bluuebunny/crossref_metadata_2025_split huggingface dataset:
An improved tracking framework for ultrasound probe localization in image-guided radiosurgery
Authors: Ipsen Svenja , Bruder Ralf , Jauer Philipp , Ernst Floris , Blanck Oliver , Schweikard Achim 
Published: December 2016

Abstract
Real-time target localization with ultrasound holds high potential for image guidance and motion compensation in radiosurgery due to its non-invasive image acquisition free from ionizing radiation. However, a two-step localization has to be performed when integrating ultrasound into the existing radiosurgery workflow. In addition to target localization inside the ultrasound volume, the probe itself has to be localized in order to transform the target position into treatment room coordinates. By adapting existing camera calibration tools, we have developed a method to extend the stereoscopic X-ray tracking system of a radiosurgery platform in order to locate objects such as marker geometries with six degrees of freedom. The calibration was performed with 0.1 mm reprojection error. By using the full area of the flat-panel detectors without pre-processing the extended software increased the tracking volume and resolution by up to 80%, substantially improving patient localization and marker detectability. Furthermore, marker-tracking showed sub-millimeter accuracy and rotational errors below 0.1°. This demonstrates that the developed extension framework can accurately localize marker geometries using an integrated X-ray system, establishing the link for the integration of real-time ultrasound image guidance into the existing system.
Learning discriminative classification models for grading anal intraepithelial neoplasia
Authors: Kainz Philipp , Mayrhofer-Reinhartshuber Michael , Sedivy Roland , Ahammer Helmut 
Published: December 2016

Abstract
Grading intraepithelial neoplasia is crucial to derive an accurate estimate of pre-cancerous stages and is currently performed by pathologists assessing histopathological images. Inter- and intra-observer variability can significantly be reduced, when reliable, quantitative image analysis is introduced into diagnostic processes. On a challenging dataset, we evaluated the potential of learning a classifier to grade anal intraepitelial neoplasia. Support vector machines were trained on images represented by fractal and statistical features. We show that pursuing a learning-based grading strategy yields highly reliable results. Compared to existing methods, the proposed method outperformed them by a significant margin.
Regularization of EIT reconstruction based on multi-scales wavelet transforms
Authors: Gong Bo , Schullcke Benjamin , Krueger-Ziolek Sabine , Moeller Knut 
Published: December 2016

Abstract
Electrical Impedance Tomography (EIT) intends to obtain the conductivity distribution of a domain from the electrical boundary conditions. This is an ill-posed inverse problem usually solved on finite element meshes. Wavelet transforms are widely used for medical image reconstruction. However, because of the irregular form of the finite element meshes, the canonical wavelet transforms is impossible to perform on meshes. In this article, we present a framework that combines multi-scales wavelet transforms and finite element meshes by viewing meshes as undirected graphs and applying spectral graph wavelet transform on the meshes.
Assessing MRI susceptibility artefact through an indicator of image distortion
Authors: Illanes Alfredo , Krug Johannes W. , Friebe Michael 
Published: December 2016

Abstract
Susceptibility artefacts in magnetic resonance imaging (MRI) caused by medical devices can result in a severe degradation of the MR image quality. The quantification of susceptibility artefacts is regulated by the ASTM standard which defines a manual method to assess the size of an artefact. This means that the estimated artefact size can be user dependent. To cope with this problem, we propose an algorithm to automatically quantify the size of such susceptibility artefacts. The algorithm is based on the analysis of a 3D surface generated from the 2D MR images. The results obtained by the automatic algorithm were compared to the manual measurements performed by study participants. The results show that the automatic and manual measurements follow the same trend. The clear advantage of the automated algorithm is the absence of the inter- and intra-observer variability. In addition, the algorithm also detects the slice containing the largest artefact which was not the case for the manual measurements.
A framework for feedback-based segmentation of 3D image stacks
Authors: Stegmaier Johannes , Peter Nico , Portl Julia , Mang Ira V. , Schröder Rasmus , Leitte Heike , Mikut Ralf , Reischl Markus 
Published: December 2016

