Objective: determining the neglected ankle fractures clinical stages based on the analysis of computed tomograms (CT) at various time from the injury and radiological findings in different types of ankle injury.
   Material and methods. An open randomized multicenter study included 48 patients with Weber type B and C ankle fractures (15 males, 33 females) aged from 27 to 68 years old (mean age 45 years old). The result of the CT analysis for each patient was the ratio of bone density on the damaged side to the bone density of the intact ankle. Next, the correlation was defined between the attitude and time from injury (in days) as well as diastasis (in millimeters) and age (in years).
   Results. Mean bone density in the period up to 15 days was 403.25 ± 63.74 HU, in the period between 15 and 32 days – 359.85 ± 71.34 HU, in the period more than 32 days – 271.91 ± 73.34 HU. Local bone density is inversely proportional to the time from injury (correlation coefficient –0.678) and the fracture gap (correlation coefficient –0.396). There was no significant dependence of local bone density on the patient’s age (correlation coefficient –0.177). Local bone density significantly (p = 0.05) decreased in the period of more than 14 days from the injury and was 80% and less from intact bone density in the period of more than 32 days from the injury (p = 0.0004). Signs of fracture healing appeared, in average, on the 28 th day after the injury with the fracture gap less than 1 mm.
   Conclusion. From the point of view of preoperative planning, neglected ankle fractures bone density critical points are 14 th and 32 nd days after injury.

   Objective: to estimate the possibilities and determine the diagnostic value of scintigraphy and single-photon emission computed tomography combined with computed tomography (SPECT/CT) in the assessment of the functional state of parathyroids in comparison with laboratory data in patients with secondary hyperparathyroidism (SHPT).
   Material and methods. The study consistently included 64 patients with the established diagnosis of SHPT due to the acquired vitamin D deficiency or with terminal chronic kidney disease (CKD), with the presence of ultrasound data and laboratory tests of calcium-phosphoric exchange indicators. Neck and mediastum nuclear study with 99mTc-methoxy-isobutyl-isonitrile (MIBI) was performed in the planar two-phase scintigraphy mode according to the standard protocol with an estimation of parathyroid visualization intensity, as well as in SPECT/CT performed 1 hour after MIBI injection.
   Results. In the group of patients with CKD as a cause of SHPT (n = 14), the most pronounced increase of parathyroid hormone (PTH) level (210.8 ± 103.0 vs. 107.0 ± 40.2 pg/ml in patients with vitamin D deficiency (n = 50, p < 0.001)) and phosphorus (mean 1.39 ± 0.51 mmol/l), as well as excess of normal levels of alkaline phosphatase (407.7 ± 338.1 units/l) were noted. In patients with vitamin D deficiency, impaired parathyroids according to SPECT/CT data was visualized in 8 % of cases, and in patients with CKD in 14.3 %. No significant differences in the mean levels of vitamin D in patients with (n = 46) and without (n = 4) modified parathyroids according to scintigraphy were detected: 26.06 ± 13.19 vs. 25.82 ± 18.80 ng/ml, respectively (p = 0.97). Differences in PTH and calcium levels were not observed: 91.3 ± 39.2 vs. 89.2 ± 29.5 pg/ml (p = 0.90), 2.53 ± 0.21 vs. 2.58 ± 0,15 mmol/l (p = 0.64), respectively.

   Conclusion. The neck SPECT/CT is a key method of topical imaging of impaired parathyroids in preoperative preparation of patients with SHPT caused by CKD. The method may have a diagnostic value in treatment-resistant patients with vitamin D deficiency and upper-normal PTH and calcium levels in terms of detection of the nodular form of parathyroid hyperplasia. The implementation of SPECT/CT after 1 hour after MIBI injection increases the sensitivity of the study.

