Objective: to clarify and systematize the causes of focal and non-organ artifacts capable of acting as diagnostic pitfalls in lung perfusion scintigraphy using 99mTc macroaggregated albumin (MAA), as well as their semiotics, principles, and methods for differentiating from pathological changes.

Material and methods. The outcomes of lung perfusion scintigraphy were analyzed in 1,025 patients who underwent examinations to rule out pulmonary embolism (PE) or thromboembolic factors contributing to diagnosed pulmonary hypertension. The procedure was carried out in a multiplanar mode using twodetector single-photon emission computed tomography (SPECT) scanners while the patient was lying supine, 4–5 minutes after intravenous injection of a radiopharmaceutical (RPh) with an activity level of 111–148 MBq. Lung images were captured in six projections, including anterior, posterior, and four oblique planes. If required, additional screening was performed in combined SPECT/CT mode. The term “artifact” was used to describe isolated perfusion defects that simulate PE, as well as extrapulmonary findings resembling signs of a right-to-left shunt.

Results. Artefact scintigraphic findings corresponding to the above criteria were found in 634 (61.8%) patients. Focal changes (n=618) were classified into “cold” and “hot” based on their scintigraphic presentation. Single “cold” lesions (n=611) were most commonly due to the shielding effect of altered anatomical structures (heart – 493, pulmonary artery trunk – 72, pleural effusion and elevated diaphragm – 41), as well as implanted pacemakers (n=5). “Hot spot” (n=7) obscured thromboembolic perfusion defects because of their high specific radioactivity. The main reason for this artifact is blood ingress into a syringe with 99mTc-MAA during intravenous administration of RPh. Extrapulmonary signs of right-to-left shunt were observed in 14 patients with congenital heart defects and were characterized by concurrent visualization of the kidneys and other organs in the systemic circulation (spleen, liver, thyroid gland). The reason for artefactual intestinal imaging (n=2) was residual radioactivity following prior myocardial perfusion scintigraphy with 99mTc methoxyisobutyl-isonitrile.

Conclusion. Examining the reasons behind the occurrence of focal and extra-organ artifact findings in lung perfusion scintigraphy, as well as associated diagnostic and interpretive pitfalls, will enable the development of an appropriate quality control strategy to reduce the likelihood of false-positive interpretations of PE and systemic pulmonary shunts.

Objective: to prove the possibility of detecting pericardial contusion using computed tomography (CT) performed in the normal mode of chest examination.

Material and methods. The preliminary phase of the study examined the CT appearance of the intact pericardium, identified symptoms characteristic of contusion, and the likelihood of detecting these symptoms. The final phase assessed the potential of chest CT for detecting cardiac contusions in mine-explosive chest wounds.

Results. The ability to diagnose gunshot pericardial contusion using chest CT was established. Pericardial contusion was diagnosed in 45.1% of cases of mine-explosive chest wounds. The primary CT signs of contusion were pericardial edema and hemopericardium. Edema corresponded to pericardial leaflet thickening up to 2–3 mm. Pericardial thickness exceeding 3 mm indicated blood accumulation.

Conclusion. Detection of pericardial contusion by CT will help determine indications for in-depth examination of intracardiac structures.

Background. Kawasaki syndrome is a systemic vasculitis that mainly affects children under 5 years of age. Coronary aneurysms, which develop in 15–25% of untreated patients and can lead to myocardial infarction and sudden cardiac death, are particularly dangerous. The introduction of intravenous immunoglobulin reduced the incidence of this complication to 3–5%, however, 10% of patients show resistance to therapy. The growth of atypical forms and the appearance of multisystem inflammatory syndrome in children associated with COVID-19 increase the importance of accurate and timely diagnosis.

Objective: determining the role and place, studying the informative value of imaging methods in the diagnosis of Kawasaki syndrome and its complications in children.

Material and methods. For the period of 3 years from January 1, 2022, a retrospective analysis of the data of 16 patients with Kawasaki syndrome (mean age 3.5±1.8 years) was conducted. Echocardiography (EchoCG) was performed on a Philips EPIQ 7 ultrasound scanner using S5-1 (1–5 MHz) and S8-3 (3–8 MHz) sensors. The diameter of the coronary arteries and blood flow characteristics were evaluated. Computed tomography angiography (CTА) was carried out on a Canon Aquilion ONE 640-slice tomograph with bolus contrast agent injection and synchronization with electrocardiography. For suspected concomitant myocarditis, individual patients underwent heart magnetic resonance imaging (MRI) using a Siemens Aera 1.5 T device, which included obtaining T1and T2-weighted images, as well as assessing late contrast enhancement in myocardium after intravenous injection.

