INTRODUCTION: Diffusion-tensor magnetic resonance imaging (DT-MRI) is currently a well studied and applied in clinical practice technique. An important advantage of this technique is the measurement of fractional anisotropy (FA) values, which make it possible to quantify changes in brain matter. The authors are aware of publications on the study of FА values among children in small groups including only a part of ages. This work presents study of FA among large amount of examined children and notes values of FA for most of the significant structures of the brain in subjects from 4 months to 18 years of age.

OBJECTIVE: Analysis of the FА values of the anatomical structures of the brain in children of different age groups who did not reveal changes in the brain matter during multiparametric MRI, in order to further study the processes of development and myelination of brain structures, as well as the use of these values in clinical practice as reference values in the analysis of pathology.

MATERIALS AND METHODS: 153 patients aged from 4 months to 18 years were examined. MRI of brain was performed on the recommendation of the attending physician in accordance with clinical indications in case of suspected infection in the paranasal sinuses and neurological complaints, without focal symptoms. Distribution of examined children by age groups was: up to 1 year (infant age) — 6 children (3.9%); from 1 year to 3 years (early childhood) — 14 children (9.15%); from 3 to 7 years old (preschool age) — 39 children (25.5%); older than 7 years (school age and older) — 94 children (61.45%). Distribution of the examined by gender: male children — 82 (53.6%); female — 71 (46.4%). DT-MRI was applied to all patients with measurement of diffusion in 15 directions, and then FА values were measured in 21 areas of the white and gray matter of the brain. The regions of interest (ROI) were arranged in accordance with the zones of the ASPECTS and PC-ASPECTS scales adapted for the purposes of this study. Statistics: processing of the received data was carried out using application programs: Microsoft Excel, Statistica 10 with an assessment of the normality of the distribution of values and the use of parametric and nonparametric criteria.

RESULTS: The highest mean numerical values of FA for all groups of children were found in the white matter along neural pathways: 0.66±0.04 for the internal capsule; 0.68±0.05 — in the white matter of the midbrain; 0.64±0.08 — at the level of the pons; 0.69±0.04 — in the cerebellar peduncles. The FA indices in the white matter of other anatomical regions are slightly lower: 0.50±0.08 — for white matter at the M4 level according to ASPECTS; 0.52±0.08 — in the occipital lobe at the level of the basal ganglia; 0.54±0.05 — in the temporal lobe. The lowest FA values appeared in the gray matter: 0.16±0.04 — in the caudate nucleus; 0.12±0.04 — in the gray matter at the M4 level according to ASPECTS. The most pronounced differences in FA in children of early childhood and school age appeared in the ROI located in the white matter of the cerebral cortex: in the area of M5 0.46±0.05 versus 0.54±0.05, respectively; in the area of M1 0.43±0.06 versus 0.51±0.06, respectively. At the same time, differences in FA in children of early childhood and school age in ROI located in the white matter at the level of stem structures are less pronounced: at the level of the pons 0.6±0.07 versus 0.64±0.07, respectively; at the level of the cerebellar peduncles 0.68±0.04 versus 0.69±0.04, respectively. These numerical indicators illustrate and additionally confirm the known ideas about the development and formation of neural pathways and about the processes of their myelination. They also reflect the known data on the structural and functional differences between the gray and white matter of the brain. A significant increase of the FА values in children older than 7 years was determined in comparison with groups of younger children in the white matter of the cortical structures of the brain. At the same time, there are no significant age-related differences of FА in the region of brainstem. It was also found that in preschoolers, compared with children from 1 to 3 years old, white matter FА increases in the region of the caudate nucleus and midbrain.

CONCLUSION: The obtained normative values of FА can later be widely used in clinical practice as reference ones when performing DT-MRI and assessing neuroinfectious and other pathological changes in the brain matter in children. The revealed differences in age groups indicate an earlier development of brainstem structures, while the subcortical-cortical areas of the cerebral hemispheres develop and myelinate over a longer time.

INTRODUCTION: Pineal cysts are a common finding on brain MRI, but their which remains unclear. A theory has been put forward that non-occlusive cysts can compress the deep cerebral veins, leading to intracranial hypertension.

OBJECTIVE: Тo study the variant MRI appearance of the pineal gland.

