<s>
Carotid	B-Algorithm
ultrasonography	I-Algorithm
is	O
an	O
ultrasound-based	O
diagnostic	O
imaging	O
technique	O
to	O
evaluate	O
structural	O
details	O
of	O
the	O
carotid	O
arteries	O
.	O
</s>
<s>
Carotid	O
ultrasound	B-Application
is	O
used	O
to	O
diagnose	O
carotid	O
artery	O
stenosis	O
(	O
CAS	O
)	O
and	O
can	O
assess	O
atherosclerotic	O
plaque	O
morphology	O
and	O
characteristics	O
.	O
</s>
<s>
Carotid	B-Algorithm
duplex	I-Algorithm
and	O
contrast-enhanced	O
ultrasound	B-Application
are	O
two	O
of	O
the	O
most	O
common	O
imaging	O
techniques	O
used	O
to	O
evaluate	O
carotid	O
artery	O
disease	O
.	O
</s>
<s>
Carotid	O
ultrasound	B-Application
is	O
a	O
low-cost	O
,	O
noninvasive	O
,	O
and	O
accurate	O
diagnostic	O
imaging	O
modality	O
used	O
to	O
evaluate	O
diseases	O
of	O
the	O
carotid	O
arteries	O
.	O
</s>
<s>
Carotid	O
ultrasound	B-Application
is	O
the	O
preferred	O
initial	O
diagnostic	O
test	O
to	O
evaluate	O
carotid	O
artery	O
stenosis	O
,	O
and	O
can	O
also	O
be	O
used	O
to	O
monitor	O
response	O
to	O
lipid-lowering	O
therapy	O
.	O
</s>
<s>
Digital	O
subtraction	O
angiography	O
(	O
DSA	O
)	O
,	O
magnetic	B-Algorithm
resonance	I-Algorithm
angiography	I-Algorithm
(	O
MRA	O
)	O
,	O
and	O
CT	O
angiography	O
(	O
CTA	O
)	O
are	O
confirmatory	O
imaging	O
techniques	O
typically	O
employed	O
after	O
ultrasound	B-Application
and	O
prior	O
to	O
therapeutic	O
intervention	O
.	O
</s>
<s>
DSA	O
is	O
the	O
gold	O
standard	O
for	O
evaluating	O
CAS	O
,	O
and	O
MRI	B-Algorithm
is	O
the	O
gold	O
standard	O
for	O
carotid	O
plaque	O
imaging	O
.	O
</s>
<s>
Duplex	B-Algorithm
ultrasound	I-Algorithm
(	O
duplex	O
)	O
combines	O
standard	O
B-mode	O
ultrasound	B-Application
and	O
Doppler	B-Algorithm
ultrasonography	I-Algorithm
to	O
evaluate	O
both	O
structural	O
details	O
of	O
the	O
carotid	O
arteries	O
and	O
blood	O
flow	O
through	O
the	O
arteries	O
.	O
</s>
<s>
During	O
carotid	B-Algorithm
duplex	I-Algorithm
evaluation	O
,	O
the	O
2D	O
B-mode	O
structural	O
image	O
is	O
superimposed	O
with	O
the	O
doppler	O
flow	O
data	O
,	O
which	O
provides	O
a	O
more	O
realistic	O
anatomical	O
assessment	O
.	O
</s>
<s>
B-mode	O
ultrasound	B-Application
is	O
able	O
to	O
assess	O
the	O
structure	O
of	O
the	O
carotid	O
arteries	O
and	O
can	O
identify	O
areas	O
of	O
stenosis	O
.	O
</s>
<s>
B-mode	O
is	O
used	O
identify	O
stenotic	O
lesions	O
and	O
to	O
assess	O
the	O
echogenicity	O
of	O
plaques	O
—	O
strong	O
correlation	O
has	O
been	O
established	O
between	O
sonographic	B-Application
and	O
histopathologic	O
features	O
of	O
plaques	O
.	O
</s>
<s>
Plaque	O
echolucency	O
can	O
signal	O
an	O
at-risk	O
plaque	O
,	O
as	O
it	O
is	O
the	O
sonographic	B-Application
equivalent	O
of	O
a	O
LNRC	O
.	O
</s>
<s>
Doppler	B-Algorithm
ultrasound	I-Algorithm
allows	O
for	O
assessment	O
of	O
carotid	O
arterial	O
blood	O
flow	O
.	O
</s>
<s>
Therefore	O
,	O
doppler	O
imaging	O
substantially	O
aids	O
in	O
the	O
diagnosis	O
of	O
carotid	O
artery	O
stenosis	O
by	O
ultrasound	B-Application
.	O
</s>
<s>
Contrast-enhanced	O
ultrasound	B-Application
(	O
CEUS	O
)	O
is	O
valuable	O
because	O
the	O
contrast	O
does	O
not	O
diffuse	O
into	O
surrounding	O
tissues	O
,	O
and	O
therefore	O
all	O
signals	O
are	O
intravascular	O
.	O
</s>
<s>
Plaque	O
enhancement	O
on	O
ultrasound	B-Application
has	O
been	O
proven	O
to	O
correlate	O
with	O
neovascularization	O
,	O
inflammation	O
,	O
and	O
inflammation	O
,	O
and	O
these	O
features	O
are	O
associated	O
with	O
symptomatic	O
carotid	O
plaques	O
.	O
</s>
<s>
Intravenous	O
contrast	O
is	O
able	O
to	O
improve	O
the	O
performance	O
of	O
carotid	O
ultrasound	B-Application
in	O
diagnosing	O
carotid	O
artery	O
stenosis	O
.	O
</s>
<s>
Contraindications	O
to	O
the	O
ultrasound	B-Application
contrast	O
include	O
allergy	O
,	O
heart	O
failure	O
,	O
acute	O
coronary	O
syndrome	O
,	O
endocarditis	O
,	O
ventricular	O
arrhythmia	O
,	O
and	O
unstable	O
respiration	O
.	O
</s>
<s>
While	O
ultrasound	B-Application
is	O
able	O
to	O
assess	O
plaque	O
morphology	O
,	O
it	O
is	O
limited	O
in	O
both	O
specificity	O
and	O
sensitivity	O
in	O
assessing	O
lipid-rich	O
necrotic	O
core	O
,	O
plaque	O
hemorrhage	O
,	O
and	O
ulceration	O
when	O
compared	O
to	O
the	O
gold	O
standard	O
.	O
</s>
<s>
When	O
diagnosing	O
carotid	O
artery	O
stenosis	O
,	O
carotid	O
ultrasound	B-Application
has	O
a	O
lower	O
sensitivity	O
than	O
MRA	O
but	O
is	O
more	O
sensitive	O
than	O
CTA	O
.	O
</s>
<s>
A	O
major	O
limitation	O
of	O
carotid	O
ultrasound	B-Application
is	O
a	O
high	O
degree	O
of	O
inter-/intraobserver	O
variability	O
;	O
however	O
,	O
computerized	O
algorithms	O
used	O
for	O
evaluation	O
of	O
the	O
intima-media	O
thickness	O
(	O
IMT	O
)	O
,	O
a	O
measure	O
of	O
plaque	O
morphology	O
,	O
have	O
helped	O
minimize	O
the	O
degree	O
of	O
variability	O
.	O
</s>
<s>
Carotid	O
ultrasound	B-Application
is	O
dependent	O
on	O
operator	O
skill	O
,	O
and	O
other	O
noted	O
areas	O
of	O
limitation	O
are	O
poor	O
insonation	O
angle	O
,	O
poor	O
blood	O
flow	O
,	O
and	O
deep	O
artery	O
location	O
.	O
</s>