Results. EchoCG was performed in all 16 patients, CTА in 7, and heart MRI in 5. The proportion of patients with coronary aneurysms was 75% (12 out of 16). Combined lesion of several arteries was most often observed (58.3%). Dynamic follow-up after 6–12 months revealed a generally favorable prognosis: 27.3% of medium and 70% of small aneurysms remained without dynamics or regressed. However, 10% of small coronary aneurysms progressed, which underscored the need for careful, long-term monitoring of even small changes. The incidence of acute cardiac complications (acute coronary syndrome – 18.8%) in our cohort indicates a continuing risk of ischemic events. The differences in aneurysm sizes measured by CTА and EchoCG were not statistically significant (paired Student’s t-test: t(13)=1.09; p=0.297). At the same time, CTА revealed details critical for prognosis and tactics that were missed by EchoCG: an anomaly of the right coronary artery, mural thrombosis and calcification, as well as (in 1 case) the true extent of the lesion. Myocarditis was verified in 1 patient according to MRI data, namely, manifestations of left ventricular dilation and decreased contractile function, as well as edema signs by T2-tirm and late gadolinium enhancement, delayed accumulation of paramagnetic contrast agent of a characteristic non-coronary pattern.

Conclusion. EchoCG remains the method of choice in the acute period due to the early age of children. CTА is the most informative for assessing the distal sections of the coronary arteries and detecting complications (thrombosis, calcification, stenosis), while heart MRI is used to diagnose a combined inflammatory process. The optimal diagnostic strategy is aimed at detecting and dynamically monitoring the identified changes and should be based on a rational combination of these methods, taking into account the phase of the disease and age.

Background. Access to an objective quantitative assessment of esophageal transport function (ETF) is significantly limited in clinical practice due to two main factors: the insufficient availability of specialized equipment in healthcare institutions and the lack of adequate analysis techniques. The development of approaches utilizing conventional fluoroscopy with a liquid barium sulfate suspension contrast combined with automated processing has the potential to significantly increase the accessibility and objectivity of metric evaluation for patients with conditions involving swallowing disorders and esophageal motility impairments.

Objective: to develop and validate a proprietary algorithm for computer-based quantitative analysis of fluoroscopic images obtained from conventional esophageal fluoroscopy for the assessment of ETF in patients with related disorders.

Material and methods. A prospective comparative study included 34 patients with dysphagia (mean age 52.1±9.2 years). Each patient underwent modified fluoroscopy (a 60-second lateral video recording of the first swallow of 15 ml of standard barium suspension, corresponding to the first stage of contrast) and dynamic esophageal scintigraphy (DES) with 99mTc-technephyte, which was used as the reference method for quantitative parameters of mean esophageal transit time, based on our own results and literature data on quantitative ETF assessment. Fluoroscopic DICOM sequences were processed using the developed computer-based quantitative analysis of fluoroscopic images (QAFI) to generate intensity-time curves in selected regions of interest. The agreement between QAFI and DES results was assessed using dynamic time warping (DTW), cross-correlation, Bland–Altman analysis, and the intraclass correlation coefficient (ICC). Results. QAFI demonstrated high concordance with DES: mean DTW distance 0,055±0.012; synchronous crosscorrelation 0.925±0.06; ICC 0.915 (95% confidence interval 0.886–0.941). Bland–Altman analysis revealed no systematic bias (mean difference –0.01; limits of agreement –0.079 to 0.059). The diagnostic characteristics of QAFI were high: the area under the ROC curve was 0.94, with sensitivity of 0.90 and specificity of 0.88. The method's reproducibility was also high: intra-operator ICC>0,98, inter-operator ICC>0,97.

Conclusion. The developed proprietary algorithm for computer-based QAFI obtained by conventional fluoroscopy enables the acquisition of quantitative ETF parameters, demonstrating excellent diagnostic characteristics and good reproducibility. The obtained data confirm that QAFI could be a promising and widely accessible tool for use in routine clinical practice, as it is based on widely available fluoroscopy. The implementation of QAFI in clinical practice will facilitate a more objective and reproducible quantitative assessment of ETF in patients with esophageal motility disorders, expanding the capabilities of metric diagnostics without resorting to expensive techniques.

Background. Breast cancer remains the leading oncological pathology among the female population, which underscores the critical importance of methods for its early and accurate detection. Stereotactic biopsy (STB) is one of them: it is a minimally invasive procedure that provides histological confirmation of a diagnosis based on mammographic findings. However, its diagnostic performance when working with different subcategories of Breast Imaging Reporting and Data System (BI-RADS) requires further clarification in real-world clinical practice.

