Abstract
Carotid strain imaging in 3D is not possible with
conventional focused imaging, because the frame rate is too low.
Plane wave ultrasound provides sufficiently high frame rates,
albeit at
t
he cost of image quality, especially in the off
-
axis
direction due to the lack of
focusing
. Multiple techniques have
been developed to cope with the low off
-
axis
image quality
when
performing 2D (and in future 3D) motion estimation: cross
correlation with
directional beamforming (with or without RF
(coherent) compounding) and displacement compounding. This
study compares the precision of these techniques using
linear
array ultrasound data
of a pulsating
concentric homogeneous
artery
simulated using Field II
. The transducer
(
f
c
= 9 MHz,
pitch = 197.9
μ
m, 192 elements, f
s
= 180 MHz)
transmitted
plane
waves at 3 sequentially alternating
angles (0°, +
θ
,
-
θ
) at a PRF of
2 kHz. Simulations were repeated for
θ
ranging from
1° to 20°
with increments of 1°
.
D
isplacements were estimated for frame
intervals of 1/15th s, tracked, and cumulated from diastole to
systole using either displacement com
pounding, or directional
beamforming optionally enhanced b
y RF compounding.
1D
directional beamforming with RF compounding and 2D
displacement compounding with
θ
= ~20
° per
formed equally and
best with a relative
root
-
mean
-
squared error
of ~2%
with respect
to the analytical solution
.
The mean
and standard deviation
of
the estimated motion direction
for 2D displacement compounding
with
θ
= 20
°
was 0
.
03
°
+/
-
1.43
°.
Since
displacement compounding
requires no assumptions reg
arding the motion direction, this
tech
nique
seems the best option for plane wave carotid strain
imaging.
Original language | English |
---|---|
Title of host publication | Proceedings of IEEE International Ultrasonics Symposium |
Publisher | IEEE |
Publication date | 2014 |
Pages | 1814-1817 |
ISBN (Print) | 9781479970490 |
DOIs | |
Publication status | Published - 2014 |
Event | 2014 IEEE International Ultrasonics Symposium - Hilton Hotel, Chicago, United States Duration: 3 Sept 2014 → 6 Sept 2014 https://ieeexplore.ieee.org/xpl/conhome/6917616/proceeding |
Conference
Conference | 2014 IEEE International Ultrasonics Symposium |
---|---|
Location | Hilton Hotel |
Country/Territory | United States |
City | Chicago |
Period | 03/09/2014 → 06/09/2014 |
Internet address |
Keywords
- Beamsteering
- Carotid
- Compounding
- Directional beamforming
- Motion estimation
- Plane wave
- Strain imaging