Puropose of the study. Basing on the previously obtained results on the proven high efficiency of magnetic resonance imaging (MRI) of the chest organs in the visualization of major lung diseases, in the current period of mass incidence of viral pneumonia (VP) caused by COVID-19, we tried to study the possibility of using MRI OGK to image lung damage in this pathology both in primary detection and for follow-up reconvalescence control.

Material and methods. MRI of the chest in T1 -, T2-weighted modes (T1-w, T2-w), also with fat suppression, diffusion-weighted, STIR-modes, in the axial and frontal planes, with breath holding, or with automatic synchronization of acquisition with breathing was carried-out in 47 patients with VP of various severity, 32 of them were confirmed by PCR as COVID-19, all did have a clinic of pneumonia. The control group comprised 15 volunteers, of them 8 non-smokers, and 7 smokers. In 18 patients, an CT study of the chest was also performed, with a step of 0.5–1.25 mm, with full coverage of the chest and reconstruction of axial and frontal slices, with a comparison of MRI and CT of the chest. In 8 patients, MRI of the chest was then performed again, for follow-up control of clinical recovery. There were no deaths among our patients

Results. The duration of a complete MRI examination of the chest was less than 25 minutes in all cases (21 ± 4 minutes on average), and less than 10 minutes in the chest CT. In all cases, MRI imaging of the affected area was achieved using a group of MRI protocols, which included axial T1-w and axial and frontal T2-w, and lasted < 12 minutes, counting the time for laying the patient.

In normal patients without pathology of the lungs, not smoking, the lung was visualized as a diffuse homogeneous air region with a minimum share interstitial and vascular space. In patients - smokers, lung MRI was slightly enhanced in the dorsal parts of both lungs, disorders of airiness and interstitial exudative changes weren't present. In the acute phase of the disease, pulmonary ventilation disorders and interstitial exudative changes that form the morphological basis of lung damage in COVID-19 were visualized as local, corresponding to the location and nature (sub-segmental, segmental, polysegmental) of the pathological focus, both T1-w and T2-w modes. MRI of the chest provided diagnosis of lung pathology in all cases, while the extent of the pathological focus on the MRI image in T2-w was 14–19% greater than on the CT. The correlation of the calculated volume of affected lung tissue between CT and MRI of the chest wasas high as r = 0.95 (p < 0.001). The values of the volume of the affected tissue in T1-w and T2-w did not differ from each other in the intergroup comparison and correlated strongly and reliably, r = 0.985 (p < 0.001). MRI in DWI mode showed a sensitivity of 81% (38/47) in detecting COVID-lung lesions. The duration of DWI in all cases was more than 6 minutes, more than twice as long as all other MRI protocols together. The volume of pleural effusion, clearly visible with T2-VI, in all our cases did not exceed 100 ml. In a prospective follow-up of 8 patients with COVID-19, chest MRI ptovided evidence-based visualization of the recovery process in all cases, with a decrease or complete regression of the exudation component.

Conclusion. MRI of the chest with respiratory synchronization or with breath-holding can be used for early diagnosis of inflammatory lung lesions in COVID-viral pneumonia and for subsequent follow-up control, is not accompanied by radiation exposure and closely correlates with the results of chest CT recruited as a modern standard for the diagnosis of pneumonia.

Aim. To identify criteria for differential diagnosis between gastrointestinal stromal tumor (GIST) and gastric leiomyoma (GLe) in contrast-enhanced computed tomography (CECT).

Material and methods. We retrospectively analyzed CECT data of 65 patients with GIST and 19 patients with GLe. All cases were histologically and immunohistochemically proved. We evaluated tumor size, contours, growth type, extraorgan extension, invasion into the surrounding tissues, tumor calcification/ulceration/necrosis and regional lymph node status.

