Characterization of blood-flow patterns from phase-contrast MRI velocity fields

Hemodynamic information has proven valuable for analysis of cardiovascular diseases. Aberrant blood-flow patterns, for instance, often relate to disease progression. Magnetic resonance imaging enables blood-flow measurements that provide three-dimensional velocity fields during one heartbeat. However, visual analysis of these data is challenging, because of the abundance and complexity of information. Explicit feature extraction can facilitate the pattern characterization, and hence support visualization techniques to effectively convey anomalous flow areas. In this work, we improve on existing pattern matching methods that characterize blood-flow patterns in volumetric imaging data. To this end, we propose a set of helical and vortical patterns that can be parameterized by a single variable. The characterization performance is validated on both synthetic and imaging blood-flow data. Moreover, we present a comprehensive visualization based on the pattern matching results, enabling semi-quantitative assessment of the patterns in relation to the cardiovascular anatomy.