VCBM 16: Eurographics Workshop on Visual Computing for Biology and Medicine

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https://diglib.eg.org/handle/10.2312/2630861

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Browsing VCBM 16: Eurographics Workshop on Visual Computing for Biology and Medicine by Subject "Categories and Subject Descriptors (according to ACMCCS)"

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    A Framework for Fast Initial Exploration of PC-MRI Cardiac Flow
    (The Eurographics Association, 2016) Broos, Arjan J. M.; Hoon, Niels H. L. C. de; Koning, Patrick J. H. de; Geest, Rob J. van der; Vilanova, Anna; Jalba, Andrei C.; Stefan Bruckner and Bernhard Preim and Anna Vilanova and Helwig Hauser and Anja Hennemuth and Arvid Lundervold
    Cardiac flow is still not fully understood, and is currently an active research topic. Using phase-contrast magnetic resonance imaging (PC-MRI) blood flow can be measured. For the inspection of such flow, researchers often rely on methods that require additional scans produced by different imaging modalities to provide context. This requires labor-intensive registration and often manual segmentation before any exploration of the data is performed. This work provides a framework that allows for a quick exploration of cardiac flow without the need of additional imaging and time-consuming segmentation. To achieve this, only the 4D data from one PC-MRI scan is used. A context visualization is derived automatically from the data, and provides context for the flow. Instead of relying on segmentation to deliver an accurate context, the heart's ventricles are approximated by half-ellipsoids that can be placed with minimal user interaction. Furthermore, seeding positions for flow visualization can be placed automatically in areas of interest defined by the user and based on derived flow features. The framework enables a user to do a fast initial exploration of cardiac flow, as is demonstrated by a use case and a user study involving cardiac blood flow researchers.
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    Temporal Interpolation of 4D PC-MRI Blood-flow Measurements Using Bidirectional Physics-based Fluid Simulation
    (The Eurographics Association, 2016) Hoon, Niels H. L. C. de; Jalba, Andrei C.; Eisemann, Elmar; Vilanova, Anna; Stefan Bruckner and Bernhard Preim and Anna Vilanova and Helwig Hauser and Anja Hennemuth and Arvid Lundervold
    Magnetic Resonance Imaging (MRI) enables volumetric and time-varying measurements of blood-flow data. Such data have shown potential to improve diagnosis and risk assessment of various cardiovascular diseases. Hereby, a unique way of analysing patient-specific haemodynamics becomes possible. However, these measurements are susceptible to artifacts, noise and a coarse spatio-temporal resolution. Furthermore, typical flow visualization techniques rely on interpolation. For example, using pathlines requires a high quality temporal resolution. While numerical simulations, based on mathematical flow models, address some of these limitations, the involved modelling assumptions (e.g., regarding the inflow and mesh) do not provide patientspecific data to the degree actual measurements would. To overcome this issue, data assimilation techniques can be applied to use measured data in order to steer a physically-based simulation of the flow, combining the benefits of measured data and simulation. Our work builds upon such an existing solution to increase the temporal resolution of the measured data, but achieves significantly higher fidelity. We avoid the previous damping and interpolation bias towards one of the measurements, by simulating bidrectionally (forwards and backwards through time) and using sources and sinks. Our method is evaluated and compared to the, currently-used, conventional interpolation scheme and forward-only simulation using measured and analytical flow data. It reduces artifacts, noise, and interpolation error, while being closer to laminar flow, as is expected for flow in vessels.