Annotation. Fluorophores are widely used in fluorescence-guided surgery for malignant brain tumors. ¹¹C-methionine [¹¹C] MET-PET allows for precise delineation of brain tumor boundaries, but this method is not always available. We hypothesized that the quantitative fluorescence intensity induced by chlorin e6 might correlate with [¹¹C] MET-PET uptake in malignant gliomas.

Purpose. To evaluate the correlation between 11C methionine radiopharmaceutical uptake on preoperative PET and intraoperative chlorin e6 fluorescence intensity with pathological data from biopsy specimens in surgery for malignant glial brain tumors.

Materials and methods. This prospective study included adult patients with supratentorial malignant gliomas (WHO Grades III and IV) who underwent preoperative [¹¹C] MET-PET scanning and surgical resection of the tumor using fluorescence navigation with the second-generation chlorin e6 (Photoditazine). Regional [¹¹C] MET-PET uptake in the tumor was expressed as the ratio of the standardized maximum uptake volume to the uptake volume in the normal contralateral frontal lobe. Fluorescence intensity of tumor samples was measured ex vivo using RSS Cam Endo software and a fluorescence detection system. The Ki-67 proliferative activity index and IDH mutation status were assessed using pathological and immunohistochemical analysis.

Results. This prospective study included adult patients with supratentorial malignant gliomas (WHO Grades III and IV) who underwent preoperative [¹¹C] MET-PET scanning and surgical resection of the tumor using fluorescence navigation with the second-generation chlorin e6 (Photoditazine). Regional [¹¹C] MET-PET uptake in the tumor was expressed as the ratio of the standardized maximum uptake volume to the uptake volume in the normal contralateral frontal lobe. Fluorescence intensity of tumor samples was measured ex vivo using RSS Cam Endo software and a fluorescence detection spectrometric system.

Conclusion. In surgical treatment of gliomas, visible fluorescence induced by fluorescent substances correlates with high [¹¹C] MET-PET uptake, as well as with the degree of anaplasia according to pathological examination and a high Ki-67 index according to immunohistochemistry.

Objective. To investigate characteristic magnetic resonance imaging (MRI) findings of the brain in patients with hyperammonemic encephalopathy (HE) and to identify the main neuroimaging features of this pathology.

Methods. A prospective study analyzed brain MRI data from 15 patients with sepsis and clinically confirmed HE. Assessment of cerebral changes was performed using a standard MRI protocol. The following parameters were evaluated during the analysis: localization and signal intensity characteristics of the lesions on MRI, presence or absence of diffusion restriction, presence magnetic susceptibility artifacts, as well as reversibility of structural changes.

Results. Neuroimaging revealed pathological changes in all 15 patients. In 13 patients (86.7%) had symmetrical lesions of the insular cortex and cingulate gyrus; 1 patient (6.7%) had symmetrical lesions of the basal ganglia; and in 1 patient (6.7%) had cortico-subcortical lesions in the cerebral hemispheres. All detected lesions were characterized by hyperintense signal on T2-weighted and T2-FLAIR images. On diffusion-weighted imaging (DWI), cytotoxic edema was observed in all patients. Follow-up MRI was performed in all patients after treatment adjustment and renal replacement therapy, demonstrating marked regression of all noted changes, concurrent with normalization of serum ammonia, lactate, transaminases, sepsis markers.

Conclusion. The present study characterized the MRI semiotics HE in patients with sepsis and identified its key neuroimaging patterns. The bilateral insular‑cingulate pattern should be considered a potentially valuable neuroimaging marker enabling early verification of HE.

Objective. To systematize the ultrasound features of various fibrous cap (FC) states of carotid atherosclerotic plaques that determine the risk of ischemic stroke, based on an analysis of the morphological changes in its surface that occur during plaque destabilization.

