Methodology and hardware for assessing the quantitative characteristics of pet images in the study of dynamic objects

The description of the original phantom design for assessing the quantitative characteristics of PET images in the study of dynamic objects is given. The phantom movement is controlled by the breath synchronization system, which records the phantom movement amplitude and the duration of the movement cycle. A curve was obtained that simulates human breathing, the parameters of which (amplitude and period) correspond to those obtained in the study of the chest. The values of the ecovery coefficients and contrast are obtained taking into account the sizes of the spheres, as well as the static and dynamic types of movement of phantoms. An assessment of the discrepancy between the recovery coefficients and the contrast values for the spheres installed inside the phantom in the static and dynamic states has been made. With a decrease in the diameter (respectively, and volume) of the sphere, an increase in the difference in values (between the static and dynamic positions of the phantom) of the recovery coefficient is observed. The optimal values of the recovery coefficients obtained using the QClear reconstruction algorithm have been determined. Recommendations for the use of the developed device in the study of dynamic objects are described. It is advisable to use the installation presented in this work to control the quality of the qualitative and quantitative characteristics of diagnostic images obtained both on PET/CT scanners and during studies using SPECT/CT (single-photon emission tomograph combined with a computed tomograph).

POSSIBILITIES OF COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF PNEUMONIA ASSOCIATED WITH COVID-19

Актуальность проблемы быстрой и точной диагностики пневмонии, ассоциированной с covid-19, в период присвоения коронавирусной инфекции (covid-19) статуса пандемии, безусловно бесспорна. Своевременная диагностика влияет на прогноз заболевания. Цель оценить возможности КТ при выявлении пневмонии, ассоциированной с covid-19 и уточнения стадии развития пневмонии. Материал и методы. Исследования проводились на мультиспиральном компьютерном томографе SOMATOM Difinition AS (Siemens). В исследования включены пациенты, прошедшие КТ грудной полости с 01.06.2020. по 31.08.2020. из базы Центральной Городской Клинической Больницы (ЦГКБ) г.Алматы. Результаты КТ оценивали визуальным методом. Визуальную оценку осуществляли с использованием трехплоскостной реформации изображений, что позволяло определить локализацию, контуры, протяженность измененных участков легочной ткани. Результаты. По данным проведенных обследований у большинства пациентов были выявлены признаки воспалительных изменений в легких, которые оценивались рентгенологами нашей клиники с учетом уже известных на тот момент специфических паттернов, характерных для пневмонии, ассоциированной с covid-19. По результатам КТ органов грудной клетки при дифференциальной диагностике пневмонии, ассоциированной с covid-19 от другой легочной патологии. Специфичность составила 88%. Заключение. КТ органов грудной полости является высокоспецифичным методом исследования при диагностике пневмонии, ассоциированной с covid-19. The urgency of the problem of rapid and accurate diagnosis of pneumonia associated with covid-19 during the assignment of coronavirus infection (covid-19) pandemic status is certainly indisputable. Timely diagnosis affects the prognosis of the disease. The aim is to evaluate the possibilities of CT in detecting pneumonia associated with covid-19 and to clarify the stage of development of pneumonia. Material and methods. The studies were carried out on a multispiral computed tomograph SOMATOM Difinition AS (Siemens). The study included patients who underwent CT of the thoracic cavity from 01.06.2020. to 31.08.2020. from the base of the Central City Clinical Hospital (CGKB) in Almaty. CT results were evaluated by visual method. Visual assessment was carried out using a three-plane image reformation, which made it possible to determine the localization, contours, and extent of the altered areas of lung tissue. Results. According to the conducted examinations, most patients showed signs of inflammatory changes in the lungs, which were evaluated by radiologists of our clinic taking into account the specific patterns already known at that time, characteristic of pneumonia associated with covid-19. According to the results of CT of the chest organs in the differential diagnosis of pneumonia associated with covid-19 from other pulmonary pathology. The specificity was 88%. Conclusion. CT of the thoracic cavity is a highly specific method of investigation in the diagnosis of pneumonia associated with covid-19.

