INTRODUCTION: Congenital lung malformations are result of developmental disorders at any stage of organ formation. Manifestations of these changes vary significantly: from minimal in size to large space-occupying lesion of the lung, which can cause fetal death or severe postnatal respiratory disorders. In proper time and accurate prenatal diagnosis of lung development abnormalities is one of the fundamental factors determining management of pregnancy and prognosis.

OBJECTIVE: To demonstrate the most typical features of a wide range of congenital lung anomalies by ultrasound and MRI.

MATERIALS AND METHODS: The literature search was performed in open Russian and English databases Medline, PubMed, Web of Science, RSCI, eLIBRARY using keywords and phrases: «prenatal diagnosis», «fetal MRI», «ultrasound diagnostics», «сongenital lung malformations».

RESULTS: Based on literature data and our own experience in the use of ultrasound and MRI in diagnosis of сongenital lung malformations, the main signs of normal development and the most specific types of lung anomalies are described. Algorithm for diagnostic search for congenital lung malformations is presented.

CONCLUSION: Ultrasound is the main method for diagnosing congenital lung anomalies. Fetal MRI is used to clarify the nature and extent of changes, a more detailed assessment of adjacent organs, also to determine Multiple congenital anomalies. Understanding the characteristics of semiotics of lung malformations and the main signs of these anomalies is a fundamental criterion for prenatal counseling, as well as peri- and postnatal management of this category of patients.

INTRODUCTION: Whole-body magnetic resonance imaging (WB MRI) including diffusion-weighted imaging (DWI) is increasingly used in clinical practice. For metastatic prostate cancer, the radiologic reporting and data system Met-RADS-P (METastasis Reporting and Data System for Prostate Cancer) has been proposed to determine the prevalence of the metastatic process and subsequently evaluate the response to specific treatment based on WB MRI data.

OBJECTIVE: To present an overview of the methodological aspects of WB MRI in patients with metastatic prostate cancer in relation to the Met-RADS-P system, to outline its terminology and principles for assessing study results, and to discuss the possibilities of its clinical use.

MATERIALS AND METHODS: A search was conducted for publications for the period from January 1, 2017 to December 1, 2023 in Russian and English in the electronic databases eLibrary, Medline, PubMed, using the keywords: «диффузионно-взвешенная томография всего тела», «метастатический рак предстательной железы», «Met-RADS-P», «Whole Body MRI, WB MRI», «Whole Body DWI, WB DWI», «metastatic prostate cancer», supplemented by examination of references in the retrieved articles.

RESULTS: Based on the literature data and our own experience, WB MRI protocols in patients with metastatic prostate cancer are described, the algorithm of MR image analysis, the criteria for evaluating the response of metastatic foci in the skeleton, lymph nodes, and internal organs, and the response assessment categories according to the RAC (response assessment categories) scale, as well as summarize the results and discuss the prospects for the clinical use of Met-RADS-P.

DISCUSSION: The few publications in the literature using the Met-RADS-P system primarily concern the assessment of its reliability (inter-reader agreement). The authors conclude that it is appropriate to use it in monitoring metastases in patients with castration-resistant prostate cancer, emphasizing the clinical importance of identifying discordant responses after therapy. They also note the obstacles to the widespread introduction of WB MRI imaging into clinical practice, including the duration of the examination procedure and the large volume of diagnostic data that requires significant time for analysis and reporting, which can be overcome by automating the assessment of MR images using artificial intelligence.

CONCLUSION: The Met-RADS-P system systematizes the approach to performing and describing WB MRI in patients with advanced prostate cancer, allowing the technique to be reproduced on virtually any modern scanner, from the scan protocol to a standardized report of findings. This makes the WB MRI technique reproducible in a variety of medical settings, and therefore increases its value. Nevertheless, Met-RADS-P is a relatively new system and requires large multicenter clinical trials to confirm its efficacy and representativeness, as well as to level out its shortcomings.

INTRODUCTION: Glioblastoma and solitary metastases are the most common malignant neoplasms of the brain, characterized by high mortality and severe disability in patients. The method of choice for neuroimaging glioblastomas and metastases is contrast-enhanced magnetic resonance imaging. However, differentiation between the two is often difficult due to similar radiological features on MRI. Radiomics and machine learning can differentiate the primary origin of brain metastases and identify pathological tumor types noninvasively.

OBJECTIVE: Application of texture analysis for differential diagnosis of glioblastomas and metastases of different etiologies.