MATERIALS AND METHODS: 48 volunteers underwent an MRI examination using a 1.5 T Toshiba Exelart Vantage device to assess the presence of MRI signs of central venous hypertension, taking into account the morphological variants of the pineal gland structure, and a category was assigned based on the calculated tectum-splenium-cyst ratio and thalamic coefficient. The mean age of men was 41.27±4.63, of women — 31.5±2.58 years. The study participants were divided into three groups: the 1st group — no pineal cyst, the 2nd group — pineal cyst less than 10 mm, the 3rd group —a cyst larger than 10 mm.

RESULTS: Based on the obtained tectum-splenium-cyst ratios and the ADC coefficient, it was found that in the volunteer group with cysts larger than 10 mm, 8 out of 15 people were at increased risk of developing central venous hypertension (categories 3 and 4). Category 4 patients had the narrowest aqueduct (1.1–1.2 mm). In the 2nd group, in persons with a pineal cyst less than 10 mm, there were no signs of aqueductal stenosis or tectal plate compression. In the 3rd group, in persons without a pineal cyst, there were also no signs of aqueductal stenosis or tectal plate compression, however, category 3 was assigned to 8 volunteers, which may be due to other causes of venous outflow impairment.

CONCLUSION: A large pineal cysts occur in younger patients, and in the presence of aqueductal narrowing and an increased risk of venous hypertension may cause clinical manifestations such as headaches, dizziness, and sleep disturbances. When patients present with relevant complaints, categorization based on DWI and SSFP is an additional criterion that reflects the degree of impact of the pineal cyst on adjacent structures. 

INTRODUCTION: Since 2020, the number of patients with complications after a new coronavirus infection (COVID-19) has increased, including mycoses. Mucormycosis ranks third in the frequency of detection among invasive mycoses in patients with reduced immunity. Acute and chronic invasive fungal rhinosinusitis is the most severe and dangerous variant of the disease.

OBJECTIVE: To analyze the features of the osteodestructive process of invasive mucormycosis, its relationship with blood supply, the dynamics of the process under the influence of treatment.

MATERIALS AND METHODS: The study evaluated changes in the bone structures of the skull, soft tissues of the facial region, brain, and thorax in a group of 10 patients (62.3±11.4 y.o.) examined in the clinic of maxillofacial surgery and the clinic otorhinolaryngology in the post- covid period. The results of cone-beam computed tomography (Sirona) of the maxillofacial region, Xray computed tomography Optima 540 CT (General Electric) of the maxillofacial region and thoracic cavity organs, magnetic resonance imaging (GE Signa HDxt) of the brain and maxillofacial region with intravenous administration of a paramagnetic contrast agent were analyzed.

RESULTS: In all cases, osteolytic lesions as a classical manifestations of invasive mucormycosis, were revealed in: alveolar processes of the upper jaws and walls of the maxillary sinuses in 100% of cases; palatine processes — 90%; nasal septum, walls of the ethmoid sinuses and walls the orbits — 70%; walls of the sphenoid sinus — 50%; pterygoid processes and zygomatic bone — 40%; the body of the sphenoid bone, nasal bones, frontal bones — 30%; the alveolar part of the mandible and temporal bone — 10%. All patients underwent surgery with resection of the affected bones — 100%, while 7 out of 10 patients received antimycotic therapy. When assessing the revealed changes in dynamics in all patients in the long-term postoperative period, sclerosis of small foci of destruction, a decrease in the extent of bone defects, a decrease in the size of sequesters, hyperostosis of the walls of the paranasal sinuses, cells ethmoid sinuses of the after sequestrectomy were noted. There were no fatal cases among the 10 patients we observed at the time of publication.

CONCLUSION: The combination of anatomical features and the state of blood supply contributes to the development of invasive mucormycosis of the bones of the facial skull and the RCT data help with determining treatment tactics, the volume of surgery, and assessing dynamics in the early and long-term postoperative period.

INTRODUCTION: Introduction of breast cancer screening programs has led to an increase in detection of non-palpable masses requiring core needle biopsy. Masses that fall into B3 category based on the histological results of core biopsy specimens, are of interest precisely because of their uncertain malignant potential and the lack of a final consensus on their management.

OBJECTIVE: To analyze the 3-year experience of ultrasound guided vacuum-assisted biopsy (VAB) in patients with B3 breast lesions based on the results of histological examination of core biopsy specimens.

MATERIALS AND METHODS: Between June 2019 and June 2022, 163 VABs were performed. The study group included patients with category 2–4 breast lesions according to the BI-RADS scoring system. The decision to perform VAB was made by the oncologist in each specific case on the basis of anamnesis, clinical data and the results of core biopsy histological examination: in cases of B3 or B2 lesions with a discordant radiologic pattern.