EP.TU.203COVID-19 related myocarditis following laparoscopic appendicectomy

We report a 23 year-old male patient who presented to the emergency department with 2 days of central abdominal pain, with associated pyrexia, lethargy and nausea. Of note he had had COVID-19 in November 2020 which self-resolved. Examination revealed right sided abdominal and epigastric tenderness. His C-reactive protein was 302U/L but the remaining bloods unremarkable. The working diagnosis was unclear and a computed tomograph of the abdomen and pelvis arranged which revealed uncomplicated appendicitis with mesenteric lymphadenopathy. He underwent laparoscopic appendicectomy, revealing a macroscopically inflamed appendix without perforation or peritoneal contamination. Day 1 post-operatively, he deteriorated with acute hypoxia, tachypnoea and rigors. Additionally his inflammatory markers had increased. Respiratory physician advice was sought and an urgent computed tomograph pulmonary artertiogram performed, showing no pulmonary embolus but did show bilateral lower lobe consolidation and groundglass opacities in both lungs suspicious of COVID-19. Furthermore given his persistently low blood pressure, he underwent echocardiogram which revealed the presence of COVID-19 myocarditis and impaired left ventricular systolic dysfunction with an ejection fraction of 35%. He was admitted to the intensive care unit for blood pressure support and monitoring from a respiratory perspective. With such measures both his chest and cardiovascular function improved markedly and he was discharged on long-term cardioprotective medication. This highly rare long COVID-19 related complication following laparoscopic appendicectomy is highlighted for surgeons to be aware of and consider in cases of post-operative deterioration in patients with prior COVID-19 infection.

Characteristics of Porous Aluminium Materials Produced by Pressing Sodium Chloride into Their Melts

The paper deals with research related to the production of metal cellular aluminium systems, in which production is based on the application of sodium chloride particles. In this paper, the properties of porous aluminium materials that were produced by an unconventional method—by pressing salt particles into the melt of aluminium alloy—are described. The new methodology was developed and verified for the production of these materials. The main feature of this methodology is a hydraulic forming press and a simple-shaped foundry mould. For these purposes, four different groups of sodium chloride particle sizes (1 to 3, 3 to 5, 5 to 7 and 8 to 10 mm) were applied. The preferred aluminium foundry alloy (AlSi12) was used to produce the porous aluminium samples. Based upon this developed methodology, samples of porous aluminium materials were produced and analysed. Their weight and volume were monitored, their density and relative density were calculated, and their porosity was determined. In addition, the porosity of samples and continuity of their air cells were monitored as well. An industrial computed tomograph and a scanning electron microscope were applied for these purposes.

Case Report: Ascending Aortic Pseudo-Aneurysm Following Ventricular Septal Defect Repair in a 4-Year-Old Girl

Pseudo-aneurysm is a fatal disease, and the main cause of death is massive hemorrhage secondary to the rupture of the aneurysm. This case report aims to evaluate the effects of pseudo-aneurysm excision procedure on the disease. A 4-year-old girl was readmitted on the 20th day after ventricular septal defect (VSD) closure procedure with a high fever of 40°C; aortic pseudo-aneurysm was suspected based on a spherical cystic echo (82 × 76 mm) of the ascending aorta which was detected by ultrasonic cardiogram, and the diagnosis was confirmed by an aortic computed tomograph angiography (CTA) examination and intraoperative findings. Treatment included emergency pseudo-aneurysm excision procedure and antibiotic therapy. The aortic pseudo-aneurysm was surgically removed under deep hypothermia and circulatory arrest. Antibiotics were applied according to the bacterial culture results. The pseudo-aneurysm was excised successfully, and the patient achieved a good recovery. Our case suggests that the postoperative ascending aortic pseudo-aneurysm was probably due to inappropriate purse-string suture and/or local or systematic infection, so extra precautions should be taken to avoid this life-threatening complication.

Dynamics of pulmonary injury and extracorporeal methods of hemocorrection in patients with Sars-CoV-2

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.