Results. Among 84 patients divided into two groups (65 patients with GIST and 19 with GLe, respectively) we found that tumor localization, heterogeneous enhancement, and intratumoral necrosis may be utilized for differential diagnosis. The prognostic value significantly increased with the use of relative density ratio (tumor density/ aorta density or tumor density/portal vein density in the arterial, venous, and delayed phases, respectively) compared to tumor density alone. It was found that malignant GISTs are characterized by a higher relative density ratio than leiomyomas in the venous phase.

Conclusion. We developed a prognostic model for differential diagnosis between GIST and GLe with a sensitivity of 90.8% and specificity of 89.5%. We created an online calculator that preoperatively determines probable tumor type (http://medstatistic.ru/giso.html).

Epithelioid hemangioendothelioma of the liver (EHEL) is a rare (1 case per 1 000,000 people) primary malignant neoplasm from the group of mesenchymal tumors. EHEL is the most aggressive representative of the hemangioendothelioma range with metastatic response and relapse rate, and therein is close to angiosarcoma.

The purpose of this publication is to summarize our own experience in comparison with published data and to describe a disease symptom that was not investigated before.

Materials and methods. We studied five cases of epithelioid hemangioendothelioma of the liver, confirmed by histological examination. All patients underwent standard computer tomography with bolus contrast agent.

Results. The analysis of the images revealed typical for this pathology symptoms such as local retraction of the liver contour, a specific contrast pattern – “the lollipop sign”. We have revealed a new symptom: “the beading sign”, which was detected in four of five cases. In three of five cases, this symptom allowed us to determine the nature of the disease before histological examination.

Conclusion. EHEL is a difficult disease to diagnose due to its rare frequency and similarity to other focal liver lesions. In aspect of radiology, it is advisable to focus on specific symptoms of this pathology: retraction of the contour, “lollipop-sign” and “beading-sign”.

We present the very rare clinical case of a 54-year-old man who was diagnosed on CT and MRI with a mixed cystic-soft tissue pancreatic lesion with septa and calcification, looking like a malignant tumor of pancreas. The preoperative diagnosis was uncertain because of unclear features of the mass. This tumor from the body and tail of pancreas was excised by means of laparotomy. The final diagnosis of a complicated hydatid cyst was confirmed on morphological examination.

Aim: to present a rare clinical case of multiple post-traumatic intra-abdominal splenosis in combination with type 2 macroamylasemia, chronic pancreatitis in a 27-year-old woman, clinically manifested like a palpable mass in the right iliac region.

Main results. In the first part of the article, a detailed analysis of the medical history is given, the results of archival imaging studies and the data of laboratory and instrumental examination at the time of treatment are presented. The literature review presents modern definitions of splenosis, as well as brief information about the anatomy and physiology of the spleen.

Conclusion. The diagnostic process requires a detailed analysis of the history of the disease, the performance of laboratory studies in combination with modern imaging studies, as well as a thorough study of the literature data.

Purpose: comparison of hemodynamic parameters of transaortic blood flow in patients with aortic stenosis depending on the bivalve or tricuspid structure of the aortic valve.

Materials and methods. A study of 180 patients with isolated aortic valve stenosis (AC) with two – and threeleaf structure was conducted. Patients were ranked into 3 comparison subgroups by the area of the effective AC opening from 4 to 1.5 cm2; 1.5 to 1 cm2 and less than 1 cm2. An echocardiographic study was performed with the calculation of all the necessary parameters for the study.

Results. The comparison subgroups were comparable in terms of effective orifice area (AVA), effective orifice area index (IAVA), body mass index (BMI), LV UO index, and LV FV (p > 0.05). However, the indicators Vmax, Gmean, and AT in patients with a bivalve AK structure in all comparison subgroups were significantly higher than in patients with a tricuspid structure. Comparison subgroup with AVA from 4 to 1.5 cm2: Vmax 2.8 ± 9 m/s and 2.5 ± 6 m/s p = 0.02. Gmean 18.6 ± 7.2 mm Hg and 15 ± 6 mm Hg p = 0.03, AT 82 ± 12 ms and 70 ± 10 ms p = 0.002. Comparison subgroup with AVA from 1.5 to 1 cm2: Vmax 3.7 ± 0.8 m/s and 3.5 ± 0.6 m/s p = 0.02. Average transaortic gradient 37 ± 10 mm Hg and 29 ± 5 mm Hg p = 0.04, AT 103 ± 11 ms and 94 ± 10 ms p = 0.02. Comparison subgroup with an effective area of less than 1 cm2: Vmax 5.7 ± 1.2 m/s and 4.7 ± 0.7 m/s p = 0.001, Gmean 54 ± 15 and 43 ± 11 mm Hg p < 0.001, AT 127 ± 20 ms and 112 ± 10 ms p = 0.002.