RESULTS: In 155 (95.0%) cases, the removed lesions were benign, invasive cancer was detected in 2 (1.2%) cases, ductal cancer in situ in 6 cases (3.8%). The сomplications included: in 5 (3.1%) cases, patients had pain after the procedure, and in 37 (22.7%) cases there was a hematoma. In 5 (3.1%) patients, residual tissue was found at the site of removed lesions. CONCLUSIONS: VAB is a safe alternative to exploratory surgery in patients with B3 lesions diagnosed by core biopsy.

INTRODUCTION: This article presents the results of application of CT densitometry in the computed tomography (CT) of the chest to diagnose various forms of pulmonary hypertension.

OBJECTIVES: To determine the diagnostic value of CT densitometry using comparative analysis of lung tissue density in patients with various forms of pulmonary hypertension.

MATERIALS AND METHODS: The study included 528 patients diagnosed with pulmonary hypertension by means of right heart catheterization (RHC) of the National Research Cardiac Surgery Center, Republic of Kazakhstan. All patients were divided into 4 groups according to the classification of pulmonary hypertension of the World Health Organization (ESC/ERS Guidelines) from 2015. The first group included 254 patients with pulmonary hypertension pulmonary hypertension due to left heart disease (PHLHD). The second group included 210 patients with pulmonary arterial hypertension (PAH). The third group included 49 patients with chronic thromboembolic pulmonary hypertension (CTEPH). The fourth group — 15 patients with pulmonary hypertension due to respiratory disease (PHDRD). The mean age of the patients was 52.15±16.75 years. Contrast-enhanced chest CT imaging performed with a 64-slice multislice computed tomography system (Somatom Definition AS, Siemens) with post-processing to assess the lung tissue densitometric parameters, analyse the diameters of the pulmonary trunk and its main branches. The CT examination was carried in accordance with an «Embolism» protocol with intravenous administration of a contrast agent according to indications. Statistics: analysis was conducted using the Statistica 10 software. To quantitatively compare the two groups nonparametric Mann-Whitney test and the Kruskal-Wallace test were applied. Mean value and standard deviation in the format of «M±S» were used for quantitative parameters. Correlation analysis was carried out using Spearman’s nonparametric rank correlation.

RESULTS: In patients with severe pulmonary hypertension a tendency for fibrotic changes was most clearly observed in cases of pulmonary hypertension due to left heart disease (–809.92±26.52), and emphysematous changes in the pulmonary arterial hypertension group (–843.27±43.88).

CONCLUSION: CT lung densitometry should be performed in all patients with suspected pulmonary hypertension as an additional method of examination.

INTRODUCTION: COVID-19-associated gastrointestinal tract involvement has been reported in 11.4–61.1% of cases. However, there is no data on the incidence of COVID-19-associated pathology in different parts of the gastrointestinal tract, and there’s little understanding about the appearance of COVID-19-associated gastrointestinal lesions on ultrasound diagnostic images.

OBJECTIVE: To study of the radiologic pattern of COVID-19-associated changes in the gastrointestinal tract based on the comparison of ultrasound and morphological autopsy data.

MATERIALS AND METHODS: The study was approved by the ethical committee of Gomel State Medical University (protocol № 2 of 24.03.2021). For the purposes of this study gastric and intestinal pathological examination was performed in 11 subjects (average age 64.6±10.1 years) who died of COVID-19 infection and 11 subjects who had no clinical or laboratory confirmed signs of COVID-19 infection (average age 67.2±8.8 уears). Using the ImageJ computer program, we determined the surface area of the whole studied object subject, and the affected areas (foci of hyperemia with fine-point hemorrhages), determined the percentage of organ mucosal lesions and also performed an ultrasound examination of the gastric and intestinal wall samples. Statistic: analysis was performed using the Statistica 10.0 software (StatSoft, Inc., USA).

