Introduction. One of the important problems of medical imaging is the differential diagnosis of patients with acute and chronic pulmonary embolism. The widely used minimally invasive technique of multispiral computed tomography with intravenous bolus contrast enhancement can serve to solve this problem, in particular, to assess the state of the parenchyma and vascular structures of the lungs.

The purpose. To assess the state of bronchial arteries and parenchymal changes in the lungs in pulmonary thromboembolism based on the results of multispiral computed tomography and their role in the more precise diagnosis of this disease.
Materials and methods. An analysis of CT-angiopulmonography of 600 patients with suspected PE was performed. 87 patients with confirmed pulmonary thromboembolism were selected and divided into groups according to the final diagnosis: group 1 — acute pulmonary embolism, group 2 — chronic pulmonary embolism. CT data were analyzed for the presence of pathologically changed bronchial arteries, as well as lung's parenchymal changes (including mosaic perfusion, fibrotic changes, bronchial dilatation with or without wall thickening).
Results. Bronchial arteries were assessed in patients with acute and chronic pulmonary embolism and the diagnostic value of the detected changes was determined. Acute pulmonary embolism does not lead to such dilatation of the bronchial arteries as chronic pulmonary embolism. In diagnostically unclear cases, secondary parenchymal signs visible on CT (mosaic perfusion and dilated bronchi without wall thickening) can be useful in the differential diagnosis of acute and chronic pulmonary embolism.

Conclusions. Most patients with chronic pulmonary embolism demonstrated dilated bronchial arteries, in contrast to patients with acute pulmonary embolism. Lung's parenchymal changes (a mosaic perfusion pattern and bronchial dilation without wall thickening) were more common in patients with chronic pulmonary embolism. These CT-signs can help differentiate acute from chronic pulmonary embolism in unclear clinical situations.

Introduction. MR-morphometry is a method of image processing independent of the researcher, which allows you to get the results of measuring the volume of the brain structures and the thickness of various areas of the cortex and helps in the differential diagnosis in assessing the results of MRI. Our study used MR-morphometry to identify structural markers in the differential diagnosis of vascular parkinsonism in the examination of patients with Parkinson's symptoms. Purpose of research. Visualization of the distribution of atrophic changes in brain structures in vascular parkinsonism and in the advanced stages of Parkinson's disease, as well as the identification of characteristic parts of the brain that undergo a pathological process to increase the accuracy of differential diagnosis. Materials and methods. The results of magnetic resonance morphometry of patients using the postprocessing of native MR images using Freesurfer software are analyzed. We examined 29 patients with vascular parkinsonism and 19 patients with Parknison disease, at stage 4 according to Hyun and Yar. Summary. The application of the method of postprocessing data processing of MR-morphometry allows instrumental confirmation of the clinical diagnosis, as well as to clarify the pathogenesis of neurological syndromes observed in progressive supranuclear paralysis.

Introduction. We examined the experience of performing perfusion studies of the brain, and analyzed the errors in the procedure and interpretation of studies. The data obtained made possible to understand better the reasons that led to errors and how to avoid them in future practice. Purpose: to reduce the number of perfusion studies of the brain, which interpretation is not possible or might be performed with errors. Objectives: to analyze the reasons that led to the inability to analyze the perfusion or difficulties in interpretation of the data obtained, to divide them into groups of factors that influenced the study. To develop an algorithm to reduce the number of «unsuccessful» studies. Materials and methods: retrospectively evaluated 275 CT and MRI studies of brain perfusion performed between 2017 and 2019. Results: the result of this study was a reduction of the number of uninformative studies and errors in the interpretation of correctly obtained data. Conclusion: monitoring the MRI and CT perfusion studies allows to avoid uninformative studies. The standardization of the examination method allows to evaluate the dynamics of changes, regardless of modality.