MATERIALS AND METHODS: 169 MRI studies from the RSCRR database were used in the study, 11 of which visualized morphologically differentiated glioblastoma of the brain, 55 lung cancer metastases and 103 breast cancer metastases. Segmentation of the regions of interest was performed semi-automatically in the free 3D-Slicer software with the ability to upload radiomic features from the regions of interest. For each lesion, 107 radiomic features were calculated from T1 and T2 sequences. Statistics: The calculation of statistical indicators was performed in a computer program for statistical data processing IBM
SPSS Statistics 23. In statistical data processing, the Mann-Whitney statistical criterion for quantitative indicators and correlation analysis using the Pearson criterion were used to reduce the feature space. The reduction of the feature space and the selection of predictors by the feature_importances measure based on decision forests were carried out. Machine learning models were built in Python 3.10 using specialized libraries.

RESULTS: For the model based on radiomic features extracted from T1 sequence, random forest showed the most efficient result, ROC-AUC=0.815 [0.749; 0.874]. For the model based on the radiomic features extracted from the T2 sequence, random forest showed the most effective result, ROC-AUC=0.817 [0.743; 0.873]. For the complex model based on radiomic features extracted from T1 and T2 sequences, random forest showed the most efficient result, ROC-AUC=0.855 [0.789; 0.906].

DISCUSSION: The classification models and their metrics obtained by us indicate that the radiomic features extracted from T2 weighted MR images make it possible to differentiate breast cancer metastases from lung cancer metastases with higher sensitivity than the features extracted from T1 weighted MR images. We also identified a large number of significantly different indicators in the construction of models for the differentiation of glioblastomas from metastases, which demonstrates the prospects of this direction. It is planned to continue the study with the expansion of samples. Our conclusions are also confirmed by the research results of our foreign colleagues.

CONCLUSION: The models we have obtained are highly accurate and sensitive to the differentiation of metastases of various etiologies and demonstrate significant potential in continuing this study with an expansion of samples.

INTRODUCTION: Non-small cell lung cancer (NSCLC) is a common cause of brain metastases (BM). Adaptive stereotactic radiosurgery (ASRS) may be a useful option in the treatment of patients with large unresectable brain metastases (BM), but to date there are only a limited number of studies evaluating the effectiveness of this method.

OBJECTIVE: To analyze the effectiveness of ASRS in patients with large BM NSCLC not subject to surgical resection.

MATERIAL AND METHODS: We retrospectively analyzed data from 37 patients suffering from NSCLC with 45 large (>2 cm in diameter, volume >4 cm3) unresectable BM treated with the Gamma Knife Perfexion model using two- and three-fraction ASRS. Of these, 14 foci (31.1%) were metastases of squamous cell lung cancer, 31 (68.9%) were metastases of adenocarcinoma. The median volume of lesions treated with ASRS was 9.8 (range 4.6–30.6 cm3). The dynamics of volume changes between fractions and the cumulative incidence of local relapses (CILR) were studied, and ROC analysis was performed for the tumor volume parameter. Intracranial progression-free survival (iPFS) and overall survival (OS) were assessed. Statistics: To establish statistical significance of differences for related variables, the Wilcoxon test for pairwise comparisons and the Friedman test for three or more groups were used. The Kaplan-Meier method was used to calculate local control, PFS, and OS rates. The log-rank test was used to compare survival data in two groups.

RESULTS: The median follow-up period was 19.4 months. With two-fraction ASRS, the median volume of metastasis decreased by 28.6% by the second session, with three-fraction — by 40.0% by the third session. The 1-year and 2-year CILR rates were 8.6±6.1%, respectively; 26.1±12.3%. In ROC analysis, the area under the curve (AUC) for tumor volume was 0.80 (95% CI 0.6– 1.0) with an optimal cutoff of 18.5 cm3. The differences in CILR between the groups with metastasis volume <18.5 cm3 and ≥18.5 cm3 were statistically significant (p<0.001). Median iPFS was 8.3 (95% CI 5.9–10.7) months, 1-year iPFS was 33.5±8.1%;2-year — 7.8±5.2%. Median OS was 13.2 (95% CI 9.0–17.4) months; 1-year OS — 52.9±8.7%, 2-year — 22.4±8.8%.

DISCUSSION: Using two- and three-fraction ASRS, we delivered doses to large BM sufficient for a high level of local control with an acceptable risk of neurotoxicity: 1-year local control was 91.4%; 2-year — 73.9%; the incidence of radionecrosis is 8.5%. A statistically significant effect of lesion volume ≥18.5 cm3 on the risk of local recurrence was found. The iPFS and OS indicators after ASRS can be considered satisfactory for this group of patients.

