Kamil Szostek

Creating 3D Web-Based Viewing Services for DICOM Images

This paper presents the design of Web-based medical image viewing system. It allows easy access to the selected DICOM data. The purpose of this application is to provide 3D results of computer tomography as a projection at any angle. This system contains of modules for data storing, projection creating and image file creating. In the experimental part two common web technologies (Java and ASP) were tested in terms of performance for designed system.

Numerical Calculations for Geophysics Inversion Problem Using Apache Hadoop Technology

There are considerations on the problem of time-consuming calculations in this article. This type of computational problems concerns to multiple aspects of earth sciences. Distributed computing allows to perform calculations in reasonable time. This way of processing requires a cluster architecture.

Problems of corneal endothelial image binarization

In this paper we present two methods of binarization of corneal endothelial images. The binarization is a first step of advanced image analysis. Images of corneal endothelial obtained by the specular microscopy have a poor dynamic range and they are usually non-uniformly illuminated. The binarization endothelial images is not trivial. Two binarization algorithms are proposed. The output images are presented. The quality of algorithms is discussed.

Parallelization of the seismic ray trace algorithm

This article presents the parallelization of seismic ray trace algorithm. The chosen Urdanetas algorithm is shortly described. It provides wavelength dependent smoothing and frequency dependant scattering thanks to the implementation of Lomaxs method for approximating broad-band wave propagation. It also includes Vinje et al. wavefront propagation technique that provides fairly constant density of rays. Then the parallelized algorithm is preliminarily tested on synthetic data and the results are presented and discussed.

OpenGL in Multi-User Web-Based Applications

In this article construction and potential of OpenGL multi-user web-based application are presented. The most common technologies like: .NET ASP, Java and Mono were used with specific OpenGL libraries to visualize tree-dimensional medical data. The most important conclusion of this work is that server side applications can easily take advantage of fast GPU and produce efficient results of advanced computation just like the visualization.

Predictors of Death in Contemporary Adult Patients With Eisenmenger Syndrome

Background: Eisenmenger syndrome is associated with substantial morbidity and mortality. There is no consensus, however, on mortality risk stratification. We aimed to investigate survival and predictors of death in a large, contemporary cohort of Eisenmenger syndrome patients. Methods: In a multicenter approach, we identified adults with Eisenmenger syndrome under follow-up between 2000 and 2015. We examined survival and its association with clinical, electrocardiographic, echocardiographic, and laboratory parameters. Results: We studied 1098 patients (median age, 34.4 years; range, 16.1–84.4 years; 65.1% female; 31.9% with Down syndrome). The majority had a posttricuspid defect (n=643, 58.6%), followed by patients with a complex (n=315, 28.7%) and pretricuspid lesion (n=140, 12.7%). Over a median follow-up of 3.1 years (interquartile range, 1.4–5.9), allowing for 4361.6 patient-years observation, 278 patients died and 6 underwent transplantation. Twelve parameters emerged as significant predictors of death on univariable analysis. On multivariable Cox regression analysis, only age (hazard ratio [HR], 1.41/10 years; 95% confidence interval [CI], 1.24–1.59; P<0.001), pretricuspid shunt (HR, 1.56; 95% CI, 1.02–2.39; P=0.041), oxygen saturation at rest (HR, 0.53/10%; 95% CI, 0.43–0.65; P<0.001), presence of sinus rhythm (HR, 0.53; 95% CI, 0.32–0.88; P=0.013), and presence of pericardial effusion (HR, 2.41; 95% CI, 1.59–3.66; P<0.001) remained significant predictors of death. Conclusions: There is significant premature mortality among contemporary adults with Eisenmenger syndrome. We report, herewith, a multivariable mortality risk stratification model based on 5 simple, noninvasive predictors of death in this population.

Real-time simulation of ultrasound refraction phenomena using ray-trace based wavefront construction method

Ultrasound (US) imaging is one of the most popular techniques used in clinical diagnosis, mainly due to lack of adverse effects on patients and the simplicity of US equipment. However, the characteristics of the medium cause US imaging to imprecisely reconstruct examined tissues. The artifacts are the results of wave phenomena, i.e. diffraction or refraction, and should be recognized during examination to avoid misinterpretation of an US image. Currently, US training is based on teaching materials and simulators and ultrasound simulation has become an active research area in medical computer science. Many US simulators are limited by the complexity of the wave phenomena, leading to intensive sophisticated computation that makes it difficult for systems to operate in real time. To achieve the required frame rate, the vast majority of simulators reduce the problem of wave diffraction and refraction. The following paper proposes a solution for an ultrasound simulator based on methods known in geophysics. To improve simulation quality, a wavefront construction method was adapted which takes into account the refraction phenomena. This technique uses ray tracing and velocity averaging to construct wavefronts in the simulation. Instead of a geological medium, real CT scans are applied. This approach can produce more realistic projections of pathological findings and is also capable of providing real-time simulation.

