Background. Evaluation of the therapeutic effect of neoadjuvant chemoradiotherapy (nCRT) for rectal cancer (RC) is of prognostic value and allows to individually plan the type and extent of further surgical intervention. One of the most promising methods of MRI evaluation is magnetic resonance tumour regression grade (mrTRG) system. However, the reliability and safety of this method must be confirmed by the results of clinical trials and practical application.

Objective: to analyze our experience in the prospective use of mrTRG system and evaluate the additional contribution of diffusion-weighted images (DWI) to its diagnostic efficiency.

Material and methods. The mrTRG values were determined in 125 (including 30 with DWI) patients with locally advanced RC who received combined treatment with nCRT in Tsyb Medical Radiological Research Centre from 2015 to 2019. The obtained data were compared with the modified pathologic response based on Lushnikov’s definition, and the diagnostic parameters of differentiation of patients responding and nonresponding to nCRT were calculated.

Results. When the mrTRG system was used without DWI, the following sensitivity and specificity values as well as positive and negative predictive values were obtained: 75%, 60%, 70% and 67%, respectively, with DWI – 87%, 87%, 87% and 87%, respectively.

Conclusion. A prospective evaluation of the result of nCRT using the mrTRG system has moderate accuracy for stratification of patients responding and non-responding to nCRT, which requires the use of additional criteria for MRI scores to select patients who may receive less aggressive surgical treatment. Despite the small number of patients with DWI, we obtained higher values of the diagnostic parameters. In this regard, we consider it appropriate to use DWI when assessing the treatment response.

Objective: to clarify and systematize the causes that can induce focal artefacts in skeletal scintigraphy with ^99mTc-pyrophosphate (PyP), their semiotics, principles and methods of differentiation from bone pathology.

Material and methods. Results of skeletal scintigraphy from 1568 patients were analyzed. Scanning in “whole body” mode started in 3 hours after 740 MBq of radiotracer activity intravenous administration, and performed in anterior and posterior projections in continuous table motion mode at rate of 12 cm per minute. Single photon emission computed tomography/computed tomography was additionally performed when necessary.

Results. Focal artifacts were detected in 40 patients (2.55%) and were divided into “cold” and “hot” according to the nature of the bone system changes they simulated. “Cold” spots (n = 29) were the result of the shielding effect of metal accessories (n = 10), implants, endoprostheses (n = 18), and barium suspension residues in the large intestine (n = 1). “Hot” spots (n = 11) mimicking metastatic lesion of bone structures were the results of the projection effect of extraosseous uptake of ^99mTc-PyP (n = 9) or urinary contamination (n = 2). “Hot” spots in the projection of the upper pole of the kidney (n = 5) could be the result of both calicostasis (n = 3) and injury of the adjacent rib (n = 2). The high uptake of ^99mTc-PyP in thyroid nodule (n = 3) simulated a “hot” spot in the lateral part of the cervical vertebra. Abnormal accumulation of 99m Tc-PyP in the nipple-areola areas of the breast was projected onto the posterior segments of the ribs. Urinary contamination imitated focal pathology of the pelvic bones. To differentiate the focal pathology of the ribs and calicostases, the patients were examined in the standing position. The “mask in” program was used to clarify the localization and projection correspondence of “hot” foci.

Conclusion. Analysis of focal artefacts formation causes in skeletal scintigraphy contributes to an adequate assessment of the data obtained, allows to choose the necessary method for their diagnosis and to avoid false results of osteoscintigraphy.

Objective: to evaluate the role and place of MRI lung screening in the detection of pneumonia and patient routing.

Material and methods. 500 MRI tests were performed in the period from November 1, 2020 to December 15, 2020 on the basis of more than 20 diagnostic centers of the federal MRI-Expert network. Two groups were identified. In Group 1 (control, n = 50) MRI studies were compared with CT studies in a single time interval of 0–2 days; 25 patients had a positive PCR test for SARS-CoV-2 and 25 patients were conditionally healthy. In Group 2 (effective, n = 450) mediastinal MRI was performed with lung screening on Philips 1.5 T and Siemens 1.5 T devices. The statistical analysis of the medical data base was performed.