CONCLUSION: ASRS is an effective and perhaps optimal strategy for the treatment of large unresectable BM in patients with NSCLC, but comparison with other modern radiotherapy modalities such as stereotactic hypofractionated radiotherapy and WBRT with simultaneous integrated boost is needed.

INTRODUCTION: Orbital injuries account for 36 to 64% of all blunt trauma to the facial bones. Diagnosis of orbital wall fractures is carried out using conventional radiography in several projections and computed tomography; magnetic resonance imaging is less commonly used. Often, due to the small displacement of orbital bone fragments, X-ray diagnosis is difficult. Multislice CT with reconstruction of sagittal, coronal projections and 3D in the bone window in such cases is the best visualization method. However, there are still no clear indications for the use of each method and there is no complete view of the CT characteristics of orbital damage.

OBJECTIVE: To study the diagnostic value of computed tomography of orbital fractures in pediatric patients with acute trauma.

MATERIAL AND METHODS: Retro- and prospectively analyzed the results of CT scans of 94 patients with facial fractures from 01/01/2023 to 09/01/2023 to assess combined orbital injuries. Orbital fractures were detected in 63 children (67.0%). There were 44 boys (69.84%), 19 girls (30.15%) aged from 7 months to 17 years 10 months (average age 10.3). Statistics: For statistical analysis, the method of calculating the nominal correlation using the Kramer coefficient (V) using the IBM SPSS Statistics software package was used.

RESULTS: Concomitant injury was observed in 30 (47.6%); isolated 33 (52.36%). The number and frequency of fractures observed were as follows: superior wall of the orbit — 39 (61.9%); zygomatic complex — 19 (30.1%); lower wall of the orbit — 43 (68.2%); nasal bone — 17 (26.9%); lower jaw — 6 (9.5%); medial wall of the orbit — 28 (44.4%); upper jaw — 27 (42.8%); alveolar process — 6 (9.5%); isolated zygomatic arch — 14 (22.2%); Le Fort type I — 1 (1.5%); Le Fort type II — 2 (3.1%); and Le Fort type III — 0 (0%). Orbital hematomas were found in 25 patients (39.6%). It was revealed a strong correlation between the presence of contiguous skull fractures and multiple skull fractures (V=0.878, p<0.001), frontal sinus fractures and frontal sinus hemosinus (V=0.69, p<0.001).

CONCLUSION: Orbital fractures are a frequent type of facial fracture occurring in children with blunt isolated and combined trauma. In children with blunt trauma, head CT combined with clinical examination is currently the optimal tool for diagnosing clinically significant orbital injuries. There is a strong correlation between orbital hematomas and orbital vault fractures, orbital hematomas and lattice fractures, adjacent skull and orbital vault fractures, and adjacent skull and lattice fractures. CT examination should include multiplanar (in coronal and sagittal planes) and 3D reconstructions, which help to assess the extent of the fracture, the presence of diastasis, the degree of muscle impingement. Based on the data obtained, the clinician determines the need for surgical intervention.

INTRODUCTION: Topical diagnosis of pathologically altered parathyroid glands in patients with primary hyperparathyroidism is a challenge both for specialists of radial diagnostics and for planning the scope of surgical intervention. The choice of diagnostic modality for localization of parathyroid glands depends on the availability of the method for a particular medical center. PET/CT is a promising method to determine the localization of parathyroid adenoma

OBJECTIVE: To analyze the experience of using PET/CT with 11C-methionine and PET/CT with 11C-choline for preoperative diagnosis of parathyroid pathology in patients with primary hyperparathyroidism.

MATERIALS AND METHODS: 72 patients diagnosed with PHPT and underwent surgical treatment were included in the study. Before surgical intervention all patients underwent laboratory and instrumental investigations in the scope of: blood tests for PTH, TTH, ionized calcium, calcitonin, 25(OH)D, creatinine, phosphorus, ultrasound of the neck, computer tomography of the neck with intravenous bolus contrasting.

RESULTS: PET/CT showed the highest rates of DA in the patient group before primary surgery — 90.9%, compared with ultrasound (89.6%) and CT with IV contrast (84.9%). In the group of solitary adenomas of ectopic MTCS, PET/CT also had a higher DA — 92.8% than the other modalities. In patients with relapsed or persistent disease, the informativity rates of CT with intravenous contrast and PET/CT were similar (Se — 100%, Sp — 94.1%, DT — 96.2%).