RESULTS: The incidence of COVID-19-associated lesions in different parts of the gastrointestinal tract was as follows: stomach, 100.0%; duodenum, 25.0%; jejunum, 55.0%; ileum, 35.0%; cecum, 18%; ascending colon, 15%; transverse colon, 15% descending colon, 41% sigmoid colon, 55%; rectum, 75%. The lesion surface area in different parts of the gastrointestinal tract was as follows (%): stomach, 86,0 (75.0; 90.0); duodenum, 48,0 (39.0; 66.0); jejunum, 55.0 (50.0; 59.0); ileum, 35.0 (30.0; 41.0); cecum, 59.0 (55.0; 69.0); ascending colon, 34,0 (29.0; 41.0); transverse colon 36,0 (30.0; 42.0); descending colon 40.0 (34.0; 47.0); sigmoid colon 65,0 (61.0; 71.0); rectum 69.0 (65.0; 73.0). Ultrasound pattern in COVID-19-associated pathology of the gastrointestinal tract was uniform. Most often, foci of reduced echogenicity with indistinct and uneven margins were detected in the mucosa. Histologically, foci of lymphoid infiltration and formation of lymphoid clusters of B-lymphocytes were found in these areas.

CONCLUSION: The most frequent ultrasound pattern in COVID-19-associated gastrointestinal tract involvement is the presence in the mucosa areas of reduced echogenicity with indistinct and uneven margins.

INTRODUCTION: In recent years there is an increasing interest in assessing the state of the physis among pediatric orthopedic traumatologists, due to the availability of surgical correction of conditions associated with impaired growth plate function. Application of these methods requires dynamic assessment of the state of the physis. The existing methods for assessing the functional state of the physis are few and imperfect. Magnetic resonance imaging (MRI), in particular diffusion tensor imaging (DTI), is promising for assessing the growth plates.

OBJECTIVE: To assess the possibility of applying DTI technique to assess the state of the physis (growth plate).

MATERIALS AND METHODS: The study was approved by the local ethical committee of the Institute of the Human Brain named after N.P. Bekhtereva of Russian Academy of Sciences, protocol No. 32, dated 21.12.2020. Informed consent was obtained from each legal representative. At the Turner National Medical Research Center for Сhildren’s Orthopedics and Trauma Surgery of the Ministry of Health of the Russian Federation a standard magnetic resonance examination of the knee joints was performed, additionally diffusion tensor tomography was performed in 75 patients aged 4.1 to 14.3 years (41 males, 34 females), both deemed healthy and with a known physeal pathology. The studies were performed using a Philips Ingenia ElitionX machine with a magnetic field strength of 3 Tesla, DTI was performed in the coronal plane, TE=71.2 ms, TR=4000 ms, b-factor value 600 s/mm2, 15 diffusion directions were used, slice thickness was 3 mm without gaps, the matrix size was 1.25×1.25 mm. The resulting images were processed using the DSI Studio software, including tract construction, estimation of the total volume and average length of the tracts. The reproducibility of the technique was assessed.

RESULTS: Higher volumes and mean tract lengths were found in healthy males at puberty compared to other groups. When assessing reproducibility, the standard deviations were about 10% of the final value.

DISCUSSION: Images of growth plate tracts were obtained. In individuals of pubertal age that were deemed healthy, the tract volume values and the average length of the tracts were higher than in individuals of prepubertal age and those with pathological conditions affecting the state of the growth plates. The average tract length turned out to be more reproducible than the total tract volume parameter.

CONCLUSION: With the help of DTI, it is possible to evaluate the arrangement of the structures in the growth plates.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon disease characterized by heterogeneous clinical findings, absence of specific laboratory markers and good response to treatment. Typically CIDP manifests as weakness of varying severity, from minimal paresis to plegia, as well as symmetrical loss of sensitivity in all limbs, a distinctive clinical feature of CDL is the involvement of both proximal and distal parts of extremities. At the same time, there is a large number of atypical CIDP variants, clinically similar to other chronic disimmune neuropathies. Neuroimaging findings typically include involvement of the cauda equina, brachial, and lumbar plexus. The patient sought medical help complaining of weakness and loss of sensation in the extremities. This clinical case illustrates a combined involvement of cranial and spinal nerves, as well as spinal cord and brain in a patient with chronic inflammatory demyelinating polyneuropathy.

A new form of morphologically and molecularly distinguishable epileptogenic neoplasia with characteristic microscopic findings and a distinct DNA methylation signature as well as frequent genetic anomalies, was revealed in 2017; the tumor was called polymorphous low-grade neuroepithelial tumor of the young (PLNTY). Several specific radiological patterns found in PLNTY when compared with the results of a pathomorphological study being useful in differential diagnosis with other epileptogenic tumors were mentioned in certain papers. Our paper is devoted to some particulars of the radiological picture in two children with pharmacoresistant epilepsy who underwent epileptic surgery with histological verification of PLNTY.

