1. Illustrative Flow Visualization from 3D Doppler Ultrasound Åsmund Birkeland 1, Linn Heljesen 1,2, Kim Nylund 2, Dag Magne Ulvang 3, Odd Helge Gilja 1,2 and Ivan Viola 1,3 University of Bergen (1) Haukeland University Hospital (2) Christian Michelsen Research (3)

2. Motivation What we want: 3D Blood flow measurement Live Inexpensive Non-invasive What we have: 4D MRI – expensive, not live B-flow – only in 2D CEUS – invasive Doppler -... 2/21

3. Motivation Pros: Inexpensive Live Non-invasive Spatial in 3D Cons: Noisy Single component of the blood flow Difficult to interpret for laymen 3/21

4. Methodology 4/21

5. Geometry Extraction Segmentation Vessels extend beyond the sector of a single 3D ultrasound cone Image based registration for fusing segments from several cones Vessel geometry Extract center-line of segmented vessels Generate a vessel-direction map based on nearest center-line point 5/21

6. 3D Flow Reconstruction Probe position tracked using image based registration Reconstruction: Flux through a cross section: 6/21

7. Results Verification based on 4D MRI data Accuracy 69% for angles above 55 degrees 7/21

8. Results 8/21

9. Future Directions In-situ evaluation Improve visual representation More advanced flow model 9/21

10. Thank you for listening Questions? 10/21