Компьютерное моделирование напряженно-деформированного состояния сварных конструкций

В данной работе показано, что при оценке и обеспечении живучести сварныхметаллоконструкций важную роль играют технологические факторы. Учет их влияния реализуется на основе применения метода конечных элементов. Описана численная методика расчета остаточных сварочных напряжений и деформаций в элементах сварных металлоконструкций.Численнообосновантехнологическийметодповышенияживучестиуказанногоклассаметаллоконструкций

Assessment of Global Right Ventricular Function on 64-MDCT compared with MRI

Cédric Plumhans1, Georg Mühlenbruch1, Annuar Rapaee2, Kui-Hian Sim2, Tobias Seyfarth3, Rolf W. Günther1 and Andreas H. Mahnken

Remote control of municipal solid waste

Percutaneous image-guided interventions, such as radiofrequency ablation (RFA), biopsy, seed implantation, and several types of drainage, employ needle shaped instruments which have to be inserted into the patient's body. Precise planning of needle placement is a key to a successful intervention. The planning of the access path has to be carried out with respect to a variety of criteria for all possible trajectories to the selected target. Since the planning is performed in 2D slices, it demands considerable experience and constitutes a significant mental task. To support the process of finding a suitable path for hepatic interventions, we propose a fast automatic method that computes a list of path proposals for a given target point inside the liver with respect to multiple criteria that affect safety and practicability. Prerequisites include segmentation masks of the liver, of all relevant risk structures and, depending on the kind of procedure, of the tumor. The path proposals are computed based on a weighted combination of cylindrical projections. Each projection represents one path criterion and is generated using the graphics hardware of the workstation. The list of path proposals is generated in less than one second. Hence, updates of the proposals upon changes of the target point and other relevant input parameters can be carried out interactively. The results of a preliminary evaluation indicate that the proposed paths are comparable to those chosen by experienced radiologists and therefore are suited to support planning in the clinical environment. Our implementation focuses on RFA and biopsy in the liver but may be adapted to other types of interventions

Characterization of myocardial viability using MR and CT imaging

Cardiovascular magnetic resonance (MR) imaging is of proven clinical value for the noninvasive characterization of myocardial viability. Computed tomography (CT) is also being exploited for this indication. Examples of each of these imaging strategies for the assessment of myocardial viability will be provided in this review. Key MRI concepts and practical considerations such as customized MR imaging techniques and tailored imaging protocols dedicated to viability assessment are outlined with the primary focus on recent developments. Clinical applications of MR-based viability assessment are reviewed, ranging from rapid functional cine imaging to tissue characterization using T2-weighted imaging and T1-weighted late-contrast-enhanced imaging. Next, the merits and limitations of state-of-the-art CT imaging are surveyed, and their implications for viability assessment are considered. The final emphasis is on current trends and future directions in noninvasive viability assessment using MRI and CT

Dual-Source-CT coronary angiography for predicting success of revascularization in chronic total occlusions

Objective. 25 consecutive patients underwent cardiac CT between November 2009 and September 2012 to evaluate configuration of chronic total occlusion (CTO) of a coronary artery to assess eligibility of percutaneous recanalization. Material and methods. Between 11/2009 and 06/2014 25 consecutive patients underwent DSCT-CA for evaluation of CTO. Technical success and complication rate of revascularization procedures were documented. For image analysis the datasets of 12 parameters were used to calculate CTO-try score. By calibration to the study cohort the AC-CTO-try and simplified CTO-try score were constructed respectively and compared to J-CTO by the area under the ROC-curve. Results. 88% of CTOs involved the right coronary artery (RCA) with a mean length of 4.6 ± 2.7 cm. 68% (17/25) were stratified as difficult or very difficult CTO-segments by J-CTO. Based on CTO-try an intervention was recommended in 9/25 patients, while revascularization was attempted in 16/25 (64%) patients with a success rate of 56% (n = 9/16). Negative predictive value for revascularization failure was 75%. By using sCTOtry, discrimination between success and failure of the intervention was measured with an AROC = 0.892. Conclusions. DSCT-CA permits visualization of the occluded vessel segment and provides a tool for assessing the probability of revascularization failure based on the CTO-try score. SCTOtry, calibrated to our cohort and expertise, can be used for predicting success of recanalization attempt

CIRSE Clinical Practice Manual

Background Interventional radiology (IR) has come a long way to a nowadays UEMS-CESMA endorsed clinical specialty. Over the last decades IR became an essential part of modern medicine, delivering minimally invasive patient-focused care. Purpose To provide principles for delivering high quality of care in IR. Methods Systematic description of clinical skills, principles of practice, organizational standards and infrastructure needed for the provision of professional IR services. Results There are IR procedures for almost all body parts and organs, covering a broad range of medical conditions. In many cases IR procedures are the mainstay of therapy, e.g. in the treatment of hepatocellular carcinoma. In parallel the specialty moved from the delivery of a procedure towards taking care for a patient's condition with the interventional radiologists taking ultimate responsibility for the patient's outcomes. Conclusions The evolution from a technical specialty to a clinical specialty goes along with changing demands on how clinical care in IR is provided. The CIRSE Clinical Practice Manual provides interventional radiologist with a starting point for developing his or her IR practice as a clinician