Till now the facilities of MRI with paramagnetic contrast enhancement (CE-MRI) in detection of lung tumors remain underused and almost ignored. A clinical case of primary detection and prospective follow-up of lung cancer in a patient whose MRI of the chest revealed a tumor lesion — a central cancer of the left lung, in particular a lesion of the bronchus of the lower lobe of the left lung. MRI of the chest with paramagnetic contrast enhancement was carried out as part of the whole body CE-MRI study after the complex therapy of breast cancer, and both the primary lung tumor and metastatic lesion of mediastinal — subbifurcation lymph nodes were revealed. With a transbronchial biopsy, the diagnosis of lung cancer was verified. Chemotherapy (ChT) was started using the vinorelbin/ carboplatin regimen. After this, the CE-MRI has been carried out during the whole period of followup of anti-cancer chemotherapy. At the CE-MRI during the first course of ChT visually the complete regression of the disease, also with clinical remission was achieved. However, the ChT scheme was not fully completed due to the patient’s departure for urgent private reasons. Two months later, the patient was examined again according to the same CE-MRI protocol, while a relapse of the disease was detected with a more pronounced lesion of the mediastinal lymph nodes than during the initial treatment. ChT with vinorelbine/carboplatin was again carried out under the control CE-MRI, this time completely. According to the chest CE-MRI, visual remission was achieved, with the disappearance of nodular tumor at the site of the previously identified primary tumor of lung cancer and metastatic lesions of lymph nodes. Thus, it was the CE-MRI which provided the early diagnosis and adequate control of treatment of the lung cancer with extensive local lymph nodes spread. After this CE-MRI, the whole body PET with 18F-fluorodeoxyglucose (FDG) was also performed and no signs of relapse or continued tumor growth were revealed. Five months after this stage, the patient did persist to stay completely preserved clinically, at work and socially active. Thus, the chest CE-MRI can be employed for the follow-up of the tumor process in lung cancer, as necessary, without radiation exposure, without limiting the number and frequency of studies. 

Kaposi’s sarcoma in association with generalized tuberculosis is a rare combination of two opportunistic HIV-associated diseases, and the difficulties of their detection are especially relevant in the context of the COVID-19 pandemic. To demonstrate a clinical case of multisystem involvement by Kaposi’s sarcoma and pulmonary tuberculosis in a patient admitted to an infectious diseases hospital with suspected viral pneumonia caused by a new coronavirus infection COVID-19. The patient complained of general weakness, shortness of breath with minimal physical exertion, heavy sweating, cough with yellow-green sputum, fever up to 37–39°С, lack of appetite and weight loss of 13 kg over the past six months. The analysis of clinical data, laboratory, instrumental and pathoanatomical studies performed in a St. Petersburg’s infectious diseases hospitals was carried out. CT findings of generalized lymphadenopathy combined with lung infiltrates in a patient with a positive PCR test for a new coronavirus infection (COVID-19) led to the overdiagnosis of a lymphoproliferative disease and did not allow for Kaposi’s sarcoma to be detected in vivo due to the absence of typical CT findings of disseminated tuberculosis in the presence of bilateral pneumonia. Radiologists should be aware of the clinical picture and signs of Kaposi’s sarcoma, it must be included in the differential diagnosis if a patient has an atypical clinical presentation and course of the disease, in the presence of skin rashes, even with a positive PCR for COVID-19.

Urothelial cancer of the upper urinary tract is quite rare and accounts for 5–10% of all cases of urothelial cancer. Radiation research methods, primarily computer and magnetic resonance imaging, are leading in monitoring and detecting recurrence after surgery on the organs of the urinary system. A rare clinical case of recurrence of transitional cell carcinoma of the upper urinary tract in the ureteral stump is presented. The article, with an emphasis on radiodiagnosis, outlines a step-by-step follow-up of a patient with primary cancer of the upper third of the ureter (рT2N0M0), who was hospitalized in the city clinical hospital for pain in the right lumbar region. During dynamic contrast enhancement multiparametric MRI, a recurrence of the disease was established with a lesion of the non-removed stump of the right ureter. Semiotic MR signs of recurrence of transitional cell carcinoma of the upper urinary tract are described. The recurrent tumor of the ureteral stump was characterized by a moderate hyperintense T2WI MR signal and an isointense T1WI MR signal. Our data indicate lower ADC values in the tumor when measured by a large ROI (937 mm2, versus 796 mm2 ROI with a small size). The dynamic contrast enhancement performed in our study showed intensive accumulation of the contrast by the recurrent tumor.