   Objective: to determine, evaluate, and describe different radiological patterns of microbiologically identified nontuberculous pulmonary mycobacterioses (NTPM) based on multislice computed tomography data.
   Material and methods. The study included 102 patients with radiological signs of lung disease and different types of NTPM. Slowly growing types of NTPM were detected in 62 (60.8 %) patients, and rapidly growing NTPM – in 40 (39.2 %). The diagnosis was established considering a patient’s complaints, a specified case history, radiological and clinical laboratory data including microscopic studies of sputum from 63 (61.8 %) patients, bronchoalveolar lavage and different types of bronchial biopsies data from 19 (18.6 %) patients, samples of lung video-assisted thoracoscopic surgery from 17 (16.7%) patients, pleural fluid samples from 2 (1.9 %) patients, and oropharyngeal wash samples from 1 (1 %) patient. We used the Somatom Emotion 16 multislice computed tomograph (Siemens) and the high-resolution algorithm (HRCT) with 0.8 mm slice thickness and 1.5 mm slice increment.
   Results. The HRCT data were highly polymorphic and showed interstitial focal changes, different calibre bronchiectasis, conglomerates or cavities, involvements of vessels or pleural layers. In some patients, changes in the axial interstitium were accompanied by single small focal consolidations located either discretely or in small groups. Peribronchovascular spread of dissemination foci in NTPM was detected by HRCT as irregular infiltration of the axial interstitium (vasculitis type). Changes in the bronchial tree in NTPM were characterized by bronchiolitis symptoms (extensive thickening of bronchial walls, bronchioles) with development of the tree-in-bud sign predominantly in the subpleural lung regions. In some cases, bronchiectatic changes formed conglomerate consolidations of sublobular or lobular extent. Changes of the bronchial tree were detected by HRCT predominantly as signs of deforming bronchitis, cylindrical, varicose, or cystic bronchiectasis, either restricted or spread. Changes might be accompanied by single multi-dimensional cystic bronchiectatic cavities.
   Conclusion. Typical HRCT signs of NTPM are endobronchial and peribronchovascular spread of foci, development of multi-dimensional conglomerates, deforming bronchitis, bronchiectasis, and presence of single multi-dimensional cystic bronchiectatic cavities.

   Objective: to determine the high-resolution computed tomography (HRCT) signs and their combinations, suggesting the presence of fibrotic hypersensitivity pneumonitis (FHP).
   Material and methods. The study included 52 patients with pathologically verified diagnosis of FHP who were examined according to the 2021 consensus criteria. All patients had lung HRCT no more than 4 months prior to lung biopsy. The analysis of the changes revealed during HRCT was carried out by qualitative and semi-quantitative methods. The presence of individual signs, the degree of their severity (as percentage relative to the volume of the entire lung tissue) and the features of distribution in the axial and longitudinal planes were taken into account. To search for significant combinations of HRCT signs, a correlation analysis was carried out.
   Results. The most common HRCT signs in the examined group of FHP patients were reticular changes (96 %) and ground glass opacity (88 %). Most of the patients had signs that did not correspond to the picture of “typical FHP”, such as ground glass and emphysema. Relatively rare cases were centrilobular lesions (46.2 %) and mosaic attenuation (52 %), which are traditionally part of the “typical FHP” picture. In 22 cases (42.3 %) there were signs of emphysema, the presence of which significantly complicated the interpretation of HRCT data even in the cases of characteristic signs of FHP. Correlations of almost all HRCT signs were weak. The most common combinations of features were ground glass + reticular changes, emphysema + honeycombing, reticular changes + bronchiectasis. The combination of ground glass and reticular changes had a moderate correlation, but it has low specificity.
   Conclusion. The HRCT picture of changes in the lungs among patients with a morphologically verified diagnosis of FHP has important features. A weak correlation between the signs does not allow to identify their combinations that can help in the early diagnosis of FHP with sufficient reliability.

   Superior mesenteric artery syndrome, first reported by Karl Freiger von Rokitansky, is a rare disorder associated with the compression of the horizontal part of the duodenum between the mesenteric artery and the abdominal aorta. A rare clinical observation of the development of the superior mesenteric artery syndrome in a 19-year-old patient is presented to raise the awareness of doctors about this syndrome and the need for early diagnosis and treatment to prevent complications.