Abstract
3D segmentation has become a widely used technique. However, automatic segmentation does not deliver high accuracy in optically dense images and manual segmentation lowers the throughput drastically. Therefore, we present a workflow for 3D segmentation being able to forecast segments based on a user-given ground truth. We provide the possibility to correct wrong forecasts and to repeatedly insert ground truth in the process. Our aim is to combine automated and manual segmentation and therefore to improve accuracy by a tunable amount of manual input.
Doppler optical coherence tomography as a promising tool for detecting fluid in the human middle ear
Authors: Kirsten Lars , Baumgärtner Simon , Erkkilä Mikael Timo , Golde Jonas , Kemper Max , Stoppe Thomas , Bornitz Matthias , Neudert Marcus , Zahnert Thomas , Koch Edmund 
Published: December 2016

Abstract
The treatment of otitis media requires classifying the effusion in the tympanic cavity for choosing appropriate therapeutic strategies. Otoscopic examination of the middle ear depends on the expertise of the physician and is often hampered in case of inflammatory alterations of the tympanic membrane. In otologic research, optical coherence tomography is an innovative non-invasive imaging technique utilized for visualizing the tympanic membrane. This ex vivo study presents the possibility of OCT and Doppler-OCT for the detection of effusions in the tympanic cavity. Structural OCT imaging allows the direct visualization of scattering fluids behind the tympanic membrane. In addition, the measurement of the reduced oscillation amplitude by means of Doppler-OCT permits the indirect detection of scattering and transparent fluids.
3D Local in vivo Environment (LivE) imaging for single cell protein analysis of bone tissue
Authors: Taylor Carly , Scheuren Ariane , Trüssel Andreas , Müller Ralph 
Published: December 2016

Abstract
The molecular processes behind pathological bone remodelling seen in diseases such as osteoporosis are unclear. However, a recently developed methodological platform known as Local in vivo Environment (LivE) imaging has been used to link cellular expression data to the local remodelling and mechanical environment in 2D sections of bone tissue. The method therefore can be used to give insight into which proteins are important for pathological bone remodelling. However, the cells within bone tissue exist as a 3D network. Therefore extension of LivE to accommodate 3D data may provide additional physiologically relevant information that is not possible to determine using 2D analysis alone. This will have implications for the further understanding of the cellular basis that underlies bone diseases such as osteoporosis. Here the LivE imaging technique is expanded to incorporate data from cells in a three dimensional manner via a serial sectioning technique. The methodological steps involved in the LivE imaging approach are defined and the optimisation steps performed are explained in detail.
Inside-Out access strategy using new trans-vascular catheter approach
Authors: Boese Axel , Foerstenberg Dirk , Wu Tong , Friebe Michael 
Published: December 2016

Abstract
Image guided minimal invasive treatment can have large benefits for patient recovery and is lowering hospitalisation costs. But an access path, minimizing patient’s risk, is needed to reach the target structure inside of the body. Beside the use of natural orifices like oral, vaginal or anal cavities, a percutaneous puncture is common to enter the body. Also an interstitial path can be selected but if the pathological structure is situated in the deep, a long accesses path is required. Thereby the risk of additional damage and affecting organ functionality is increased. A possible option to come closer to the target structure with less organ damage is by using the vascular system. Entering the vessel from an uncritical point, the vasculature can be used as “highway” to the target structures. For the treatment of these nearby structures, the vessel has to be punctured and occluded afterwards by a save procedure. We propose an Inside-Out access strategy using a new trans-vascular catheter approach.
Impact of different registration methods in MEG source analysis
Authors: Theiß Marie , Wollbrink Andreas , Wolters Carsten H. , Brinck Heinrich 
Published: December 2016