DISCUSSION: The algorithm for preoperative evaluation of patients to identify the location of pathologic parathyroid glands now includes imaging with two modalities: Neck ultrasound and radionuclide imaging: planar scintigraphy (washout/subtraction), SPECT, SPECT-CT. If the results are questionable, a CT scan of the neck with contrast or PET/CT is performed as a second step. None of the modalities has 100% diagnostic accuracy. Our study demonstrated the superiority of PET/CT over ultrasound and CT w/in contrast in a group of patients scheduled for primary surgical treatment. In a small group of patients, high informative rates of PET/CT and CT with contrast were demonstrated before reoperation, confirming the great potential of these techniques in these patients.

CONCLUSION: PET/CT with 11C-methionine and PET/CT with 11C-choline have high diagnostic accuracy in patients with primary hyperparathyroidism before reoperation. PET/CT and CT with contrast showed similarly high diagnostic accuracy for the diagnosis of parathyroid adenoma with persistence or recurrence of the disease in patients with primary hyperparathyroidism.

INTRODUCTION: Previously we developed the computer aided detection system (CAD) for mammography MammCheck II that increased the detection rate of small and difficult to detect breast carcinomas (BC). However this system was not specifically designed for calcification detection and discrimination. On the other hand, the calcifications had no influence on the CAD capability to detect BCs that appeared as a focal lesions.

OBJECTIVE: To develop the approach for automated differentiation of benign and suspicious calcifications on the mammography images and assess its clinical value.

MATERIALS AND METHODS: For the developed software testing we used a set of 390 mammography images with calcifications of all possible types (278 images with benign and 112 images with suspicious calcifications). For classification we used linear support vector machine (SVM) model, that was trained on the set of 126 images (70 — benign and 56 — suspicious). We developed two SVM models: with no vascular calcification analysis and with it. Statistics: for comparison between the normally distributed samples we used the Student’s T-test, for non-normally distributed — Wilcoxon signed-rank or Chi-square tests. For correlation testing of normally distributed samples the Paerson coefficient was calculated, for non-normally distributed samples — the Spearman or Kendall correlation coefficients. The statistical significance corresponded to Р-values <0,05.

RESULTS: During the testing of the first model version with no vascular calcification analysis we discovered the similarity of small early vascular calcifications and the suspicious ones. As a result this model falsely classified 14 of 23 (60.87%) vascular calcification clusters as suspicious. Therefore the model was improved. The final discrimination results for all calcification types (both benign and suspicious) obtained with the help of improved model were the following: true positive conclusions — 375/390 (96.15%), false positive conclusions — 15/390 (3.84%). In both cases when suspicious calcifications were classified as benign the wrong results were een only on one mammography view. At the same time, on another view the suspicious calcifications were correctly classified.

DISCUSSION: During the CAD development it seems important not only mark the suspicious areas but also suppress false positive markings corresponding to the obviously benign lesions. However it is important during this operation not to suppress the true positive markings. Therefore such systems are inevitably characterized by a certain shift to decreased prognostic value of suspicious markings at the expense of the highest possible prognostic value of benign markings. In our viewpoint, the developed approach meets this requirement. Moreover, its integration into the CAD allows to suppress the markings of soft tissue lesions associated with typical benign calcifications, appeared on the previous processing steps. This capability may decrease the false positive rate of the main CAD module.

CONCLUSION: The developed approach to benign and suspicious calcification discrimination (version with vascular calcification analysis) on the mammography image provided the sensitivity — 98.21%, specificity — 95.32%, negative predictive value (benign marking) — 99.25%, positive predictive value (suspicious marking) — 89.43%.

INTRODUCTION: Perfusion computed tomography (PCT) is a contrast research technique that allows one to assess blood flow in the cortical and medulla layers of the renal parenchyma at the level of the microcirculatory bed, the influence of additional renal vessels and stenoses of the renal arteries on hemodynamics in the renal parenchyma.

OBJECTIVE: To optimize the technique of perfusion computed tomography of the kidneys. Determine the most informative indicators of perfusion in the renal parenchyma in the norm. Assess the relationship between perfusion parameters and the number of renal vessels, the presence of renal artery stenosis.

MATERIALS AND METHODS: PCT was performed in 46 patients with no anamnestic and clinical laboratory data on kidney disease who were undergoing examination for other pathological conditions, including 35 patients aged from 20 to 90 years (average age — 63.1 years) without hemodynamically significant stenosis and 11 patients aged from 64 to 94 years (mean age 80.3 years) with renal artery stenosis of 50% or higher. Perfusion indices were calculated using maximum slope and deconvolution algorithms, kinetic curves were plotted on a time-density graph, and color parametric maps.

