COVID-19
Purpose. To assess changes in the degree of pulmonary injury in patients with Sars-CoV-2 after extracorporeal hemocorrection methods (ECHCM).
Material and methods. 27 patients with Sars-CoV-2 underwent 48 ECHCM procedures - plasma separation, nonselective cytosorption hemoperfusion, dialysis-filtration techniques. After arriving in the hospital all patients underwent MSCT of the chest organs. The examination was conducted according to the standard protocol of MSCT of the chest organs and reconstruction of soft and high-resolution on a Philips Ingenuity CT 64 multi- detector computed tomograph. The following scanning parameters were used for the standard protocol: 64 × 0.625 collimation, 1 mm reconstruction, 0.5 mm increment. The patient was lying on his back with his arms thrown back behind his head during the procedure. A scan area including the chest was planned by the plan scan. Assessment of the scans was carried out in the Diсom-images viewing module of medical hardware- software complex “ArchiMed” (Med-Ray. Russia, 2004). The percentage of lung parenchyma lesions as well as the severity (CT-1–4) were evaluated according to the recommendations “Radiation diagnosis of coronavirus disease (COVID-19): organization, methodology, interpretation of the results”. CT examinations were compared not earlier than 4 days before ECHCM and not later than 5 days after.
Result. With isolated plasmaseparation, the “ground glass” zones passed into the consolidation zones, the total volume of the lesion decreased and the pneumatization increased. In isolated hemoperfusion the dynamics is multidirectional: there are more consolidation zones, less ground glass zones in general, the process is stabilized and the zones of lung tissue damage are reduced. With isolated hemodiafiltration, the consolidation zones decreased, the pneumatization of the lung tissue increased, and subsequently the volume of the lesion and the consolidation zones increased significantly. By combined procedures there are multidirectional dynamics.
Conclusion. The effect of ECMGC use on the degree and volume of lung tissue damage in patients with Sars- CoV-2 was not revealed.
Item. To evaluate the features of CT imaging of the liver and the possible causes of pathological changes in COVID-19.
Materials and methods. An analysis of the literature and our own data on the features of CT imaging of the liver in combination with biochemical analyzes in patients with COVID-19 was performed. The main possible causes of changes in the liver, as well as symptoms with CT, are examined.
Results. The main target of the new SARS-CoV-2 coronavirus is the respiratory system. But among patients with COVID-19, along with damage to the central nervous system, myocardium, and intestines, cases of liver damage or dysfunction have been reported. This is expressed in an increase in biochemical markers of liver damage, as well as in a diffuse decrease in its density during CT, which is usually observed in the acute stage of the disease.
Aim. Compare radiological patterns of COVID-19 pneumonia with pulmonary histology in deceased patients.
Materials and methods. The analysis of recent lifetime CT studies of deceased patients was performed with the identification of all existing and leading CT symptoms, including “ground glass”, “crazy paving”, consolidation, as well as the symptom complex (pattern) of organizing pneumonia. Based on the CT symptoms, we selected the target points for taking the specimens by 3-D reconstructions. At the autopsy the lungs were entirely fixed into the front and then marked on CT sections cut from 1 to 3 pieces that were placed in paraffin and processed according to the standard technique, stained with hematoxylin and eosin and fuchsin-facelina. The specimens were analyzed by identifying all available histology changes and selecting the leading one.
Results. 45 targeted pieces of lung tissue were obtained from 14 deceased COVID-19 patients (7 men/ 7 women), with an average age of 77.1 ± 12.9 (49–90 years). In deceased patients with the presence of the "ground glass" symptom, in most cases (57.1%) revealed an increase in intra-alveolar cellularity, hyaline membranes, desquamation of the alveolar epithelium and infiltration of the interalveolar septum by lymphocytes, which corresponds to the exudative phase of diffuse alveolar damage (DAP). Mosaic histological changes with alternation of filled alveoli (intraalveolar edema, clusters of red blood cells, macrophages, lymphocytes) and air alveoli were detected from the areas of “crazy paving” zones. Several cases demonstrated interstitial edema and lymphoid infiltration of interalveolar partitions of different severity without their thickening. Areas of consolidation were histologically represented by extensive intraalveolar hemorrhages and / or typical zones of hemorrhagic infarcts in 45.5% of cases. Perilobular consolidation, subpleural cords, symptoms of “halo” and “reverse halo”, which we considered as part of the symptom complex of organizing pneumonia in 43% of cases, morphologically corresponded to organizing pneumonia (the proliferative phase of DAP), as well as to distelectases.