Abstract
For this study the impact of different co-registration procedures on MEG source localization of somatosensory evoked fields was evaluated. Two different co-registration procedures were used to calculate the transformation matrix which specifies how to align the MRI data to the MEG head coordinate system. In order to depict the differences, caused by the method, the Euclidian distance between the reconstructed sources was noted. It was shown that, erroneous MRI and MEG data co- registration effects source localization results. Most dipoles are located more posterior and superior when the more advanced registration procedure was applied. In conclusion the results show, that an iterative matching procedure allows an accurate knowledge of the MEG gradiometer sensor position relative to the head which is crucial to correctly reconstruct neuronal activity derived from MEG measurements.
Designing a compact MRI motion phantom
Authors: Schmiedel Max , Moeller Anita , Koch Martin A. , Mertins Alfred 
Published: December 2016

Abstract
Even today, dealing with motion artifacts in magnetic resonance imaging (MRI) is a challenging task. Image corruption due to spontaneous body motion complicates diagnosis. In this work, an MRI phantom for rigid motion is presented. It is used to generate motion-corrupted data, which can serve for evaluation of blind motion compensation algorithms. In contrast to commercially available MRI motion phantoms, the presented setup works on small animal MRI systems. Furthermore, retrospective gating is performed on the data, which can be used as a reference for novel motion compensation approaches. The motion of the signal source can be reconstructed using motor trigger signals and be utilized as the ground truth for motion estimation. The proposed setup results in motion corrected images. Moreover, the importance of preprocessing the MRI raw data, e.g. phase-drift correction, is demonstrated. The gained knowledge can be used to design an MRI phantom for elastic motion.
Cerebral cortex classification by conditional random fields applied to intraoperative thermal imaging
Authors: Hoffmann Nico , Koch Edmund , Petersohn Uwe , Kirsch Matthias , Steiner Gerald 
Published: December 2016

Abstract
Intraoperative thermal neuroimaging is a novel intraoperative imaging technique for the characterization of perfusion disorders, neural activity and other pathological changes of the brain. It bases on the correlation of (sub-)cortical metabolism and perfusion with the emitted heat of the cortical surface. In order to minimize required computational resources and prevent unwanted artefacts in subsequent data analysis workflows foreground detection is a important preprocessing technique to differentiate pixels representing the cerebral cortex from background objects. We propose an efficient classification framework that integrates characteristic dynamic thermal behaviour into this classification task to include additional discriminative features. The first stage of our framework consists of learning this representation of characteristic thermal time-frequency behaviour. This representation models latent interconnections in the time-frequency domain that cover specific, yet a priori unknown, thermal properties of the cortex. In a second stage these features are then used to classify each pixel’s state with conditional random fields. We quantitatively evaluate several approaches to learning high-level features and their impact to the overall prediction accuracy. The introduction of high-level features leads to a significant accuracy improvement compared to a baseline classifier.
Analysis of muscle fatigue conditions using time-frequency images and GLCM features
Authors: Karthick P.A. , Navaneethakrishna M. , Punitha N. , Fredo A.R. Jac , Ramakrishnan S. 
Published: December 2016

Abstract
In this work, an attempt has been made to differentiate muscle non-fatigue and fatigue conditions using sEMG signals and texture representation of the time-frequency images. The sEMG signals are recorded from the biceps brachii muscle of 25 healthy adult volunteers during dynamic fatiguing contraction. The first and last curls of these signals are considered as the non-fatigue and fatigue zones, respectively. These signals are preprocessed and the time-frequency spectrum is computed using short time fourier transform (STFT). Gray-Level Co-occurrence Matrix (GLCM) is extracted from low (15–45 Hz), medium (46–95 Hz) and high (96–150 Hz) frequency bands of the time-frequency images. Further, the features such as contrast, correlation, energy and homogeneity are calculated from the resultant matrices. The results show that the high frequency band based features are able to differentiate non-fatigue and fatigue conditions. The features such as correlation, contrast and homogeneity extracted at angles 0°, 45°, 90°, and 135° are found to be distinct with high statistical significance (p < 0.0001). Hence, this framework can be used for analysis of neuromuscular disorders.
Numerical evaluation of image parameters of ETR-1
Authors: Ahmed Shamim , Krüger Marian , Willomitzer Christian , Zakaria Golam A. 
Published: December 2016

