Microsurgical Fenestration of Intracranial Arachnoid Cysts: Volumetric Analysis and Clinical Outcome

Introduction: There is paucity of data regarding change in arachnoid cyst (AC) volume following surgery. This study aimed at investigating the clinical outcome of ACs and applying 2 volumetric methods for determination of their volume change post microsurgical fenestration. Methods: Twenty-one ACs in 20 patients that underwent microsurgical fenestration were analyzed using 2 volumetric methods; the modified McDonald equation and the picture archiving and communication (PAC) system-based method. Patients were followed up for 23 ± 40.3 months. Results: The majority of the patients (13 or 65%) were children. Preoperative symptoms in children were mainly seizures and less commonly headache. Of the 20 patients, 12 (60%) had complete resolution of their preoperative symptoms with 8 (40.0%) showing partial improvement. Volumetric studies showed a mean reduction in AC size of 73.7% in children and 64.4% in adults using the PAC system versus 67.9% in children and 70.5% in adults using the modified McDonald equation method. There was no correlation between the percentage decrease in AC volume post surgery and degree of symptom improvement (49.2 ± 34.3% in patients with complete vs. 60.9 ± 40.3% in patients with only partial resolution of symptoms, p = 0.57). Discussion/Conclusion: Microsurgical fenestration is an effective approach for ACs with an excellent clinical outcome apparent in the complete or partial improvement of symptoms in all patients. Volumetric estimates of ACs and their change following surgery are feasible using the modified McDonald or PAC system methods. However, there is no correlation between the percentage decrease in AC volume after surgery and degree of clinical improvement.

P3374Quantification of mitral valve regurgitation volume by 2D and 3D echocardiography compared with cardiac magnetic resonance: a systematic review and meta-analysis

Background Accurate determination of mitral valve regurgitation (MVR) volume as a measure of left ventricular overload is of great clinical importance for timing of valve repair. The reliability of different echocardiographic methods for assessment of severity of MVR, particularly in severe cases, is currently unclear. Purpose We sought to shed light on this issue by means of a systematic literature review (SLR) and meta-analysis, in which we combined results of all available published studies comparing the different echocardiographic methods with cardiac magnetic resonance (CMR) as standard reference. Methods Electronic databases PubMed and Web of Science were searched for studies examining 2-dimensional (D) and 3D transthoracic and transoesophageal echocardiography (TTE and TEE), using proximal isovelocity surface area (PISA) and volumetric methods and comparing these with CMR. Estimated mean bias with limits of agreements (LoA) derived from Bland-Altman tests and correlations coefficients (R) were pooled together using a weighted inverse variance method. Results Twenty prospective studies were eligible for meta-analysis. Overall 1187 patients with primary or secondary, mild to severe MVR were included. The mean age was 59±13 years and male gender constituted 678 (57%) of patients. Meta-analysis of bias and LoA comparing all echocardiographic methods with CMR showed moderate overestimation and poor agreement with a bias and LoA of 8.24 (−3.55, 20.03) ml, and moderate correlation with R=0.74 (0.70–0.78) p<0.001, Fig 1. 3D-PISA followed by 3D-volumetric methods showed better agreement with an underestimation of −3.20 (−12.33, 5.92) ml, R=0.84 (0.78–0.89) p<0.001 and overestimation of 4.61 (−10.17, 19.39) ml, R=0.90 (0.86, 0.94) p<0.001, respectively. 2D volumetric method showed the poorest agreement with a bias and LoA of 23.56 (−4.19, 51.31) ml, and a moderate correlation with R=0.64 (0.54–0.73), p<0.001. In 172 patients with severe degree of MVR, echocardiographic techniques (2D and 3D) were able to correctly quantify regurgitation severity only in 114 (66%) of cases. Conclusions Echocardiographic methods either under- or overestimate the severity of MVR volume, however, 3D-PISA seems to be more reliable. CMR should be considered particularly in cases of severe MVR where a decision-making prior to valve surgery deems necessary. Powerful randomized studies are needed to further assess the accuracy of different echocardiographic methods in relation to CMR.

Aluminum–Alumina Composites: Part Ⅰ: Obtaining and Characterization of Powders

The process of advanced aluminum-alumina powders production for selective laser melting was studied. The economically effective method of obtaining aluminum–alumina powdery composites for further selective laser melting was comprehensively studied. The aluminum powders with 10–20 wt. % alumina content were obtained by oxidation of aluminum in water. Aluminum oxidation was carried out at ≤200 °C. The oxidized powders were further dried at 120 °C and calcined at 600 °C. Four oxidation modes with different process temperatures (120–200 °C) and pressures (0.15–1.80 MPa) were investigated. Parameters of aluminum powders oxidation to obtain composites with 10.0, 14.5, 17.4, and 20.0 wt. % alumina have been determined. The alumina content, particle morphology, and particle size distribution for the obtained aluminum–alumina powdery composites were studied by XRD, SEM, laser diffraction, and volumetric methods. According to the obtained characteristics of aluminum–alumina powdery composites, they are suitable for the SLM process.

Left ventricular assessment

This chapter will outline the relevant structure and function of the left ventricle and its common pathophysiology such as left ventricular hypertrophy, regional wall motion abnormalities, systolic and diastolic heart failure, and Takotsubo cardiomyopathy. It will describe how focused cardiac ultrasound can be used to assess left ventricular size, shape, wall thickness, and systolic function, including linear, area, and volumetric methods, and how loading conditions impact on these. It will demonstrate how to recognize common left ventricular pathophysiology, and the advanced section will introduce how tissue Doppler can be used to assess systolic and diastolic function.

The effects of the flood of October 2008 on the water quality in the M’zab valley, Algeria

With a flow estimated at 1200 m3∙s−1 and a height of 8 m downstream, the flood that occurred on October 10, 2008 spread along the M’zab River over a length of more than 180 km. Material and human damage is visible, but its effects on the quality of the waters of the alluvial layer remain unknown: this is the purpose of this paper. Samples of groundwater were taken during the period 2005–2012 in 4 oases of the valley. Physicochemical analyses were performed using molecular and flame spectroscopic methods and also volumetric methods on water samples. The results obtained were interpreted using histograms and hydrochemical diagrams, such as the Avignon software (L.H.A) (version 4, 2008). Low effect of flood on the water quality of the alluvial aquifer was manifested by concentrations of magnesium sulphate and calcium chloride. On the other hand, there is an accumulation of salts infiltrated by sewage except for the zone of Bouchen. The diagrams show that there is an improvement in water quality in this area.