Strategies for interactive exploration of 3D flow using evenly-spaced illuminated streamlines

Abstract-Insight into the dynamics of blood-flow considerably improves the understanding of the complex cardiovascular system and its pathologies. Advances in MRI technology enable acquisition of 4D blood-flow data, providing quantitative blood-flow velocities over time. The currently typical slice-by-slice analysis requires a full mental reconstruction of the unsteady blood-flow field, which is a tedious and highly challenging task, even for skilled physicians. We endeavor to alleviate this task by means of comprehensive visualization and interaction techniques. In this paper we present a framework for pre-clinical cardiovascular research, providing tools to both interactively explore the 4D blood-flow data and depict the essential blood-flow characteristics. The framework encompasses a variety of visualization styles, comprising illustrative techniques as well as improved methods from the established field of flow visualization. Each of the incorporated styles, including exploded planar reformats, flow-direction highlights, and arrow-trails, locally captures the blood-flow dynamics and may be initiated by an interactively probed vessel cross-section. Additionally, we present the results of an evaluation with domain experts, measuring the value of each of the visualization styles and related rendering parameters.

Section: Discussionmentioning

confidence: 52%

“…the line perception could be enhanced by means of shadows [19] or halo effects [7,18]. Additionally, more elaborate opacity mappings could be applied to the presented line primitives, highlighting only the curves that portray certain properties of interest [25].…”

Section: Discussionmentioning

confidence: 99%

Exploration of 4D MRI Blood Flow using Stylistic Visualization

Pelt

Bescós

Breeuwer

et al. 2010

“…A large body of work describes the generation of integral lines, and for our purpose we focus on methods that allow real-time interaction. Interactive integral lines were readily presented by Mattausch et al [19], discussing evenly-spaced streamlines. More recently, Cuntz et al [4] and Köhn et al [15] have presented integral line tracing techniques, employing capabilities of modern consumer graphics hardware.…”

Section: Related Workmentioning

confidence: 99%

Interactive Virtual Probing of 4D MRI Blood-Flow

Pelt

Bescós

Breeuwer

et al. 2011

Fig. 1. Interactive virtual probe with flow visualization approaches, enabling exploration of cardiovascular 4D MRI blood-flow data. Color in the leftmost rendition encodes the blood-flow vorticity, while color in other renditions conveys the local blood-flow speed.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.

“…The same authors also proposed a viewdependent LIC technique for surfaces [12]. Another solution to avoid visual clutter is to use focus+context methods, for example as done by Mattausch et al [18].…”

Section: Related Workmentioning

confidence: 99%

View-Dependent Streamlines for 3D Vector Fields

Marchesin

Chen

et al. 2010

Fig. 1. Sample rendering of a plume vector field dataset using our streamline selection technique. Our technique is able to depict the interesting data features in a view-dependent fashion while avoiding self-occlusion from the streamlines, and does not require any user intervention.Abstract-This paper introduces a new streamline placement and selection algorithm for 3D vector fields. Instead of considering the problem as a simple feature search in data space, we base our work on the observation that most streamline fields generate a lot of self-occlusion which prevents proper visualization. In order to avoid this issue, we approach the problem in a view-dependent fashion and dynamically determine a set of streamlines which contributes to data understanding without cluttering the view. Since our technique couples flow characteristic criteria and view-dependent streamline selection we are able achieve the best of both worlds: relevant flow description and intelligible, uncluttered pictures. We detail an efficient GPU implementation of our algorithm, show comprehensive visual results on multiple datasets and compare our method with existing flow depiction techniques. Our results show that our technique greatly improves the readability of streamline visualizations on different datasets without requiring user intervention.