Abstract
In this work, we developed a method to handle the image quality test-tool precisely. This test-tool is important to evaluate the quality of the medical images for pre-treatment planning phase. But the achieved images are estimated by naked eyes, which does not provide the precise result. Our main goal is to get the desired image parameters numerically. This numerical estimation overcomes the limitation of naked eye observation. Hence, it enhances the pre-treatment planning. The ETR-1 test-tool is considered here. The contrast, the low contrast details and line-pairs (lp/mm) were estimated.
Hardware dependencies of GPU-accelerated beamformer performances for microwave breast cancer detection
Authors: Salomon Christoph J. , Ley Sebastian , Helbig Marko 
Published: December 2016

Abstract
UWB microwave imaging has proven to be a promising technique for early-stage breast cancer detection. The extensive image reconstruction time can be accelerated by parallelizing the execution of the underlying beamforming algorithms. However, the efficiency of the parallelization will most likely depend on the grade of parallelism of the imaging algorithm and of the utilized hardware. This paper investigates the dependencies of two different beamforming algorithms on multiple hardware specification of several graphics boards. The parallel implementation is realized by using NVIDIA’s CUDA. Three conclusions are drawn about the behavior of the parallel implementation and how to efficiently use the accessible hardware.
Evaluation of reconstruction parameters of electrical impedance tomography on aorta detection during saline bolus injection
Authors: Thürk Florian , Waldmann Andreas D. , Wodack Karin H. , Trepte Constantin J. , Reuter Daniel , Kampusch Stefan , Kaniusas Eugenijus 
Published: December 2016

Abstract
An accurate detection of anatomical structures in electrical impedance tomography (EIT) is still at an early stage. Aorta detection in EIT is of special interest, since it would favor non-invasive assessment of hemodynamic processes in the body. Here, diverse EIT reconstruction parameters of the GREIT algorithm were systematically evaluated to detect the aorta after saline bolus injection in apnea. True aorta position and size were taken from computed tomography (CT). A comparison with CT showed that the smallest error for aorta displacement was attained for noise figure nf = 0.7, weighting radius rw = 0.15, and target size ts = 0.01. The spatial extension of the aorta was most precise for nf = 0.7, rw = 0.25, and ts = 0.07. Detection accuracy (F1-score) was highest with nf = 0.6, rw = 0.15, and ts = 0.04. This work provides algorithm-related evidence for potentially accurate aorta detection in EIT after injection of a saline bolus.
Automatic determination of lung features of CF patients in CT scans
Authors: Chaudhuri Tanusree , Gong Bo , Krueger-Ziolek Sabine , Schullcke Benjamin , Moeller Knut 
Published: December 2016

Abstract
This paper describes a prototype of an automatic system for the detection and evaluation of Cystic fibrosis features (CF) in High resolution computed tomography (HRCT) Scans. The aim of this study lies in presenting this system as a decision support tool for radiologists in future. The CF features that have been detected and evaluated are Bronchiectasis and Mucus Plugging. This system recognizes Bronchiectasis as the presence of enlarged airways in pulmonary CF-CT slices whereas, Mucus Plugging has been recognized as clusters of high attenuation pixels. The dataset of this study consists of HRCT Scans of five CF patients of varying disease stages. Mean percentages of these CF features that were computed for each intercostal space, starting from the first to the fifth, fairly accurately match the different stages of the disease.
Image analysis of self-organized multicellular patterns
Authors: Thies Christian , Khachaturyan Galina , Zemel Assaf , Kemkemer Ralf 
Published: December 2016

Abstract
Analysis of multicellular patterns is required to understand tissue organizational processes. By using a multi-scale object oriented image processing method, the spatial information of cells can be extracted automatically. Instead of manual segmentation or indirect measurements, such as general distribution of contrast or flow, the orientation and distribution of individual cells is extracted for quantitative analysis. Relevant objects are identified by feature queries and no low-level knowledge of image processing is required.
Effect of key parameters on synthesis of superparamagnetic nanoparticles (SPIONs)
Authors: Malhotra Ankit , Spieß Felix , Stegelmeier Corinna , Debbeler Christina , Lüdtke-Buzug Kerstin 
Published: December 2016