Content. This manuscript summarizes data both from literature and the authors' own experience. The FC separates the lipid-necrotic plaque core from the vessel lumen and is the most vulnerable to damage structure. Its thinning, rupture, and ulceration reflect different states of plaque destabilization and underlie the new Carotid Plaque-RADS stroke risk classification. The morphological features of each state are described, the threshold values for FC thickness are discussed. Ultrasound criteria for thick and thin plaque caps, plaque rupture, and healed ulceration are presented.

Conclusion. In routine practice, FC thickness on ultrasound is assessed qualitatively using the “seen/not seen” basis without quantitative measurement. Ultrasound detects cap ruptures with high accuracy and ulcerations with moderate accuracy. Contrast enhancement, three-dimensional reconstruction, and low-velocity blood flow mapping could improve diagnostic accuracy. Assessing the plaque’s FC status together with plaque structure and degree of stenosis is advisable for improving risk stratification and personalizing patient treatment.

The aim of the study: To determine the risk factors and likelihood of developing postoperative atrial fibrillation (POAF) after aortic valve replacement (AVR) for severe aortic stenosis (AS).

Materials and methods. A multicenter retrospective-prospective study was conducted among 181 patients with severe AS who underwent isolated valve replacement using biological prostheses in 2019–2025. The subjects were divided into two groups: with postoperative AF (POAF) (n = 75) and a group without POAF (n = 106). The median age was 72 [67, 75] and 70 [67, 73] years (p = 0.206), respectively. Female gender was 49 (65.3%), 62 (58.5%) (p = 0.438).

Results. Risk factors for AF development in the early postoperative period were assessed using multivariate analysis. Statistically significant factors included: left ventricular diastolic dysfunction (LVDD) grade 2 (β = 0.90, p = 0.020, OR 2.5 (1.2–5.4)) and grade 3 (β = 1.4, p = 0.006, OR 4.0 (1.5–11.0)), presence of rhythm disturbances in the anamnesis before surgery (β = 4.04, p < 0.001, OR 57 (7–67)), and replacement of the aortic valve using implanted bioprostheses (β = 0.90, p = 0.028, 2.5 (1.1–5.6)). For further analysis of risk factors and calculation of the probability of occurrence of postoperative AF, the group including patients with POAF was divided into two subgroups: individuals with the presence of cardiac arrhythmia in the anamnesis before surgery (n = 32), and without arrhythmia in the anamnesis in the preoperative period (n = 43). In the group of patients with no preoperative cardiac arrhythmia, the presence of grade 2 LVDD, grade 3 LVDD before surgery, a biological suture prosthesis, and female gender were statistically significant risk factors for developing POAF. In the group with in the anamnesis preoperative cardiac arrhythmia, there were no other statistically significant risk factors for developing POAF, and the odds of developing POAF increased 57-fold at baseline. If a patient had grade 3 LVDD at baseline and a biological suture prosthesis was used, the risk of developing POAF increased regardless of gender.

Conclusion. Preoperative risk factors for the development of AF in the early postoperative period in individuals who underwent surgical correction of severe AS and did not have cardiac arrhythmia preoperatively were: LVDD grades 2 and 3, female gender, and bioprosthetics using implanted prostheses. The presence of paroxysmal AF or frequent atrial extrasystoles before surgery is the main risk factor for the development of POAF. The likelihood of developing AF in the early postoperative period after coronary artery bypass graft replacement for severe AS significantly increases in the presence of the above-mentioned risk factors.

Computed tomography with intravenous contrast enhancement (CT with IV-CE) is the “gold standard” for diagnosing pancreatic lesions. Supplementing standard CT with IV-CE with a perfusion scanning protocol significantly enhances the diagnostic capabilities of imaging techniques in identifying the most informative intratumoral biopsy sites based on blood flow measurements, which in turn reduces the number of false-negative results in suspected pancreatic malignancy. This article presents the methodology for performing NDPCT of pancreatic lesions, post-processing of the obtained results, as well as the technical aspects of performing percutaneous targeted biopsy of pancreatic lesions based on NDPCT data under ultrasound control in fusion mode.