Conclusion. Echocardiographic indicators of Vmax and Gmean in patients with bivalve AC structure have higher values than in patients with tricuspid AC structure with a comparable opening area.

Despite the fact that most vascular surgeons in Russia rarely use magnetic resonance imaging (MRI) in their daily practice, today interest in this method of imaging among specialists in the world is steadily increasing. This is due to the desire of clinicians to have another non – invasive method for diagnosing hemodynamic disorders of both the arterial (Magnetic Resonance Angiography – MRA) and venous vascular bed (Magnetic Resonance Venography – VRA). The development of these methods today is associated with the solution of many technical problems, the development of special pulse sequences and post-processing methods for the resulting image. This literature review analyzes published scientific data on the methodology of MRI in relation to the vascular system and the choice of optimal scanning modes. Taking into consideration the fact that this material is intended primarily for vascular surgeons and phlebologists, and not radiologists, the first part summarizes the basic understanding of the physical phenomena underlying the MRI image, without which a thoughtful analysis of the advantages and disadvantages of MR-Angiography and the search for the most optimal scanning mode for MR-Venography is not possible. Based on the constant desire of clinicians to be self-educated, it seems that this part of the presented material will not be difficult to understand. When describing the developed contrast-free and contrast-free MRA methods, attention is paid to the traditional methods of image processing in 2D mode (TOF, PC) using pulse sequences: spin echo (SE), multi-echo (SE T2), turbo spin echo (TSE), fast Advanced Spin Echo (fast Advanced Spin Echo-FASE), gradient echo (Gradient Echo-GE, GRE) and inversion recovery (Inversion Recovery-IR). In addition, the focus is on the most modern solu tions, including: multiplantar reformatting (MPR), maximum intensity projection (MIP), subvolume maximum intensity, surface rendering (SR), volume rendering (VR) and virtual intraluminal endoscopy (VIE). For all the methods used today, MR-Angiography is shown to be specific and informative, with a detailed analysis of the advantages and disadvantages. The nuances of understanding the resulting angiographic image in T1 and T2-weighted images and the phenomena of “bright blood” and “black blood” are shown. Since the absence of information or a brief mention only about the possibilities of using MRI in the diagnosis of hemodynamic disorders in patients with vascular pathology in Russian scientific literature it seems that this material is relevant and will arouse some interest from various specialists. Of particular interest is the potential use of contrast-free and contrast – free MR Angiography in the study of venous pathology of the lower extremities and pelvis, especially with regard to timely and accurate diagnosis of deep venous thrombosis (deep Vein Thrombosis-DVT) and venous thromboembolism (Venous Thrombosis – Embolism – VTE), which occupy a special position in the structure of patients with chronic venous Disorders of the lower extremities (Chronic Venous Disorders-CVD).