Conclusion. Comparison of CT patters and post-mortem pulmonary histology in COVID-19 deceased patients demonstrated that CT symptoms and patterns correspond to certain morphological changes of different phases of DAP.
ABDOMEN
Purpose of the study. Determination of normal thickness and contrast of the wall of the small bowel (SB) depending on the phase of digestion on computed tomography (CT).
Material and methods. We examined 358 patients aged 20 to 88 years. According to the results of the survey, patients are divided into two groups. The main group consisted of patients examined on an empty stomach (n = 329), and an additional group consisted of patients examined after eating (n = 29). A CT scan of the abdomen was performed with a cut-off thickness of not more than 2 mm and a bolus contrast enhancement (CE) with a nonionic contrast medium. The results of measurements of the wall thickness of the SB and the intensity of its contrast were subjected to grouping and statistical processing.
Results and discussion. According to the results of our study, the average value of the wall thickness of the SB is normally 3.1 ± 1.2 mm, with a tendency to decrease this indicator in the distal direction. The regularities of changes in the thickness and intensity of contrasting of the wall of the SB in the norm depending on the age and the last meal were determined. With increasing age, diffuse thinning of the SB wall occurs. Normally, after eating, there is a thickening of the SB wall to 4.6 ± 1.8 mm and an increase in the intensity of contrast, mediated by an increase in blood supply, with a density gradient of + 10%. After CE, the proximal sections of the SB are contrasting brighter than the distal. The gradient of contrastion of the proximal and distal parts of the SB increases after meals, is maximum in young patients and decreases with age.
Conclusion. In order to reliably differentiate the pathological thickening and change the contrasting of the SB wall from the physiological one, it is imperative to ascertain the time and nature of the last meal and to take into account the age of the patient. In "non-contact" patients, an indirect orientation is possible according to the degree of filling of the stomach and SB.
The incidence of focal lesions in the spleen is 3.2–4.2% per 100,000 population. Spleen cysts are rare (incidence 0.75 per 100,000). These are single or multiple, thin- and smooth-walled cavities filled with a transparent liquid. Distinguish between primary (or true) cysts, lined with epithelium, and secondary (or false), devoid of epithelial lining. Among the primary cysts, there are congenital cysts formed in the embryonic period due to the migration of peritoneal cells into the spleen tissue, dermoid and epidermoid cysts. A special group of primary cysts are parasitic cysts. Cystic tumors of the spleen include lymphangioma and lymphoma.
The main difficulties in the diagnosis and differential diagnosis of cysts and cystic tumors of the spleen are associated with the rarity of this pathology and, as a consequence, a small number of works, including a significant number of the cases. However, in those works where a large number of the cases are described, most often this is one morphological form and an analysis of its various characteristics.
Purpose. Based on the analysis of our own examination data of a significant number of patients with cysts and cystic tumors of the spleen, to assess the possibility of differential diagnosis of individual morphological forms according to ultrasound data.
Materials and methods. 323 patients with cysts and cystic tumors of the spleen from 15 to 77 years old (men – 105 (32.5%); women – 218 (67.5%) were treated at A.V. Vishnevsky National Medical Research Center of Surgery for the period from 1980 to 2020. All patients underwent ultrasound during examination. Surgical treatment was carried out in various ways – (85.1%), when making a preoperative diagnosis of an uncomplicated spleen cyst of small size, dynamic observation was carried out (verification by puncture biopsy data).