Objective: A detailed description of the methodology for performing and parametrically analyzing the results of low-dose perfusion computed tomography for the subsequent use of the obtained data for navigation during percutaneous targeted biopsy under ultrasound control in fusion mode of pancreatic tumors suspicious for cancer.

Materials and methods. These methodological guidelines are based on the results of original research conducted on 34 patients with pancreatic lesions who were treated between 2023 and 2026 at the Department of Surgical Treatment and Antitumor Drug Therapy for Abdominal Malignancies (incorporating abdominal surgery beds) of the Russian Scientific Center of Radiology and Surgical Technologies (RNCRR) of the Ministry of Health of Russia.

Differential diagnosis of solid renal tumors at the stage of standard radiological search is associated with a high frequency of overlapping imaging features, forming “gray zones” between benign and malignant histotypes.

Objective: to develop and validate a two-tiered differential diagnosis system for solid renal tumors based on the integration of literature data and analysis of our own clinical data (395 patients).

Materials and Methods. Based on a systematic analysis of metadata from 42 specialized publications (12,000 patients), the primary criteria of the model were formulated. Clinical testing of the algorithm was performed on our own sample of 395 patients, including clear cell carcinoma (ccRCC; n = 258), angiomyolipomas (AML; n = 35), papillary carcinoma (pRCC; n = 32), oncocytomas (n = 30), chromophobe carcinoma (chRCC; n = 28) and a control group of Bosniak IIF/III dense cysts (n = 12). All patients underwent ultrasound with color Doppler imaging, multiphase MSCT and multiparametric MRI (mpMRI). Mathematical analysis was performed using binary logistic regression and ROC analysis with bootstrap validation (B = 1000).

Results. A two-component code matrix for the calculator was developed, allowing for discrete separation of diagnostic stages over time. The first level (ultrasound + MSCT) automatically segregates up to 85% of classic patterns. If signs of a “gray zone” are detected, the session is archived under a patient ID until the second level (mpMRI) is performed. Differentiation of atypical tumors at the expert stage is achieved through the integration of functional MRI markers and the calculation of critical cutoff points for the measured diffusion coefficient (MDC) for polar histotypes. The overall diagnostic accuracy of the final two-level model on the validation set was 91.3%.

Conclusion. The two-level discrete approach minimizes diagnostic errors in “gray areas” of imaging, optimizes patient routing, and reduces the incidence of unnecessary surgical interventions.

The aim of the study was to consider the possibilities of using ¹¹C-choline PET/CT for visual and ultrastructural assessment of bladder wall barrier functions in women with late radiation cystitis.

Materials and methods. A comprehensive examination of four women with varying visual manifestations of late radiation cystitis was conducted. The affinity of the bladder wall for ¹¹С-choline was studied using PET/CT as the standardized uptake level of labeled molecules (SUV_max) coming from urine in combination with the results of scanning electron microscopy of all bladder wall elements in a single block.

Results. It was found that the affinity of the bladder wall for labeled ¹¹С-choline molecules in late radiation cystitis correlates with the severity of ultrastructural changes in its wall, which can be used as an additional marker of bladder barrier function integrity.

Conclusion. The clinical application of our developed computer program allows urologists to obtain a probable visual and ultrastructural 3D reconstruction of all elements of the bladder wall using the digital value (SUV_max) of ¹¹С choline PET/CT.

Objective: To evaluate the usefulness of the uterine arterial perfusion index (API) and uterine artery Doppler parameters for assessing uterine blood supply in the first trimester of pregnancy in women with a history of chronic endometritis and to determine their prognostic value for adverse outcomes in the first half of pregnancy.

Material and methods. Pregnant women (401) in the first trimester were enrolled and divided into a main group (with a history of chronic endometritis) and a comparison group (without evidence of chronic endometritis). Uterine artery Doppler parameters were assessed, and the uterine arterial perfusion index was calculated as an integral measure of uterine arterial blood supply. Analyses were performed separately for gestational windows of 5–7⁺⁶, 8–10⁺⁶, and 11–13⁺⁶ weeks. Nonparametric statistical methods with median differences and 95% confidence intervals were used. Prognostic performance was evaluated using ROC analysis.

