Interactive virtual probing of 4D MRI blood-flow

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.

@Article { POBCGHV11a,
  author       = "Pelt, R.F.P. van and Bescos, Javier Olivan and Breeuwer, Marcel and Clough, R.E. and Groeller, Meister Eduard
                  and Haar Romeny, B.M. ter and Vilanova, Anna",
  title        = "Interactive virtual probing of 4D MRI blood-flow",
  journal      = "IEEE Transactions on Visualization and Computer Graphics",
  number       = "12",
  volume       = "17",
  pages        = "2153--2162",
  year         = "2011",
  note         = "http://dx.doi.org/10.1109/TVCG.2011.215",
  url          = "http://graphics.tudelft.nl/Publications-new/2011/POBCGHV11a"
}