Results. Morphological verification of cysts and cystic tumors of the spleen was presented as follows (taking into account possible difficulties in identifying the epithelial lining): true cyst – 182 (56.4%); dermoid cyst – 3 (0.9%) (malignant – in 1 case); pseudocyst – 16 (5.0%); pancreatogenic – 34 (10.5%); echinococcus – 52 (16.1%); lymphangioma – 24 (7.4%); lymphoma – 10 (3.1%); ovarian cancer metastasis – 2 (0.6%). The article describes the ultrasound signs of the above forms of the lesions with an emphasis on the complexity of diagnosis.
Conclusions. Primary and parasitic spleen cysts are well differentiated according to ultrasound; false cysts of the spleen, depending on the cause of their occurrence, can create difficulties in their identification and differentiation (they require careful dynamic control); cystic tumors of the spleen should be differentiated from malignant tumors and metastases of a cystic structure, as a result of which such vigilance should always be present when they are detected.
THORAX
The aim of the study: to develop prediction comprehensive criteria for the diastolic dysfunction (DD) of the left ventricle (LV) according to 2D Speckle Tracking echocardiography (STE).
Materials and methods. A clinical and instrumental study of 91 patients aged 64.0 was performed [58.0; 70.0] years in the Minsk Scientific and Practical Center of Surgery, Transplantology and Hematology in 2019. Criteria for inclusion: sinus rhythm, essential arterial hypertension, chronic coronary artery disease, previous left myocardial infarction, after which at least six months have passed to stabilize the LV structural and functional parameters, chronic heart failure, patient informed consent. Exclusion criteria: primary mitral regurgitation, mitral stenosis, mitral valve repair or prosthetics, congenital heart defects, acute and chronic diseases of the kidneys, lungs. Transthoracic echocardiography and STE was performed on ultrasound machine Vivid E9 (GE Healthcare, USA).
Results. The leading functional anomalies, interconnected in the development of LV DD, are decline of the LV longitudinal diastolic, regional and global systolic strain, LV mechanical dispersion and dyssynergy. Correlations between LV DD type II and the mechanical dispersion index (r = 0.69, p < 0.001), delta of LV time to peak longitudinal deformation (r = 0.66, p < 0.001), LV global post-systolic index (r = 0.58, p < 0.001), GLSAVG (r = 0.63, p < 0.001) were established. LV DD is characterized by early diastolic longitudinal strain E of the LV basal lateral segment > −6.75%, LV basal septal segment > −5.22%, early and late diastolic longitudinal strain ratio E/A of the LV basal lateral segment ≤0.91, basal-septal segment ≤0.69. LV DD type I is characterized by an LV mechanical dispersion index >49.34 ms, LV delta time to peak longitudinal strain >157 ms. Prognostic values for LV DD type II are LV mechanical dispersion index >49.34 ms, delta time to peak longitudinal strain is >136 ms, global post-systolic index >6.24%, mechanical dyssynergy index >4.60%, global LV peak longitudinal displacement ≤9.88 mm, GLSAVG > −18.5% (sensitivity 88.2%, specificity 83.3%).
Conclusions. The use of the developed STE prediction value in practical public health will increase the efficiency of diagnosis of LV DD.
Due to intracardiac circulatory changes atrial fibrillation creates conditions for thrombus formation in the left atrial appendage (LAA). The presence of thrombus in LAA is poor prognostic factor of subsequent cardiovascular events. It is the source of up to 64% of ischemic stroke cases, and concomitant anticoagulant therapy leads to a high frequency of hemorrhagic conversion. For patient with symptomatic and drug-refractory arrhythmia is recommended surgical rhythm correction or electrical cardioversion. There is a high risk of cardioembolic stroke during the intervention, so it is necessary to exclude LAA thrombosis at pre-operation stage. The main method of LAA visualization is transesophageal echocardiography, but today computed tomography and, less, magnetic resonance tomography become important. The purpose of this review is to analyze the possibilities of each visualisation technique and their role in the diagnostic algorithm when examining patients before catheter ablation of atrial fibrillation sources.
Aim: A literature review of the possibilities of applying model iterative reconstruction (MIR) in computed tomography to improve image quality, including in low-dose scanning protocols.