Results. Across all first-trimester gestational windows, women in the main group demonstrated lower uterine arterial perfusion index values compared with the comparison group. The most pronounced differences were observed at 11–13⁺⁶ weeks of gestation, when API demonstrated the greatest magnitude of effect (AUC 0.92), exceeding that for velocity indicators and vascular resistance indices and high prognostic significance in relation to adverse outcomes in the first half of pregnancy. Resistance indices (PI, RI) were less consistent and more operator-dependent than the integral perfusion index.

Conclusion. The uterine arterial perfusion index is an informative integral parameter of uterine blood supply in the first trimester of pregnancy. A history of chronic endometritis is associated with reduced API and an unfavorable uterine hemodynamic profile. These findings support the potential use of API as a marker of early placentation conditions and for risk stratification of adverse pregnancy outcomes.

Background. Modern hybrid PET/CT technology with 2-[¹⁸F]fluoro-2-deoxy-B-glucose (¹⁸F-FDG) is widely used in multiple myeloma (MM) patients. However, a number of issues in the evaluation of PET/CT results require further analysis and systematization.

Aim: To investigate the role of FDG PET/CT in the diagnostics of MM.

Materials and Methods. The analysis included the results of 40 ¹⁸F-FDG PET/CT examinations performed in 40 patients with MM before therapy. To systematize the description of PET/CT findings, based on the analysis of fused images (including abnormalities on CT, PET or both) three types of lesions were identified: focal, diffuse, and diffuse-focal. The analysis included visual and semiquantitative assessment.

Results. In analyzed group (n = 40) 18F-FDG PET/CT showed focal lesions in 72% (n = 29) of cases, diffuse lesions — in 13% (n = 5), and diffuse-focal lesions in 15% (n = 6). In 33% (13/40) cases PET/CT results were ¹⁸F-FDG-negative – all focal lesions.

In the subgroup with focal and diffuse-focal type (n = 40), bone marrow lesions, according to ¹⁸F-FDG increased uptake without corresponding structural abnormalities on CT, were detected in 5% (2/40).

In the subgroup with osteolytic foci and plasmacytomas structural lesions showed significant differences in ¹⁸F-FDG uptake intensity – SUL_max values ranged from 1.6 to 22.2. This was observed both in the subgroups with focal and diffuse-focal type as a whole, as well as in individual patients, including lesions of comparable size.

Conclusion. The obtained results demonstrate significant polymorphism of changes detected by ¹⁸F-FDG PET/CT in MM patients at the diagnostic stage. Analysis of three PET/CT types of images – PET, CT, and fused – allowed for the identification of the main types of lesions: focal, diffuse, and diffuse-focal. The use of the proposed classification will allow for the standardization of PET/CT result descriptions and increase the accuracy of their assessment during follow-up studies in the course of MM patient treatment.

Preoperative differentiation of lipomas from atypical lipomatous tumors (ALT) of the extremities remains a relevant clinical challenge. On standard MRI assessment, these neoplasms demonstrate overlapping imaging characteristics, which complicates accurate diagnosis and may lead to suboptimal treatment strategies. Unlike benign lipomas, ALTs carry a potential for local recurrence and require wider surgical excision.

Contemporary approaches based on radiomics and machine learning enable the extraction of quantitative features from standard MRI sequences that reflect the microstructural properties of tissues, thereby offering opportunities for non-invasive diagnostic verification.

Objective. To develop and comparatively evaluate the diagnostic performance of machine learning models (LASSO logistic regression and Random Forest) built upon clinical-semiotic and radiomic features derived from non-contrast MRI (T1-WI and T2-WI) for the differential diagnosis of lipomas and atypical lipomatous tumors (ALT) of the extremities.