Naegleria Fowleri Diagnosed with Hospital Autopsy in a Toddler: A Case Study

Casestudy Naegleria fowleri, an amoeba, is typically found in warm freshwater lakes, ponds, rivers and hot springs. It is responsible for causing the incredibly rare and lethal central nervous system infection called Primary Amoebic Meningoencephalitis (PAM). In the United States, 145 confirmed cases have been documented since 1962. Most cases are associated with freshwater lakes, ponds and reservoirs, while only a handful have been linked to artificial recreational venues such as pools, interactive water play-grounds, and spas. In addition to highlighting a rare amoebic disease, this case illustrates the continued importance of hospital autopsies especially given recent ruling to eliminate the autopsy requirement by the Centers for Medicare and Medicaid Services. Results An otherwise healthy toddler had upper respiratory symptoms and otitis media days after returning from an artificial recreational water venue, becoming increasingly lethargic and febrile over the next few days. At the hospital, cerebrospinal fluid (CSF) abnormalities were suggestive but not consistent with bacterial meningitis. A meningoencephalitis panel, a Computed Tomograph (CT) scan of the head, and chest-x-ray were negative for abnormalities. Appropriate antimicrobial therapy was initiated. Three days after hospital admission, his symptoms worsened including development of dysconjugate gaze and signs of cerebellitis. He became increasingly hemodynamically unstable, suffered an arrest, and passed away days later. Conclusion Since this death did not fall under the state’s statutes mandating medicolegal autopsy, a hospital- requested autopsy was performed. Cerebral edema and a light gray to light green exudate was along the inferior and lateral left temporal lobe, brain stem, and cerebellum. An exuberant lymphoplasmacytic infiltrate with scattered polymorphonuclear leukocytes expanded the meninges. Small histiocyte-like cells with distinct eccentric nuclei and granular, vacuolated cytoplasm, confirmed by Centers for Disease Control and Prevention (CDC) to be Naegleria fowleri, were best visualized in the Virchow-Robin spaces and deeper parenchyma.

Information technology for the analysis of CT perfusion in assessing the effectiveness of treatment for glioblastoma

Purpose of the study. To develop an information technology for calculating perfusion computed tomography parameters and to evaluate the effectiveness of using the proposed program in the differential diagnosis of continued glioblastoma growth and post-radiation necrosis. Materials and methods. We examined 53 patients who were treated at the Samara Clinical Oncological Dispensary. All patients underwent CT scan in perfusion mode. The results of using the program were compared with the data that were calculated on the workstation of the GE Discovery CT750 HD computed tomograph. Results. Significant differences were found in CBV and CBF perfusion indices in groups with continued growth and post-radiation necrosis, verified by biopsy. The parameters calculated using the developed program did not differ significantly from the results obtained on a standard workstation. Conclusion. The application of the developed computer program for the analysis of CT perfusion does not depend on the equipment manufacturer, works with standard DICOM data, which increases the availability of a valuable diagnostic method. The results obtained using the proposed information technology make it possible to differentiate the continued growth of glioblastoma from post-radiation necrosis.

The use of an Intraoperative Computed Tomograph with a Navigation Station for Operations on the Spine

The aim of the study: to analyze the results of using an intraoperative computed tomography scanner with a navigation station during spinal operations. Methods. The authors conducted a retrospective and prospective analysis of the results of 350 operations using the image intensifier tube, 390 operations with O arm and 11 operations with O arm and the Stealth-Station navigation station (Medtronic, USA). To the 350 patients operated on using the image intensifier, 1822 screws were implanted, on average 5.2 screws per operation. 117 (6.5%) screws were implanted incorrectly, of which a permissible or clinically insignificant malposition of the screw was noted in 90 (4.9%) patients. Incorrectly installed screws remaining in 27 (1.5%) patients required revision surgery. To 390 patients operated with O arm, 2477 screws were implanted, on average 6.3 screws during one operation. Incorrectly 33 (1.3%) screws were implanted, of which 25 screws were acceptable malposition. Invalid malposition of 8 (0.3%) screws was eliminated during the current operation. Results. Comparative studies of the total number of incorrectly implanted screws during operations using the image intensifier tube and O arm showed that they were more often observed when using the image intensifier tube (p <0.001) and there was no unacceptable malposition of the screws when performing the operation under O arm, since it was diagnosed in time during current operation and eliminated. A total of 66 screws were implanted in 11 patients operated using O arm and the Stealth-Station navigation station, an average of 6 screws during one operation. Inaccurate implantation of screws was not observed in any patient. Conclusions. O-arm with the Stealth-Station navigation station is the most modern method of controlling the correctness of spinal operations when anatomical landmarks are partially invisible - with open operations or invisible at all - with minimally invasive surgical interventions in real time.