USCT data challenge 2019

Recent years have witnessed the active development of scanning systems and reconstructionalgorithms for ultrasound computed tomography (USCT) with applications to breast imagingfor early cancer detection. Despite these advances in hardware and software development,we encounter the need for reference data to develop, test and compare different imagingmethods. With the goals of encouraging scientific exchange and collaborations, providingbenchmarks of reconstruction algorithms, and standardizing USCT data formats, we havereleased open-source data sets of simulated waveforms that mimic measurements of a USCTscanning aperture using numerical breast phantoms. This is part of ongoing efforts centeredaround the USCT platform for data exchange and collaboration

X-ray Synthesis Based on Triangular Mesh Models Using GPU-Accelerated Ray Tracing for Multi-modal Breast Image Registration

For image registration of breast MRI and X-ray mammography we apply detailed biomechanical models. Synthesizing X-ray mammograms from these models is an important processing step for optimizing registration parameters and deriving images for multi-modal diagnosis. A fast computation time for creating synthetic images is essential to enable a clinically relevant application. In this paper we present a method to create synthetic X-ray attenuation images with an hardware-optimized ray tracing algorithm on recent graphics processing units’ (GPU) ray tracing (RT) cores. The ray tracing algorithm is able to calculate the attenuation of the X-rays by tracing through a triangular polygon-mesh. We use the Vulkan API, which enables access to RT cores. One frame for a triangle mesh with over 5 million triangles in the mesh and a detector resolution of 1080×1080 can be calculated and transferred to and from the GPU in about 0.76 s on NVidia RTX 2070 Super GPU. Calculation duration of an interactive application without the transfer overhead allows real time application with more than 30 frames per second (fps) even for very large polygon models. The presented method is able to calculate synthetic X-ray images in a short time and has the potential for real-time applications. Also it is the very first implementation using RT cores for this purpose. The toolbox will be available as an open source

Refraction corrected transmission imaging based on Bézier curves: first results with KIT 3D USCT

AbstractThe computational complexity of wave-based image ultrasound transmission reconstructionsis very high especially in 3D. Hence, ray-based approximations are often used. Bent rayapproaches like the fast marching method are time-consuming in comparison to the straightray approximation. The B ́ezier curve technique for refraction approximation, introduced byPerez-Liva et al., could be a compromise between computational effort and image quality. Inthis work, the method was extended to 3D and an evaluation on two 3D datasets was carriedout. The first dataset was simulated with the k-wave toolbox, with hemispherically arrangedemitters and receivers and a sound speed inhomogeneity. With a mean squared error of 9.98m/s the method produces similar results as the fast marching method (11.85 m/s). The objectsize is represented better in comparison to the straight ray method. Applied to real data ofthe KIT 3D USCT both methods performed similarly. The object size was better preservedusing bent ray methods. The B ́ezier bent ray method shows first promising results in 3D asit leads to similar results than the fast marching method

Effects of an Adolescent Asthma Education Intervention on Knowledge, Intention, Behavior, Self-Efficacy and Self-Consciousness

In this study, we evaluated the effects of an asthma education intervention, guided by social cognitive theory, on knowledge, intention, behavior, self-efficacy, and self-consciousness. The sample consisted of 87 asthmatic adolescents in six middle and/or high schools in California. A non-equivalent comparison group design, with delayed intervention in the comparison group, was utilized. We implemented a modified version of the American Lung Association’s Kickin Asthma curriculum. Self-report questionnaires assessing the key study variables were administered at baseline, at immediate postintervention, and five weeks after the intervention. There were no statistically significant differences at post-test, controlling for pre-test values, for any of the study variables between the intervention (n = 51) and comparison groups (n = 35). After collapsing across groups, however, there were statistically significant improvements following the intervention for knowledge, intention, selected behavior variables, and self-efficacy. The evaluation of this theory-based asthma education intervention demonstrates the positive impact this curriculum can have on a sample of asthmatic adolescents

BVR photometry of the resolved dwarf galaxy Ho IX

We present BVR CCD photometry down to limiting magnitude B=23.5 mag for 232 starlike objects and 11 diffuse objects in a 5.4' x 5.4' field of Ho IX. The galaxy is a gas-rich irregular dwarf galaxy possibly very close to M 81, which makes it especially interesting in the context of the evolution of satellite galaxies and the accretion of dwarf galaxies. Investigations of Ho IX were hampered by relatively large contradictions in the magnitude scale between earlier studies. With our new photometry we resolved these discrepancies. The color magnitude diagram (CMD) of Ho IX is fairly typical of a star-forming dwarf irregular, consistent with earlier results. Distance estimates from our new CMD are consistent with Ho IX being very close to M 81 and therefore being a definite member of the M 81 group, apparently in very close physical proximity to M 81.Comment: 9 pages, 8 figures, uses aa.cls, A&A in pres