Background: Progression of aortic valve calcifications (AVC) leads to aortic valve stenosis (AS). Importantly, the AVC degree has a great impact on AS progression, treatment selection and outcomes. Methods of AVC assessment do not provide accurate quantitative evaluation and analysis of calcium distribution and deposition in a repetitive manner. Objective: We aim to prepare a reliable tool for detailed AVC pattern analysis with quantitative parameters. Methods: We analyzed computed tomography (CT) scans of fifty patients with severe AS using a dedicated software based on MATLAB version R2017a (MathWorks, Natick, MA, USA) and ImageJ version 1.51 (NIH, USA) with the BoneJ plugin version 1.4.2 with a self-developed algorithm. Results: We listed unique parameters describing AVC and prepared 3D AVC models with color pointed calcium layer thickness in the stenotic aortic valve. These parameters were derived from CT-images in a semi-automated and repeatable manner. They were divided into morphometric, topological and textural parameters and may yield crucial information about the anatomy of the stenotic aortic valve. Conclusion: In our study, we were able to obtain and define quantitative parameters for calcium assessment of the degenerated aortic valves. Whether the defined parameters are able to predict potential long-term outcomes after treatment, requires further investigation.

No abstract

TX 7W83-3836, and U S,A., fax 01.972-952-have been developed for this application at Shell International Exploration and Production, Research and Technical Services (SIEP-RTS).~is paper '&Scribesthe laboratory development and screening (Sealing Ability, Mechanical Characteristics, Setting Kinetics, and Adhesion) of various candidate sealants and the optimization of these characteristics for a large scale well abandonment campaign. Trial well abandonment's using the new sealing agent(s) in NAM's Schoonebeek and IJsselmondeRidderkerk Fields are discussed. AbstractLarge scale well abandonment campaigns will soon become a rnrijor cost issue for most Operators. Traditional well abandonment comprises the removal of the production tubing followed by well plugging by mechanical plugs (as primary seal), backed up by (potentially non sealing) cement plugs. The classical abandonment operation is very costly, especially in an offshore environment, since it requires the utilization of a workover or drilling rig. Significant savings could be achieved if wells could be abandoned by a Coiled Tubing operation, during which the production tubing could be left insitu. After long negotiations, a major Dutch Oil and Gas Operator (NAM, Nederlandse Aardolie Maatschappij), convinced the legislative body of the Dutch Mining Department (SodM) that non workover rig assisted abandonment operations could be equally reliable as conventional abandonment methods provided certain operational precautions were taken. This entailed the rigorous cleaning of the production tubing and production liner by solvents and hot surfactant flushes and the utilization of (rotating) jet nozzles on CTU prior to setting of the sealing plugs. Furthermore, in critical (gas prone) wells special attention had to be devoted to the plugging material itself, since it now had to fulfill the duty of the mechanical seal, as well. Inherently, it had to display much-improved sealing characteristics (gas tightness, resilience, bonding) compared to conventional cement formulations. Novel Silicone Rubber/Portland Cement plugging materials

No abstract

Background: Paravalvular leak (PVL) is one of the most common complications of transcatheter aortic valve replacement (TAVR) and affects short-and long-term outcomes. The aim of this study was to identify the computed tomography (CT) imaging biomarkers that allow PVL after TAVR to be predicted.Methods: Patients were included who had severe aortic valve stenosis, had undergone TAVR with a selfexpanding valve, and had undergone a pre-procedural CT scan. Data on baseline characteristics, procedural and long-term outcomes were collected retrospectively. We used MATLAB software with a self-developed algorithm for CT scan analysis and found parameters that quantified aortic valve calcifications (AVC) in detail.Results: Fifty patients were included. The identified CT-derived parameters included AVC size, volume, thickness and density, as well as calcium radial distribution. The volume of the largest calcium block, calcium perimeter and calcium size (assessed by Feret's diameter) showed a strong association with PVL occurrence after TAVR (P=0.012, P=0.001 and P=0.045, respectively). The prognostic model showed that a 10 mm 2 increase in the local AVC amount in each valve section was associated with a 9.8% (95% CI: 2-18%; P=0.019) increase in the risk of PVL occurrence in the corresponding area after TAVR. ROC analysis revealed that the cut-off point of the AVC area was 96.5 mm 2 in the polar coordinate system presentation. Kaplan-Meier curves showed worse PVL-free survival in patients with more than 96.5 mm 2 of calcium area (P=0.013; log-rank).Conclusions: Quantitative AVC assessment for PVL prediction may play an important role in screening before TAVR. In future, the use of quantitative AVC assessment as an imaging biomarker in TAVR candidates and the creation and extension of an online database containing quantitative AVC parameters may help to identify high PVL risk patients.