for measuring the angles of the arch and deviation of the hallux.

Endolymphatic sac tumors are rare neoplasms originating from the endolymphatic epithelium of the intraosseous part of the endolymphatic duct and sac, typically characterized by slow growth and local destructive changes. We present a case of an endolymphatic sac tumor in a 28-year-old man who consulted an otoneurologist with complaints of progressive hearing loss and dizziness attacks and was referred for a CT scan of the temporal bones and MRI of the inner ear with delayed contrast enhancement. The data of otoneurological and radiological examinations before and after surgical treatment and the results of surgical treatment with histological verification of the tumor are presented. The objective of this case presentation is to demonstrate the usefulness of CT and MRI methods in detecting an endolymphatic sac tumor, to compare the results of otoneurological and radiological examinations and intraoperative and histological data followed by surgery. Radiological examination revealed a neoplasm of the right temporal bone with typical imaging characteristics of endolymphatic sac tumor. Surgery was performed, the mass was removed completely, and the endolymphatic sac tumor was histologically verified. Radiologic presentation includes a typically located area of bone destruction in the petrous part of the temporal bone in the area of the vestibular aqueduct, possibly with the spread of the tumor into the cerebellopontine angle, with a heterogeneous structure, with uneven contrast enhancement. Due to the rarity of this pathology, diagnosis in the early stages is often difficult, and for the correct interpretation of radiologic findings in patients with hearing loss and dizziness, knowledge of the normal anatomy of the temporal bone and awareness of rare variants of its lesions are of key importance. Timely examination of patients with suspected temporal bone lesions and correct diagnosis are the key to successful treatment and maintaining the quality of life in this group of patients.