Results. During the study, mandatory and additional MRI scanning programs were identified: for Philips 1.5 T tomograph, the mandatory programs are sSSh_fb: tra and cor; THRIVE: tra (inhale/exhale); for Siemens 1.5 T – T2_BLADE: cor, tra, sag. When comparing the visual data of the control group (n = 25) with a positive PCR test in a single time interval of 0–2 days, the fact of detecting MR changes coincided with CT changes in 76% of cases (n = 19). The group of patients were examined by only one method – MRI-screening of the lungs (n = 475), pathological changes in the lungs were detected in 44% (n = 209). Localizations of the pathological changes were as follows: bilateral changes – 70.3% (n = 147), right-side changes – 19.6% (n = 41), left-side changes – 10% (n = 21); lower parts 26.8% (n = 26), average departments – 10% (n = 21), the upper divisions – 14.8% (n = 31), mid-lower 29.6% (n = 62), total – 18.6% (n = 39). The ranges of the area of lesion of the pulmonary parenchyma on MRI were graded according to MRI criteria into 4 groups (< 25%, 25 – 50%, 50 – 75%, > 75%). The collective radiation dose decrease was calculated for a group of patients (n = 450), which averaged 2.025 man-Sv for 1.5 months, of which 0.077 man-Sv were control studies.

Conclusion. Based on the results obtained, the analyses of the possibilities of the MRI method in displaying pulmonary changes was performed. The method of MRI screening of the lungs is recognized as a possible alternative to computed tomography for dynamic monitoring in conditions of a shortage of CT records or the inability to perform it, and as a tool to reduce the collective effective dose of radiation to the population.

Mucinous adenocarcinoma is a rare malignant tumor of the lung, which is accompanied by extremely scarce and nonspecific symptoms. This leads to an increase in the timing of its recognition, especially in young women. Given the poor prognosis of the pathlogy, the problem of its early diagnosis with histological and immuno-histochemical studies is extremely urgent. The presented clinical case demonstrates the possibilities of computed tomography with intravenous contrast enhancement in a young woman for the diagnosis of mucinous lung adenocarcinoma.

Two cases of postoperative diagnosis of chronic pulmonary aspergillosis are presented, which were previously regarded as malignant neoplasms. A decisive role in the detection of chronic pulmonary aspergillosis is played by computed tomography, but the diagnosis should be confirmed by laboratory tests. The importance of early diagnosis of chronic pulmonary aspergillosis is associated with high risk of complications during surgery without the use of antifungal drugs.

The review considers the problem of choosing the optimal tactical approach to primary emergency radiation diagnosis of injuries during polytrauma based on data on indications for use, advantages and disadvantages of modern methods and protocols of radiation imaging. Literary sources were searched in the MedLine/ PubMed and eLibrary databases published from 2009 to 2019.

The tactics of selective radiation diagnosis of polytrauma involves performing sequential studies (sonography, X-ray, computed tomography) of body areas in which damage is suspected by the mechanism of injury and clinical data, which limits the accuracy of the diagnosis and increases the duration of the examination. Primary multi-helical “whole-body”computed tomography including head, neck, chest, abdomen and pelvis examination, reduces the percentage of missed injuries, the duration of the examination and the time before emergency surgery, which can significantly reduce mortality in polytrauma. Its use is justified in patients with severe combined trauma if a high level of emergency hospital care organization is provided. Using “whole-body” computed tomography significantly increases the dose and economic costs, but the benefits of it for the survival of patients with polytrauma can outweigh the radiation risk and economic losses. Further development of technologies and protocols for multispiral computed tomography can significantly reduce the dose of radiation and the duration of the study. Clear and well-founded criteria for the selection of patients are needed for whom the use of “whole-body” computed tomography will be an effective strategy for radiation diagnosis.

The true causes of sexual disorders after radiation treatment of prostate cancer, among which the central role is occupied by erectile dysfunction, are still not fully clarified. The number of patients who undergo various radiation-exposure options as a radical therapy is steadily increasing, which makes the issue very relevant. This literature review provides up-to-date data on the most studied probable mechanisms of the erectile function status decline after radiation therapy for prostate cancer.