Materials and Methods. This multicenter, retrospective study included data from 61 patients with histologically verified lipomas and atypical lipomatous tumors (ALT) of the extremities. Tumor segmentation was performed on non-contrast T1-WI and T2-WI sequences, followed by extraction of radiomic features (n = 221) and assessment of clinical-semiotic parameters. The dataset was split into training (80%) and test (20%) subsets. Predictive models were constructed using LASSO logistic regression (10-fold cross-validation) and Random Forest (hyperparameter tuning via grid search). Model performance was evaluated by Accuracy, ROC-AUC, sensitivity, specificity, Precision, and F1-score. Comparison was performed using McNemar's test, DeLong's test, and bootstrap analysis (1,000 iterations). Differences were considered statistically significant at p < 0.05.

Results. On the test subset, LASSO logistic regression achieved an ROC-AUC of 0.889 (95% CI 0.694-1.000) and an accuracy of 0.692 (95% CI 0.434-0.950); sensitivity was 0.250, specificity 0.889, and F1-score 0.333. The Random Forest model yielded an ROC-AUC of 0.833 (95% CI 0.533-1.000) with an accuracy of 0.692 (95% CI 0.440-0.944); sensitivity and F1-score were 0.000 at a specificity of 1.000.

McNemar's test revealed no statistically significant difference between the models (p = 1.000). DeLong's test likewise showed no significant difference in ROC-AUC values (p = 0.771). Bootstrap analysis (1,000 iterations) confirmed the stability of the metrics: for LASSO, the mean ROC-AUC was 0.892 ± 0.101 and accuracy 0.691 ± 0.131; for Random Forest, 0.832 ± 0.153 and 0.685 ± 0.125, respectively.

LASSO regression selected 12 features of highest importance, comprising semiotic characteristics (“Hyperintense signal on FS”, “intra-/extra compartmental location”, “Shape”, “Number of septa”, “Presence of solid tissue”, “Septal thickness”) and radiomic parameters (Coarseness, Maximum2DDiameterColumn, VoxelVolume, ShortRunLowGrayLevelEmphasis.1, MeshVolume, Maximum2DDiameterColumn.1).

Conclusion. In this study, LASSO logistic regression and Random Forest models constructed from clinical-semiotic and radiomic features of non-contrast MRI (T1-WI and T2-WI) demonstrated comparable diagnostic performance in the differential diagnosis of lipomas and atypical lipomatous tumors of the extremities (ROC-AUC 0.889 and 0.833, respectively; p > 0.05).

The developed predictive models may prospectively serve as clinical decision-support tools, contributing to improved preoperative diagnostic accuracy and standardization of soft tissue lipomatous lesion assessment. Further validation on larger cohorts with external validation is required to confirm these findings.

Objective: To analyze the scientific literature on the potential of radiomics for predicting treatment response and outcomes in patients with head and neck cancers receiving systemic anticancer therapy and chemoradiotherapy.

Materials and Methods. A literature search was conducted in the PubMed and eLIBRARY databases using keywords related to radiomics, systemic therapy and head and neck cancers. Original articles published over the past 10 years and meeting the inclusion criteria were selected. Of the 56 publications initially identified, 13 studies were included in the final review after exclusion of irrelevant articles. These studies were based on CT, MRI, and PET/CT data. The analysis focused on radiomic model development methods, types of extracted features, and their prognostic and predictive value.

Results. The review demonstrated that radiomic models have substantial potential for predicting survival and treatment response to induction, palliative systemic therapy, as well as chemoradiotherapy. Combined clinical-radiomic models frequently were more effective compared with radiomic-only or clinical-only models. The use of machine learning and artificial intelligence algorithms was identified as a promising approach for optimizing prognostic models.

Conclusion. Radiomics represents a promising tool for personalizing systemic therapy in head and neck cancers, enabling improved prognostic accuracy and optimization of treatment strategies. Standardization of methodologies, validation of models in large cohorts, and reduction of technical heterogeneity across studies are required for successful clinical implementation.