@article{Groeller_2011_IVP, title = "Interactive Virtual Probing of 4D MRI Blood-Flow", author = "Roy van Pelt and Javier Oliv\'{a}n Besc\'{o}s and Marcel Breeuwer and R.E. Clough and Eduard Gr\"{o}ller and Bart ter Haar Romeny and Anna Vilanova i Bartroli", year = "2011", abstract = "Better understanding of hemodynamics conceivably leads to improved diagnosis and prognosis of cardiovascular diseases. Therefore, an elaborate analysis of the blood-flow in heart and thoracic arteries is essential. Contemporary MRI techniques enable acquisition of quantitative time-resolved flow information, resulting in 4D velocity fields that capture the blood-flow behavior. Visual exploration of these fields provides comprehensive insight into the unsteady blood-flow behavior, and precedes a quantitative analysis of additional blood-flow parameters. The complete inspection requires accurate segmentation of anatomical structures, encompassing a time-consuming and hard-to-automate process, especially for malformed morphologies. We present a way to avoid the laborious segmentation process in case of qualitative inspection, by introducing an interactive virtual probe. This probe is positioned semi-automatically within the blood-flow field, and serves as a navigational object for visual exploration. The difficult task of determining position and orientation along the view-direction is automated by a fitting approach, aligning the probe with the orientations of the velocity field. The aligned probe provides an interactive seeding basis for various flow visualization approaches. We demonstrate illustration-inspired particles, integral lines and integral surfaces, conveying distinct characteristics of the unsteady blood-flow. Lastly, we present the results of an evaluation with domain experts, valuing the practical use of our probe and flow visualization techniques.", month = dec, issn = "1077 - 2626", journal = "IEEE Transactions on Visualization and Computer Graphics", number = "12", volume = "17", pages = "2153--2162", URL = "https://www.cg.tuwien.ac.at/research/publications/2011/Groeller_2011_IVP/", } @misc{Groeller_2011_IPV, title = "Illustrative Particle Visualization of 4D MRI Blood-Flow Data", author = "Roy van Pelt and Eduard Gr\"{o}ller and Bart ter Haar Romenij and Anna Vilanova i Bartroli", year = "2011", month = may, location = "Bergen, Norway", event = "EuroVis 2011", booktitle = "Biomedical Image Analysis", Conference date = "Poster presented at EuroVis 2011 (2011-05-31--2011-06-03)", URL = "https://www.cg.tuwien.ac.at/research/publications/2011/Groeller_2011_IPV/", }