Radiomic features of epicardial adipose tissue in coronary atherosclerosis

Aim. To investigate the association of the radiomic characteristics of epicardial adipose tissue (EAT) on contrast-free computed tomography (CT) of the heart with the severity of obstructive coronary lesion and myocardial ischemia.Methods. The study included 68 patients with coronary heart disease (mean age of 63.5±9.4, 45 men and 23 women), and 15 patients (mean age 30±4.8; 14 men and 1 woman) without cardiovascular disease as a control group. All the patients underwent multispiral computed coronary angiography, coronary calcium scores (CCS) determination and stress myocardial perfusion scintigraphy. Radiomic characteristics of EAT (texture analysis by gradations of gray color) were determined on non-contrast computer tomogram images of the heart using 3D-Sliser software and the SliserRadiomics module (version 4.10.2). The obtained indicators were compared between a control and under the study groups as well as between subgroups of patients divided according to the degree of obstruction of the coronary arteries, the size of the perfusion defect, and the value of the CCS.Results. The comparative analysis of radiomic indicators of EAT between patients with coronary artery disease and the control group showed the presence of statistically significant differences between them. At the same time, the correlation analysis in the study group did not reveal any correlations between the radiomic parameters and the size of the perfusion defect, CCS or degree of stenosis of the lumen of the coronary arteries.Conclusion. The textural characteristics of EAT in patients with coronary heart disease differ from those in individuals without cardiovascular pathology. At the same time, these indicators are not associated with the severity of obstructive lesions of the coronary arteries, the value of the CCS, and the size of the perfusion defect according to scintigraphy.

EXPERIMENTAL AND MATHEMATICAL JUSTIFICATION OF THE APPLICATION DIGITAL TECHNOLOGIES FOR RECORDING THE POSITION OF THE LOWER JAW DURING TOTAL PROSTHETICS USING DENTAL IMPLANTS

Subject. When prosthetics of toothless jaws are performed, the physiological position of the lower jaw must be determined before the final structures are made. In some cases, the use of temporary prostheses for several weeks may be useful to check for a new occlusion in a centric relationship. When the correct ratio is achieved, it is difficult to transfer them from the preliminary prostheses to the final ones. This article presents a case and a technique used to communicate information about the position of the lower jaw using a digital workflow. To determine the optimal position of the lower jaw, a computer tomogram of the temporomandibular joint was used to mathematically measure the correct position of the head of the lower jaw. Purpose. To describe a technique designed to transfer the inter-occlusal relations of the upper and lower jaws, using digital technologies in the prosthetics of full adentia using dental implants. Methodology. On the example of a clinical case of rehabilitation of a patient, total removal of failed teeth was performed, followed by prosthetics of complete adentia with the installation of six implants on the upper and lower jaws. After the completion of the integration period, a cone-beam computed tomography was performed with the capture of the temporomandibular joint, and a scan of plaster models with installed gum shapers was performed. The obtained data were compared in a specialized program for mathematical calculation of the optimal position of the lower jaw. This information was used to produce registration templates for the manufacture of fixed structures supported by implants in the resulting central jaw ratio. Results. A digital protocol for determining the central ratio of the jaws allowed us to transfer the information obtained in a virtual model of the temporomandibular joint to a permanent restoration based on implants. Conclusion. The approach described in this article predictably conveys information about the optimal position of the lower jaw during prosthetics and allows you to perform the final restoration on implants with optimal occlusal ratios, based on a mathematical calculation performed in specialized programs.

PERSONIFIED BIOMECHANICS OF EDENTULOUS JAW WITH RESTORATION ON THE SCHEME OF “ALL-ON-4” AND WITH PARALLEL IMPLANTS

The technology of patient-specific computer planning of the restoration process of the edentulous mandible dentition using dental implants is considered. A model of the jaw and distribution of elastic modules by its volume are reconstructed from a computer tomogram. The model is supplemented with virtual implants and a model of the prosthetic structure and is passed on to the finite element complex, where the loading and supporting conditions are specified. Biomechanical analysis and comparison of two implant placement schemes (“All-on-4” and in parallel implants) is carried out for two types of loading that model biting and chewing.

Additional clinical and instrumental laboratory markers of the main pathogenetic variants of ischemic stroke.

Atherothrombotic stroke (ATI), cardioembolic stroke (CEI) and lacunar stroke (LI) are the main pathogenetic variants of ischemic stroke and differ not only in the final mechanism of formation of the ischemic focus, but also in the systemic disorders underlying them. Material and methods. 384 patients were examined in acute ischemic stroke using standard methods. All patients were evaluated for total cardiovascular risk with the use of scales ASCORE, CHA2DS2-VASc, Essen and the scale of recurrent stroke . Results. ATI was diagnosed in 268 (70%) patients, 70 (18%) patients, 46 (12%) patients. The highest rate on the scale of relapse of stroke is typical for patients with CEI, the lowest - for patients with LI. Patients with ATI had a high score on THE ascore scale. The highest rate on the scale CHA2DS2-VASc was observed in patients with CEI, the lowest - in patients with LI. Other indicators informative for differentiation of the studied types of AI are age, gender, Smoking, congestive heart failure, lipid profile, presence and size of cerebral infarction on computer tomogram on admission, involvement of vertebrobasilar pool, hemorrhagic transformation of the lesion, the thickness of the intima - media, degree of stenosis of internal carotid arteries, stenosis of intracranial arteries, cardiac ejection fraction, time from stroke to admission to hospital, hemiplegia, neglect syndrome, speech disorder, as well as neurological deficit on the NIHSS scale. Discussion. Patients with studied pathogenetic variants of ischemic stroke differed in severity and representation of cardiovascular risk factors, clinical picture and outcome of the disease, which confirms the point of view of phenotypic independence of ATI, KEI and LEE, probably due to genetic features.

Research of Mechanical Characteristics of Bone Tissues By Means Of the Developed Automated System of Medical Appointment

The presented system of medical appointment allows building of solid-state models of bone and soft tissues on the basis of computer tomogram data. These models are able to take into account anisotropy of biomechanical properties, to carry out multiple geometrical operations on association of models of bone tissues with various combinations of fixing systems and endoprostheses, to calculate their mechanical characteristics in various physical environments, to carry out the comparative analysis of results of the calculation. The system provides biomechanical justifications of effective methods of diagnostics and treatment of the human musculoskeletal device.

Postoperative visual loss following cerebral arteriovenous malformation surgery: a case report

We report the case of a 46 year-old woman presenting with unilateral postoperative visual loss after right frontal craniotomy for resection of an arteriovenous malformation in the supine position.The intraoperative course was uneventful with maintenance of hemodynamic stability. Blood loss was 300 ml; postoperative hemoglobin was 12.4 g/dl. In the recovery room, the patient reported loss of vision in her right eye. Ophthalmologic examination revealed decreased visual acuity, color vision, and visual field. Assessment of the retina was normal, but the patient showed a relative afferent pupillary defect consistent with the clinical diagnosis of ischemic optic neuropathy. Postoperative computer tomogram showed normal perfusion of ophthalmic artery and vein, no hemorrhage or signs of cerebral ischemia or edema. The patient recovered most of her vision 3 months after surgery.Anesthesiologists should be aware that this condition may follow uncomplicated intracranial surgeries in the supine position, and should obtain prompt ophthalmologic consultation when a patient develops postoperative visual loss.