Journal article · Ahead of Print article
A Vector Flow Imaging Method for Portable Ultrasound Using Synthetic Aperture Sequential Beamforming
Department of Electrical Engineering, Technical University of Denmark1
Biomedical Engineering, Department of Electrical Engineering, Technical University of Denmark2
Copenhagen University Hospital Herlev and Gentofte3
Alexandra Institute4
Center for Fast Ultrasound Imaging, Centers, Technical University of Denmark5
This paper presents a vector flow imaging method for the integration of quantitative blood flow imaging in portable ultrasound systems. The method combines directional transverse oscillation (TO) and synthetic aperture sequential beamforming to yield continuous velocity estimation in the whole imaging region.
Six focused emissions are used to create a high-resolution image (HRI), and a dual-stage beamforming approach is used to lower the data throughput between the probe and the processing unit. The transmit/receive focal points are laterally separated to obtain a TO in the HRI that allows for the velocity estimation along the lateral and axial directions using a phase-shift estimator.
The performance of the method was investigated with constant flow measurements in a flow rig system using the SARUS scanner and a 4.1-MHz linear array. A sequence was designed with interleaved B-mode and flow emissions to obtain continuous data acquisition. A parametric study was carried out to evaluate the effect of critical parameters.
The vessel was placed at depths from 20 to 40 mm, with beam-to-flow angles of 65°, 75°, and 90°. For the lateral velocities at 20 mm, a bias between -5% and -6.2% was obtained, and the standard deviation (SD) was between 6% and 9.6%. The axial bias was lower than 1% with an SD around 2%. The mean estimated angles were 66.70° ± 2.86°, 72.65° ± 2.48°, and 89.13° ± 0.79° for the three cases.
A proof-of-concept demonstration of the real-time processing and wireless transmission was tested in a commercial tablet obtaining a frame rate of 27 frames/s and a data rate of 14 MB/s. An in vivo measurement of a common carotid artery of a healthy volunteer was finally performed to show the potential of the method in a realistic setting.
The relative SD averaged over a cardiac cycle was 4.33%.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2017 |
| Pages: | 1655-1665 |
| ISSN: | 15258955 and 08853010 |
| Types: | Journal article and Ahead of Print article |
| DOI: | 10.1109/TUFFC.2017.2742599 |
| ORCIDs: | di Ianni, Tommaso , Villagómez Hoyos, Carlos Armando , Jensen, Jørgen Arendt and 0000-0002-9380-1688 |
Apertures Array signal processing Estimation Imaging Oscillators Portable ultrasound Synthetic aperture (SA) Transducers Transverse oscillation (TO) Ultrasonic imaging Vector flow imaging (VFI)
AUTOCORRELATION BLOOD-FLOW DOPPLER SYSTEM TRANSVERSE OSCILLATION VELOCIMETRY VELOCITY ESTIMATION array signal processing biomedical transducers biomedical ultrasonics blood flow measurement blood vessels continuous data acquisition continuous velocity estimation data acquisition depth 20.0 mm to 40.0 mm directional transverse oscillation dual-stage beamforming approach flow rig system haemodynamics high-resolution image image sequences medical image processing phase-shift estimator portable ultrasound systems quantitative blood flow synthetic aperture (SA) synthetic aperture sequential beamforming approach transverse oscillation (TO) vector flow imaging (VFI) vector flow imaging method
