For 3-D ultrasound imaging with row-column addressed
2-D arrays, the two orthogonal 1-D transmit and receive
arrays are both used for one-way focusing in the lateral and
elevation directions separately and since they are not in the same
plane, the two-way focusing is the same as one-way focusing.
However, the achievable spatial resolution and contrast of the
B-mode images in Delay and Sum (DAS) beamforming are
limited by the aperture size and by the operating frequency.
This paper, investigates Spatial Matched Filter (SMF) beamforming
on row-column addressed 2-D arrays to increase spatial
resolution. The performance is investigated on both simulated
and experimentally collected 3-D data by comparing the Point
Spread Functions (PSFs) and the phantom images obtained with
standard DAS and with SMF. Results show that the SMF beamformer
outperforms DAS in both simulated and experimental
trials and that a higher contrast resolution can be achieved by
SMF beamforming (i.e., narrower main lobe and lower side lobes).
The 6dB, 20dB and 40dB cystic resolution for a DAS simulated
PSF at (0,0,30)mm are 1.22mm, 3.54mm and 7.46mm, for SMF
beamforming they are 1.11mm, 2.33mm and 5.42mm accordingly.
For measured RF-data of an iron needle facing toward the
transducer positioned at (0,0,32.5)mm along the central axis, the
6dB, 20dB and 40dB cystic resolution for DAS beamforming are
1.99mm, 2.19mm and 4.26mm, and they are 0.8mm, 2.06mm and
4.18mm for SMF beamforming accordingly. SMF beamforming
increases the contrast resolution which turns into a better quality
of the B-mode images.
|Conference||2015 IEEE International Ultrasonics Symposium|
|Country||Taiwan, Province of China|
|Period||21/10/2015 → 24/10/2015|