   Hyperpneumatization of the paranasal sinuses is a rare condition. Hypersinus, pneumosinus dilatans, and pneumocele are the three types of excessive pneumatization according to the traditional classification proposed by Urken et al. (1987). If in the first case, no treatment is required, but the latter two may be accompanied by aesthetic and/or functional disorders or may result in pressure effects on adjacent anatomical objects, therefore they require surgical correction. Maxillary sinus pneumocele is described in few publications. The presented case demonstrates typical clinical and radiographic signs of the maxillary sinus pneumocele, as well as hypersinus on the contralateral side. Cone beam computed tomography scans in combination with anamnestic and clinical data provide key information for the diagnosis of maxillary sinus pneumocele, as well as for differential diagnosis with other variants of their excessive pneumatization.

   The jejunal diverticulosis is rare and accounts for approximately 0.5–1 % of the general population. Diagnosis of the pathology is difficult even in the presence of symptomatic complications (perforation, abscess, peritonitis, sepsis, intestinal obstruction and bleeding), therefore, it is often overlooked or delayed, which requires high awareness and vigilance of physicians. Emergency surgical interventions are performed due to the lack of clear clinical symptoms and reliable radiological data in an average of 25 % of patients with complications of diverticulosis. In the presented case, multislice computed tomography (MSCT) with intravenous contrasting revealed multiple diverticula of the jejunum with reactively altered walls, infiltration of the adjacent cellular tissue and small gas inclusions, indicating diverticulum microperforation. Esophagogastroduodenoscopy (EGD) was performed which confirmed the jejunum bleeding, and was followed by laparotomy which confirmed multiple jejunal diverticula with microperforation and bleeding. Thus, timely MSCT in combination with EGD allowed to avoid complications of jejunal diverticulitis.

   A rare case of jejunal lipoma complicated by intestinal intussusception in a 71-year-old man is presented. Abdominal computed tomography revealed intestinal intussusception caused by the jejunal wall lipoma, allowed to timely make a diagnosis and perform surgical treatment.

   Skin melanoma is potentially the most dangerous form among all tumor skin lesions. According to statistics, melanoma accounts for about 90% of deaths. The cause of high mortality of patients is early metastasis. At the same time, melanoma metastases can be localized in almost all organs and tissues. In addition to local and regional metastasis to the skin, subcutaneous tissue and lymph nodes, metastatic melanoma of distant organs is not uncommon, and this dramatically worsens the prognosis of the disease. High-quality instrumental diagnostics at various stages of patient management (from primary diagnosis to treatment control) allow to reduce mortality and increase the overall survival of patients. Positron emission tomography in combination with computed tomography (PET/CT) has been used in the last decade as a dominant imaging method for initial staging, control of treatment and detection of progression or recurrence of various types of cancer, including melanoma. It is of great practical importance for predicting survival outcomes, assessing the risk of disease progression, as well as the effectiveness of radiation and systemic therapy. It is PET/CT that allows to simultaneously evaluate the condition of all organs and tissues with minimal radiation load being more sensitive and specific imaging method in comparison with ultrasound, CT and magnetic resonance imaging. PET/CT with ¹⁸F-fluorodeoxyglucose is the most effective method for early detection of asymptomatic melanoma recurrence. In addition to accurate setting the tumor process stage, this method is crucial to ensure adequate and effective treatment, which in turn will increase the life expectancy of this category of patients in the near future.

   Subchondral stress insufficiency fracture of the knee is a new type of fracture that occurs in people of the older age group (from 50–55 years old) when exposed to a normal load on weakened bone trabeculae. In Russian sources, there is few information about this type of fracture. This is primarily due to the fact that initially the world and domestic medical communities designated this type of pathology as “spontaneous osteonecrosis of the knee”. In recent years, this term has been revised abroad and replaced by a more suitable one – “subchondral insufficiency fracture”. The etiology of insufficiency fracture is based on many diseases and conditions that lead to bone tissue weakening (osteoporosis, collagenosis, rheumatoid arthritis, post-radiation changes in bones, etc.). The main method for diagnosing this type of fracture is magnetic resonance imaging, since it is able to detect a fracture at any stage (especially at an early one). According to modern concepts, the terms “osteonecrosis” and “subchondral insufficiency fracture” require completely different approaches to the treatment. In the presence of complications, a fracture of insufficiency of the knee joint condyles threatens with subchondral collapse and secondary osteoarthritis, which leads to disability of a patient. Given the relevance of this medical problem, the aim of the review is to show the current state of literature data on the issue.