Center for Fast Ultrasound ImagingDepartment of Electrical Engineering

Using Phased Array for Transverse OscillationVector Velocity Imaging

Michael Johannes Pihl1, Per Haugaard2, and Jørgen Arendt Jensen1

1 Center for Fast Ultrasound Imaging, Building 349

Department of Electrical Engineering Technical University of Denmark

2 Bk Medical, Mileparken 34, 2730 Herlev Denmark

EUROSON 2010Copenhagen, August 22nd-25th, 2010

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Recap from previous talks

•Vector velocity imaging

•Shallow depths (< 3-4 cm)

QUESTIONS:

Can we get further down?

Can we scan the heart?

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Outline

•Simple principle

•TO setup for phased array

•Simulation setup

•Simulation results

•Conclusion

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Principle of transverse oscillation (TO)

Axial direction Transverse direction

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Principle of transverse oscillation (TO)

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

TO beamforming

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Phased array setupPhased array

Imagearea

TOlines

•2 TO lines

–Fixed angle

–>Spacing increases

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Simulation tool

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Simulation setup

Transducer (Phased array)Elements 128Pitch 0.220 mmCenter freq. 3.5 MHz

SystemPulse rep. freq. 5 kHzNo. shots per est. 64

BloodAngle 90 degreesSpeed 1 m/sRadius 5 mm

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Simulation results

•10 cm

Relative bias: 2.6%Relative std: 6.5%

20 realizations

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Simulation results

•15 cm

Relative bias: 4.2%Relative std: 8.5%

20 realizations

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Conclusion and perspectives

•In simulation: Measure velocities at to 10-15 cm

•Potential for getting that far down in clinical in-vivo measurements

•Clinical perspectives

– Insufficient heart valves

–AAAs

•Further development

–Through simulations

–Through measurements

–3D vector velocity imaging

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Acknowledgements

This work was supported by the Advanced Technology Foundation and B-K Medical Aps.

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Thank you for your attention

Questions?

Center for Fast Ultrasound Imaging, Department of Electrical Engineering Technical University of Denmark

Clinical potential

•Vector velocity imaging

– Insufficient valves (in the heart)

–Abdominal aortic aneurisms

–Portal vein

–Renal artery

•Multigating

–Velocity and angle at every pixel

•Develop new quantitative measures