The lateral position of the sigmoid sinus is a significant indentation of its sulcus into the lateral wall of the skull, the sigmoid sinus is located lateral to the antrum. This anomaly is rare, occurs in 5–10%. Computerized tomography of temporal bones is performed for all patients with chronic middle ear disease. CT of the temporal bones visualizes in detail the anatomy of the temporal bone. Preoperative diagnosis of lateral position of the sigmoid sinus is very important and determines the choice of a surgical approach to the middle ear during surgery. Clinical observation of a child (14 years) with cholesteatoma of the middle ear is presented in this article. CT tomograms visualized lateral position of the sigmoid sinus. However, the lateral position of the sigmoid sinus was not taken into account when choosing the surgical approach. A transcortical approach to the middle ear was chosen in this clinical observation. Therefore, there was the inevitable and unreasonable denudation of the sigmoid sinus, the difficulty in performing an operation due to the risk of injury. In the reoperation, surgical approach to the middle ear was performed through the tympanic cavity. This avoided dangerous contact with the sigmoid sinus and effectively remove cholesteatoma.

Rationale. Quantitative CT (QCT) bone densitometry with asynchronous calibration not require a phantom during the scan procedure. Based on calibration data it converts X-ray density in HU to bone mineral density (BMD). Given the large number of CT studies performed on patients at risk of osteoporosis, there is a need for a hands-on method capable of assessing BMD in a short period of time without tailored software or protocols.

Goal. To develop a method for QCT bone densitometry using an PHK (PHantom Kalium), to compare the volume BMD measurements with the QCT data with asynchronous calibration provided by software from a reputable developer.

Methods. The studies were performed at 64-slice CT unit with body scanning parameters. The BMD was measured using two techniques: 1) QCT with asynchronous calibration using software from a reputable developer; 2) QCT using a PHK phantom (QCT-PHK). For convert the HU to BMD values, we scanned the PHK phantom and calculate correction factor. Phantom contains “vertebrae” filled with potassium hydrogen phosphate in different concentrations. In both methods, the BMD values measured for LI–II, and sometimes for ThXII, LIII.

Results. The study enrolled 65 subjects (11 male and 54 female patients); median age 69.0 years. A comparison of the vertebrae BMD measured by QCT and QCT-PHK revealed a significant linear Pearson correlation r = 0.977 (p < 0.05). The Bland–Altman analysis demonstrated a lack of relationship between the difference in measurements and the average BMD and a systematic BMD; bias of +4.50 mg/ml in QCT vs. QCT-PHK. Differences in the division into groups osteoporosis / osteopenia / norm according to the ACR criteria for the two methods were not significant.

Conclusion. The developed asynchronous QCT-PHK method measure BMD comparable to the widely used QCT with asynchronous calibration. This method can be used for opportunistic screening for osteoporosis.

Purpose of research. The aim of the study is to evaluate changes in density, Agatston score, Volume and Mass scores of coronary calcium at different scanning parameters using phantom measurement.

Materials and methods. 8 1-ml insulin syringes filled with potassium hydroorthophosphate solution of different densities were used in the study. The syringes were placed at regular intervals into two phantoms: type 1 phantom – container filled with water; type 2 phantom – Chest Phantom N1 “LUNGMAN”. The phantoms were scanned with a Philips Ingenuity Elite CT 128 scanner using protocols with different voltages (80, 100, 120, 140 kV), amperage (27–45, 166, 330–400 mA), and slice thickness (0.625, 1, 2.5, 3 mm).

Results. Density and Agatston indexes were obtained at different scanning parameters (voltage, amperage, slice thickness) for different factors of calcification density in both phantoms. The results are presented as a table with mean density values, standard deviation (SD), Agatston score of coronary calcium, and scanning parameters.

Conclusion. The study demonstrates the influence of various scanning parameters on coronary artery calcium scoring results. The obtained information can be used in practice for more accurate quantification of coronary artery calcium, regardless of the scanning parameters.

The article presents the possibilities of the complex application of methods of radiation diagnostics: bone x-ray, dual-energy X-ray absorptiometry, computed tomography, positron emission tomography combined with computed tomography using fluorodeoxyglucose labeled with 18-fluorine (PET/CT with 18F-FDG) in a patient with multiple myeloma, which was treated in the amount of high-dose therapy with autologous transplantation of hematopoietic stem cells. The diagnosis was established immunohistochemically. The use of these methods allowed us to dynamically assess the pathological changes characteristic of multiple myeloma.