Introduction. The minimum size of malignant brain tumors detected by positron emission and computed tomography (PET-CT) exceeds 6-7 mm. One of the ways to increase the sensitivity of PET-CT in detecting of malignant brain tumors is to increase the administered activity of the radiopharmaceutical 11C-choline.
Purpose & tasks. The aim of the study was to experimentally study the possibility of obtaining a small-size glioblastoma (GB) images (up to 4 mm) by PET-CT with the 11C-choline.
Materials and methods. The study was performed on 24 rats with implanted intracerebral tumor «Glioma C6» (glioblastoma). Animals underwent magnetic resonance imaging (MRI) with contrast enhancement (CE) and PET-CT with 11C-choline for 21 days after tumor transplantation.
Results. It was shown that using two methods: MRI with CE and PET-CT with 11C-choline, a glioblastoma up to 4 mm can be convincingly visualized.
Conclusion. The data obtained can be crucial for early detection of glioblastoma, justification of treatment tactics, evaluation of the treatment effectiveness and prediction the outcome of the disease.

The aim of this study: to assess the ability of different software products to automated volumetric quantification of lung emphysema and see whether the results can be interconvertible.
Materials and methods. This study is based on the results of recognition and analysis of computer tomograms using three different software products.
Results: all the programs we used have high sensitivity and specificity in recognition of lung emphysema. However, there are a number of errors that prevent accurate image analysis.
Conclusions. The interconvertibility of the results of the automated volumetric quantification of lung emphysema at this stage is not reliably determined and depends on the choice of software products used for analysis.

Introduction. Phenotype variants of left ventricular (LV) remodeling in patients with hypertrophic cardiomyopathy (HCM) are often associated with abnormalities of the mitral valve (MV), myocardiumstructure, contributing to the development of medium and/or subaortic obstruction. Itcauses the detail visualization of morphological obstruction substrates, tissue characteristics.

Aim. To evaluate the possibilities of magnetic resonance imaging (MRI) in the diagnosis of various forms of HCM and combined abnormalities.
Materials and methods. 75 patients with suspected HCM were examined. For verification, all patients underwentMRI using protocol: short-pulse T1w-TSE/ T2w-TSE (STIR), gradient echo in cine (CINE), T1-weighted post-contrast images (Inversion Recovery IR-MDE). Results. Patients classified into 4 types according to the anatomical principle (Wiggle E.D. et al., 1985). In addition to the most frequent forms affecting the interventricular septum (IVS) — 64 patients, unusual forms covering the apical zones and papillary muscles — 11 patients. The majority of patients were diagnosed with abnormalities of MV, divided into abnormalities of the number and position of papillary muscles, as well as the ratio of chords and muscles. Myocardial crypts were diagnosed in 12 patients, some combined with areas of non-compact myocardium. Post-contrast visualization using the delayed contrast technique allowed differentiating HCM with accumulation diseases, excluding cavity thrombosis, and evaluating the severity of myocardial fibrosis.
Conclusions. MRI allows to estimate in details anatomic picture of LV remodeling, to diagnose features of the mitral valve, tissue characteristics that allows to stratify risk of sudden death, classify the HCM phenotype form and to determine the volume of surgical intervention.

Introduction. In 2016, updated recommendations for echocardiographic diagnosis of diastolic dysfunction were developed. It requires a review of the degree of metabolic syndrome (MS) influence on the heart and blood vessels remodeling and the development of left ventricle (LV) diastolic dysfunction (DD).
Purpose. Assessment of the MScontribution to the heart and blood vessels remodeling, as well as to the development of LVDD with an analysis of the LV remodeling types and the degree of LVDD.
Materials and methods. The main group: 130 patients with MS (62 (47,7%) — men, 68 (52,3%) — women; average age — 59,8±9,5 years) who underwent in-patient examination and treatment in the cardiology department for arterial hypertension (AH) in 2015-2017. The control group included 36 patients with AH (18 (50%) — men, 18 (50%) — women; average age — 56,0±12,7 years) without abdominal obesity, not meeting the criteria of MS International Diabetes Federation.
Results. MS is associated with increased prevalence of adverse LV remodeling and DD. In MS group concentric LV hypertrophy was detected significantly commoner than in group without MS, in which concentric remodeling was the most frequent structural abnormality. Eccentric LV hypertrophy was diagnosed only in pts with so-called complete MS. Moreover DD was detected in all pts with complete MS. Type 2 DD was present predominantly in subgroup with complete MS, reflecting relationship between the degree of LV DD and severity of MS in AH pts.
Conclusions. Obtained results confirm adverse influence of central obesity and MS on LV myocardial structure and function.