Objective: to evaluate STB diagnostic efficacy in detecting breast cancer in patients with suspicious mammographic findings (BI-RADS 4a, 4b, 4c, 5) in the context of correlation between radiologic conclusions and histological diagnosis.

Material and methods. A retrospective single-center study analyzed data from 102 patients who underwent STB. In 54 cases, STB results were compared with postoperative histological analysis findings. Key diagnostic performance indicators and the Cohen's kappa (κ) agreement coefficient were calculated.

Results. According to STB, malignant, precancerous, and benign processes were identified in 18.6% (19/102), 11.8% (12/102), and 69.6% (71/102) of cases, respectively. When compared with excision biopsy data (n=54), STB demonstrated the following metrics: diagnostic accuracy 90.7%, sensitivity 84%, specificity 100%, positive and negative predictive values 100% and 81.4%, respectively. The false negative rate was 9.2% (5/54). Agreement between the methods was very high (κ=0.85). The highest frequency of cancer confirmation was associated with the BI-RADS 4c subcategory.

Conclusion. STB has proven to be a highly accurate and effective method for the morphological verification of suspicious breast lesions categorized as BI-RADS 4–5, contributing to a reduction in the number of unjustified surgical interventions. The primary direction for further improvement of the technique is to reduce the frequency of false negative results by optimizing the tissue sampling procedure.

Background. Liver fibrosis represents a structural manifestation of chronic liver diseases and, with progression, leads to the development of cirrhosis and related complications. Native liver T1 mapping is considered a quantitative magnetic resonance imaging (MRI) technique reflecting the severity of fibrotic changes; however, its diagnostic performance may be influenced by liver tissue composition, including steatosis.

Objective: to evaluate the diagnostic performance of native T1 mapping for liver fibrosis staging and to assess the impact of steatosis on its diagnostic characteristics.

Material and methods. This retrospective study included 241 patients who underwent abdominal MRI with acquisition of native liver T1 relaxation maps using the MOLLI 4(1)3(1)2 and MOLLI 5(3)3 protocols with pulse-triggered cardiac synchronization during a single breath-hold. Reference fibrosis staging (METAVIR F0–F4) was established based on integrated clinical, laboratory, and instrumental data. An additional stratification was performed according to the presence of hepatic steatosis, determined based on proton density fat fraction values. Patients with evidence of hepatic iron overload were excluded from the analysis. The relationship between native liver T1 values and fibrosis stage was assessed using correlation analysis, and intergroup comparisons were performed across fibrosis stages. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis for the identification of clinically significant fibrosis (≥F2), advanced fibrosis and cirrhosis (≥F3), and cirrhosis (F4). Statistical analysis was performed using nonparametric methods. Multiple comparisons were controlled using the Benjamini–Hochberg procedure, and results were considered statistically significant at false discovery rate (FDR) <0.05.

Results. A statistically significant positive correlation was observed between native liver T1 values and fibrosis stage (ρ=0.779 for MOLLI 4(1)3(1)2 and ρ=0.792 for MOLLI 5(3)3; p<0.001; FDR<0.05). Median T1 values increased progressively from F0 to F4, and differences between all adjacent stages remained significant after FDR correction. ROC analysis demonstrated high diagnostic performance of native T1 mapping for fibrosis stratification: AUROC values for ≥F2 were 0.909 and 0.919; for ≥F3, 0.946 and 0.954; and for F4, 0.972 and 0.981 for MOLLI 4(1)3(1)2 and MOLLI 5(3)3, respectively. In the presence of steatosis, diagnostic performance decreased for ≥F2, whereas no statistically significant differences between subgroups were observed for ≥F3 and F4 (p>0.05). These findings indicate a modifying effect of steatosis primarily at early stages of fibrosis discrimination.

Conclusion. Native liver T1 mapping using MOLLI 4(1)3(1)2 and MOLLI 5(3)3 protocols is an informative quantitative MRI technique for fibrosis staging. Diagnostic performance increases from ≥F2 to ≥F3 and reaches its highest level in cirrhosis. The presence of steatosis reduces discriminatory performance for ≥F2, thereby defining the limitations of the technique and supporting its use as part of a multiparametric MRI approach in patients with chronic liver diseases.

Infiltrative pulmonary tuberculosis remains one of the most pressing problems in modern phthisiology due to its high prevalence, variability of clinical manifestations, and difficulties in early diagnostics. This clinical case demonstrates an algorithm for the diagnosis and treatment of infiltrative pulmonary tuberculosis in an adolescent. The criteria for differential diagnosis with pneumonia, the role of immunological and microbiological methods, and the dynamics of X-ray changes during tuberculosis therapy are considered.