Materials and methods. The analysis of publications devoted to the application of MIR to reduce the radiation dose and improve the quality of images in CT diagnostics of lung pathology with an emphasis on the value of the achieved radiation dose was carried out.
Results. The use of MIR eliminates digital noise from medical images, improving their quality. This feature can significantly reduce radiation exposure with low-dose protocols without loss of diagnostic quality. On average, application of MIR allows to reduce the radiation dose by 70% compared to a standard protocol, without increasing the noise level of CT images and maintaining the contrast-to-noise ratio. Previous studies have shown positive experience with the use of MIR in lung cancer screening programs and monitoring of cancer patients.
Conclusion. The introduction of MIR in clinical practice can optimize the radiation exposure on the population without reducing the quality of CT images, however, the threshold dose to achieve a satisfactory image quality remains unexplored.
HEAD
Aim. To evaluate the neuroimaging patterns of chronic cerebrovascular insufficiency with cerebral perfusion assessment depending on the level of cognitive impairment.
Materials and methods. The 58 patients aged 50–79 years were examined: 45 patients with a diagnosis of сhronic cerebrovascular insufficiency and 13 conditionally healthy volunteers. Patients with Chronic cerebrovascular insufficiency were ranked into three subgroups depending on the severity of cognitive impartment (CI). T1-, T2, T2*- VI, DWI, FLAIR and non-contrast MR perfusion (ASL) were included in the MR-protocol (Toshiba Vantage Titan, 1.5 T). The analysis of MRM patterns of Chronic cerebrovascular insufficiency was carried out according to STRIVE criteria. The total cerebral blood flow and regional in the frontal and parietal lobes were evaluated by the ASLperfusion.
Results. A relationship was found between the degree of leukoaraiosis, the type of expansion of the perivascular spaces of Virchow-Robin and the level of CI. According to ASL, total cerebral blood flow is higher in groups without CI and in patients with severe CI. There is a diffuse decrease of cerebral perfusion in patients with mild CI. This phenomenon is explained by initial impairment of the blood-brain barrier permeability, damage to the microvasculature. Relative hyperperfusion in the cortex of the frontal and parietal lobes of patients with dementia indicates the ineffectiveness of increased cortical blood flow and the resulting shunt blood flow due to the high resistance of the altered small cerebral vessels under high pulsating properties of the main arteries.
Conclusion. ASL perfusion is a complementary link to the STRIVE criteria in the diagnosis of chronic cerebrovascular insufficiency. The absence of changes in cerebral perfusion in patients with subjective manifestations of chronic cerebrovascular insufficiency makes it advisable to search for new methods for the diagnosis of preclinical stages of vascular cognitive impairment.
MEDICAL TECHNOLOGIES
Purpose: to consider the epidemiology and classification of errors in radiologic diagnostics.
Materials and methods. The analysis of articles devoted to elucidating the possible causes of diagnostic errors published before 2019 is carried out. A retrospective analysis of the research results revealed the most frequent cognitive biases affecting clinical decision making. Strategies have been developed to combat these distortions, which minimize the likelihood of errors.
Discussion. Image analysis by doctors is a complex work based on a combination of psychophysiological and cognitive processes, which in itself is subject to a wide variety of errors, including perception errors (when pathological changes are simply skipped) and cognitive errors (those cases when pathological changes are detected visually but incorrectly interpreted). Although some of the changes in the radiation images may be skipped due to technical or physical limitations of the modality (resolution, signal-to-noise ratio, artifacts, etc.), most diagnostic discrepancies are associated with an incorrect interpretation of the findings by radiologists.
Conclusions. Cognitive distortions can significantly affect the process of making diagnostic decisions, and lead to medical errors and negative consequences for patients. Various cognitive strategies and metacognitive practices can help minimize the impact of bias on decision making and reduce the frequency of diagnostic errors. Knowing one’s limitations and possibilities in interpreting radiation research, as well as understanding the role of the radiologist in the formation of the final diagnosis and, accordingly, in the fate of the patient, can lead to a more thoughtful analysis of images and clinical information and improve the quality of the diagnostic decision-making process.
ISSN 2408-9516 (Online)