Abstract
There are various methods to synthesize superparamagnetic nanoparticles (SPIONs) useful for MPI (magnetic particle imaging) and in therapy (Hypothermia) such as co-precipitation, hydrothermal reactions etc. In this research, the focus is to analyse the effects of crucial parameters such as effect of molecular mass of dextran and temperature of the co-precipitation. These parameters play a crucial role in the inherent magnetic properties of the resulting SPIONs. The amplitude spectrum and hysteresis curve of the SPIONs is analysed with MPS (magnetic particle spectrometer). PCCS (photon cross-correlation spectroscopy) measurements are done to analyse the size distribution of hydrodynamic diameter the resulting SPIONs.
Development of a desiccant based dielectric for monitoring humidity conditions in miniaturized hermetic implantable packages
Authors: Langenmair Michael , Rudmann Linda , Ordonez Juan , Stieglitz Thomas 
Published: December 2016

Abstract
Lifetime estimation of implanted electronics in hermetic packages requires the prediction of the humidity induced lifetime. Classical approaches are limited in applications where miniaturized packages and a buffered humidity at low values are being utilized. An approach to overcome these limitations is described and investigations on suitable materials and measurement setups are presented. The findings support the usability of a Zeolite-silicone based desiccant system as a dielectric for a new type of online sensor. The future exploitation of this new sensing principle can allow the monitoring and prediction of humidity conditions inside of highly reliable miniaturized hermetic implantable packages.
Development of an artifact-free aneurysm clip
Authors: Brack Alexander , Senger Sebastian , Fischer Gerrit , Janssen Henning , Oertel Joachim , Brecher Christian 
Published: December 2016

Abstract
For the treatment of intracranial aneurysms with aneurysm clips, usually a follow-up inspection in MRI is required. To avoid any artifacts, which can make a proper diagnosis difficult, a new approach for the manufacturing of an aneurysm clip entirely made from fiber-reinforced plastics has been developed. In this paper the concept for the design of the clip, the development of a new manufacturing technology for the fiber-reinforced components as well as first results from the examination of the components in phantom MRI testing is shown.
Enhancing the regeneration of bone defects by alkalizing the peri-implant zone – anin vitroapproach
Authors: Galow Anne-Marie , Wysotzki Philipp , Baumann Werner , Gimsa Jan 
Published: December 2016

AbstractThe effects of alkaline pH on the initial adhesion of osteoblasts to titanium surfaces was analyzed by single cell force microscopy (SCFM). In the SCFM measurements, the same cells were used to compare their unspecific adhesion to uncoated titanium with their specific adhesion to collagen coated titanium. When the maximum detachment forces (MDFs) were compared at pH 7.4 and 8.0, only slight differences were found on pure titanium, while the MDFs were significantly increased at collagen coated surfaces at pH 8.0. Effects on the subsequent proliferation and gene expression were investigated in anin vitromodel system consisting of an alkalizing polyvinyl alcohol (PVA) matrix and a perforated titanium disc. The sodium hydroxide releasing matrix maintained the medium pH between pH 7.6 and pH 8.4 during the entire experiment. Under these conditions, cell counts were significantly increased with respect to the control system after 7 days in culture. These results were supported by gene expression analyses, which showed an upregulation of proliferation-controlling genes of the EGFR1 and PI3K/AKT pathways after 14 days in culture. The SCFM data were complemented by findings of an intensive regulation of genes known to be associated with focal adhesion such as Itga8 and Tnn.
Advanced wettability analysis of implant surfaces
Authors: Jennissen Herbert P. 
Published: December 2016

Abstract
New methodologies are a major driving force of scientific progress. In this case the finding that contact angles can be expressed as complex numbers offers the possibility of a much refined analysis beyond zero degrees of rough ultra-/superhydrophilic, (now called hyperhydrophilic), metal surfaces, which play a distinct role in dental and orthopedic implantology. The approaches, a short theoretical introduction and examples from medical applications are given.