Introduction. Became possible to evaluate association between the elasticity of aorta and coronary atherosclerosis using echocardiography.
Purpose. To evaluate the association between worsening of the local thoracic aorta elasticity and the severity of coronary atherosclerosis.

Material and methods. With the application of echocardiography and coronarography there were examined 109 patients.

Results. With stenosis >70%, occlusion or lesion of 2 or more coronary arteries, statistically significant differences were revealed.

Conclusion. Worsening of thoracic aorta local elasticity in patients with coronary atherosclerosisis associated with the severity of coronary atherosclerosis.

Introduction. Mismatching of the organ sizes to the standard measurements is the sign of pathology, so it is important to make measurements using the same method for the same type of assessment.
Goal: to evaluate the intra- and inter-research reproducibility of the oblique craniocaudal diameter measurement of the right liver lobe with the application of Russian and European methods by different operators, and find out which of the methods is the most convenient for practical application.
Materials and methods. 47 healthy volunteers and 3 operators were participated in the study. One of the operators participated in both stages of study.
Results. Keeping conditions such as quiet breathing and longitudinal scanning in the anterior axillary line from the VII-X intercostal spaces increases reproducibility and provides well visualization of the lobe even if the patient is not prepared for the study.

Conclusion. The oblique size of the right lobe is highly reproducible for both methods, but the European method (longitudinal scanning of right lobe) is more convenient for the practical application.

Purpose. To compare the capabilities of CT perfusion and MR elastography in predicting the risk of developing pancreatic fistula in patients with periampular tumors at the planning stage of pancreatoduodenectomy.
Materials and methods. CT perfusion and MR elastography were performed in 30 patients with no pancreatic diseases and 53 patients with periampular tumors, who were subsequently operated on in the volume of pancreatoduodenectomy.
Results. In patients with periampular tumors in 18 (44%) cases, the perfusion and stiffness indices in the pancreatic parenchyma did not differ from the control group, 35 (85,3%) showed a decrease in the main perfusion parameters, while a moderate increase in stiffness was noted in 23 (65,7%), expressed in 12 (34,3%). Against the background of preventive measures, only 3 (5,6%) patients, in all cases with a «soft» pancreas in the postoperative period, developed a pancreatic fistula.
Conclusion. CT perfusion and MR elastography are highly informative methods of quantitative and qualitative assessment of the pancreatic parenchyma, detection of fibrotic changes, and are effective in predicting the risk of developing pancreatic fistula.

Introduction. In the early hours and days after traumatic or surgical event it is essential to determine type of peripheral nerve injury accurately.
Objective. To assess performance of diagnostic ultrasound (US) in patients with traumatic and intraoperative nerve injuries during the early hours and days after trauma or surgery.
Materials and methods. 106 patients with clinical signs of extremity nerve injuries were included into the study. A total of 113 limb nerves were investigated with US.
Results. US sensitivity in the detection of complete nerve rupture was 100% (95% CI: 39,8-100%), specificity — 99,0% (94,7100,0%); for nerve compression with the bone sensitivity was 100% (66,4-100%), specificity — 100% (96,3-100%); for nerve compression with fixation devices sensitivity was 100% (66,4-100%), specificity — 100% (15,8-100%) и 100% (88,4-100%).

Conclusion. Nerve US is a reliable method for the evaluation of extremity nerve injury, the method can be recommended for use in the early hours and days after trauma or surgery.

The article presents statistical data on the state of Saint-Petersburg radiology as of 2019.