RESULTS: A quantitative assessment of perfusion parameters in the cortical and medulla of the kidneys, a qualitative analysis of the state of its parenchyma on color parametric maps, and the shapes of kinetic curves on the time-density graph were analyzed. Changes in perfusion parameters were established depending on the age, number and condition of the renal vessels.

DISCUSSION: In the renal cortical layer, there was a predominance of indicators of blood flow velocity (BF), blood flow volume (BV), the rate of increase in the density of the contrast agent (CM) in the tissue (MSI), capillary wall permeability (PS) and lower values of the average transit time of the contrast agent (MTT) and the time to reach the maximum contrast agent density in the tissue (TTP) in comparison with the medulla. On the color parametric maps BF, BV, MSI, the cortical layer was characterized by intense red coloring, the medulla — yellow-green, on the TTP map green and blue coloring of the layers was determined, respectively. In elderly patients, there was a decrease in BF, BV with a concomitant lengthening of TTP in the cortical layer without changes in coloring on color parametric maps. On the density-time graph, the kinetic curve of the cortical layer was characterized by the appearance of a peak 10 seconds after the onset of the peak value in the abdominal aorta with further continuation of the curve in the form of a plateau; the kinetic curve of the medulla was characterized by a gradual moderate rise in the curve from 15 seconds after the start of scanning without the formation of peaks values.

CONCLUSION: PCT is an informative method for quantitative and qualitative assessment of perfusion in the renal parenchyma.

INTRODUCTION: The safety of magnetic resonance imaging (MRI) in patients with metallic foreign bodies is an important aspect that has been the subject of many scientific papers and guidelines. The issue of MRI in patients with implanted medical devices is well researched. However, for gunshot wounds, there are no clear guidelines for practitioners, and most recommendations are to refuse to perform the study if there is the slightest doubt about its safety.

OBJECTIVE: To systematize information on the safety and quality of MRI in patients with gunshot wounds and to develop practical guidelines for radiologists.

MATERIALS AND METHODS: We have analyzed and summarized the main domestic and foreign recommendations for ensuring safety during MRI, generally accepted classifications and mechanisms of gunshot wounds.

RESULTS: A review of physical risk factors in MRI, their causes, and recommendations for their minimization is presented. The influence of metallic objects on the appearance of artefacts on MRI images is considered. The algorithm of decision making on the safety of MRI in a patient with a bullet or shotgun wound is given. Two clinical observations are presented to illustrate the application of this algorithm.

CONCLUSION: Performing MRI in gunshot wounds is feasible but requires careful analysis of the risks and the importance of diagnostic information. Interviewing the patient in these situations is often uninformative, so radiography or CT are the methods of choice for detection of metallic foreign bodies. To minimize the risks of MRI, a scan protocol should be prepared in advance and the patient should be monitored after each pulse sequence.

INTRODUCTION: Subepithelial formations (SubEO) of the upper gastrointestinal tract (GI tract) are asymptomatic in most cases, and are a diagnostic finding in routine studies. Given the risk of malignancy of some SubEO, the question of treatment tactics remains relevant today: observation or surgical intervention.

PURPOSE: To demonstrate diagnostic capabilities at the outpatient stage when choosing observational tactics in a patient with SubEO.

MATERIALS AND METHODS: A dynamic observation of a 68-year-old woman with a randomly identified SubEO was demonstrated. The patient has been observed by a gastroenterologist since 2005 with a diagnosis of functional disorder of the gallbladder and sphincter of Oddi. In August 2022, when contacting the clinic with complaints of epigastric pain and heartburn, the following studies were performed: gastroscopy (FGDS), endoscopic ultrasound (EUS) with fine needle puncture, transabdominal ultrasound (TAUZI), computed tomography (CT) of the abdominal cavity, during which a submucosal formation of the stomach was diagnosed. The picture is more consistent with a gastrointestinal stromal tumor (GISO). Given the small size of the formation, the surveillance tactic was chosen. At the time of 12.2023, according to the results of control studies of the SubEO without dynamics.

RESULTS: The follow-up period was 17 months, the results of the control studies justified the wait-and-see tactics and allowed avoiding unjustified surgical interventions and intraoperative complications.

CONCLUSION: The combined use of TAUZI with endoscopy contributes to a better differential diagnosis and the choice of adequate treatment tactics.