Optimal selection of numerical models for flood embankment pore pressure and temperature data

The aim of the ISMOP project is to study processes in earthen flood embankments: water filtration, pore pressure changes, and temperature changes due to varying water levels in the riverbed. Developing a system for continuous monitoring of flood embankment stability is the main goal of this project. A full-size earthen flood embankment with built-in sensors was built in Czernichow and used to conduct experiments involving the simulation of different flood waves, with parameters mostly measured at time intervals of 15 minutes. Numerical modelling—in addition to providing information about phenomena occurring in the embankment due to external factors and changes in water level—could be used to assess the state of the embankment. Modelling was performed using Itasca Flac 2D 7.0 with an assumed grid cell size of 10x10 cm. The water level in the embankment simulated the water flow in the Wisla River and the temperature of the air and water. Data about the state of the flood embankment was exported every hour. Using numerical models and real experiment data, a model-driven module was used to perform comparisons. Analyses of each half-section of the flood embankment were carried out separately using similarity measures and an aggregate window. For the tests, the North-West (NW) half cross-section of the embankment was chosen, which contains pore pressure and temperature sensors UT6 to UT10. The water level in the embankment was raised to a height of 3m; the best numerical model was considered the one that best matched the actual data recorded by the sensors during the experiment. The experiment period was from 9pm on 29/08/2016 to 9am on 03/09/2016. Seventeen numerical models of the water level rising to 2, 3, and 4 meters were compared against real experimental data from the NW half cross-section. The first step was to verify the similarity between the incoming data from the sensors. If the correlation value exceeded 0.8, the data from the sensors was averaged. The experimental data was then compared against the numerical models using least absolute deviations L1-Norm. The L1-Norm varied from 26 to 32, depending on window length and the numerical model used.

Predictors of Death in Contemporary Adult Patients With Eisenmenger SyndromeClinical Perspective

Background: Eisenmenger syndrome is associated with substantial morbidity and mortality. There is no consensus, however, on mortality risk stratification. We aimed to investigate survival and predictors of death in a large, contemporary cohort of Eisenmenger syndrome patients. Methods: In a multicenter approach, we identified adults with Eisenmenger syndrome under follow-up between 2000 and 2015. We examined survival and its association with clinical, electrocardiographic, echocardiographic, and laboratory parameters. Results: We studied 1098 patients (median age, 34.4 years; range, 16.1–84.4 years; 65.1% female; 31.9% with Down syndrome). The majority had a posttricuspid defect (n=643, 58.6%), followed by patients with a complex (n=315, 28.7%) and pretricuspid lesion (n=140, 12.7%). Over a median follow-up of 3.1 years (interquartile range, 1.4–5.9), allowing for 4361.6 patient-years observation, 278 patients died and 6 underwent transplantation. Twelve parameters emerged as significant predictors of death on univariable analysis. On multivariable Cox regression analysis, only age (hazard ratio [HR], 1.41/10 years; 95% confidence interval [CI], 1.24–1.59; P<0.001), pretricuspid shunt (HR, 1.56; 95% CI, 1.02–2.39; P=0.041), oxygen saturation at rest (HR, 0.53/10%; 95% CI, 0.43–0.65; P<0.001), presence of sinus rhythm (HR, 0.53; 95% CI, 0.32–0.88; P=0.013), and presence of pericardial effusion (HR, 2.41; 95% CI, 1.59–3.66; P<0.001) remained significant predictors of death. Conclusions: There is significant premature mortality among contemporary adults with Eisenmenger syndrome. We report, herewith, a multivariable mortality risk stratification model based on 5 simple, noninvasive predictors of death in this population.

Predictors of Death in Contemporary Adult Patients With Eisenmenger SyndromeClinical Perspective: A Multicenter Study

Background: Eisenmenger syndrome is associated with substantial morbidity and mortality. There is no consensus, however, on mortality risk stratification. We aimed to investigate survival and predictors of death in a large, contemporary cohort of Eisenmenger syndrome patients. Methods: In a multicenter approach, we identified adults with Eisenmenger syndrome under follow-up between 2000 and 2015. We examined survival and its association with clinical, electrocardiographic, echocardiographic, and laboratory parameters. Results: We studied 1098 patients (median age, 34.4 years; range, 16.1–84.4 years; 65.1% female; 31.9% with Down syndrome). The majority had a posttricuspid defect (n=643, 58.6%), followed by patients with a complex (n=315, 28.7%) and pretricuspid lesion (n=140, 12.7%). Over a median follow-up of 3.1 years (interquartile range, 1.4–5.9), allowing for 4361.6 patient-years observation, 278 patients died and 6 underwent transplantation. Twelve parameters emerged as significant predictors of death on univariable analysis. On multivariable Cox regression analysis, only age (hazard ratio [HR], 1.41/10 years; 95% confidence interval [CI], 1.24–1.59; P<0.001), pretricuspid shunt (HR, 1.56; 95% CI, 1.02–2.39; P=0.041), oxygen saturation at rest (HR, 0.53/10%; 95% CI, 0.43–0.65; P<0.001), presence of sinus rhythm (HR, 0.53; 95% CI, 0.32–0.88; P=0.013), and presence of pericardial effusion (HR, 2.41; 95% CI, 1.59–3.66; P<0.001) remained significant predictors of death. Conclusions: There is significant premature mortality among contemporary adults with Eisenmenger syndrome. We report, herewith, a multivariable mortality risk stratification model based on 5 simple, noninvasive predictors of death in this population.