as an
arm of
attributes
has been demonstrated
the medical
Echolucent or
as
by
end-point.
heterogeneous
asymptomatic
were
cohortsl°3-1°7
There is evidence that various
ACAS.92
(for
plaques
symptom-prone
disease
for
a
and an
ofcarotid atherosclerotic
(echomorpholo-
asympto-
symptomatic
of
local variations in
characteris-
matic
more
were
because
ulcer,
cohortl°8),
stenosis,
they
probably
presence
gy,
ulcer
studies 97,109
surface
(in
harboring
deformability, pathological
pathology
and
different
and canconfer distinct
ultrasound
studies
manifest their
Other studies have
tics)
1l0, 111 ).
impact through
demonstrated
ated with
associ-
mechanisms
that ulceration is
pathogenetic
positively
of
incident stroke.
The ultra-
the
the
of neurovascular
of
Carotid
development
degrees
predictability
embolism. 109,112-111 Consider-
b.
symptoms
plaque echomorphology.
through
above,
have
all
it
tissue characteristics ofcarotid
the
would be
to im-
sonic
plaques
ing
interesting
interest over recent
embolic mechanisms in the
attracted research
years.
into
plicate
pathogenesis
been
have
classified
of neurovascular
associated with
These characteristics
symptoms
the overall distribution of
echolucent or
those
tones
the
grey
describing
(overall
heterogeneous plaques.
and those that describe
c. Carotid stenosis. Stenosis is
a
anothervari-
brightness)
of the
able
carotid
variation of the
tones
The
grey
Based on the
describing
plaque instability.
spatial
first classifi-
as either
corre-
the
of
in
carotid
the
the
stenosis,
higher
degree
plaque
image.93
can be
higher
the incidence of
asymptomatic
both in
and
stroke,
cation,
designated
symptomatic
plaques
cohorts
co-
co-
(for
&dquo;echolucent&dquo;-&dquo;anechoic&dquo;-&dquo;hypoechoic,&dquo;
asymptomatic
horts104,10S,107,1l6
dark
on ultrasound or as
to the
on ultrasound. Based on the sec-
and for
to the
sponding
plaques
symptomatic
hortS.1l7,1l8 It would be
the
to
corresponding
&dquo;echogenic&dquo;-&dquo;hyperechoic,&dquo;
interesting
implicate
produced by
development
hemodynamic compromise
bright plaques
ond
can be
as
carotid stenosis as
for the
classification,
plaques
designated
necessary
It
could be
of
to
a
uniform echo
stroke.
that both
(echolu-
constitute
of
here
&dquo;homogeneous,&dquo; corresponding
postulated
a
to
a
severe carotid stenosis and
low
GSM
or
&dquo;heterogeneous,&dquo; corresponding
pattern
nonuniformone.94
et a195 and Polaket a195
that the
cent
of the
conditions for the
Leahy
appearance
plaque) might
have shown
neous echo
independently
pattern
heteroge-
necessary
stroke attributable to carotid
because embolic material
development
was associated with
a
atheroma,
originating
higher
probably
from the
of
neurovascular events in
prevalence
ipsilateral
In
to
be more deleterious in the
could
cross-sectional studies.
an
introduce
ofthe
attempt
plaque
presence
flow
element in the echo
of carotid
of
a
low cerebral
state. Based on the above-
a
analysis
quantitative
ultrasonic
a197
the
cited
GSM
be the unstable
d. Presence
constitutes another index of
this feature is more
this
of carotid
(low
studies,
images
plaques, Gray-Weale
type
plaque
could be considered to
schemebased on
a
classification
and
et
stenosis)
type.
ulcer. Surface
tight
proposed
of
to echolucent areas
relationship
echogenic
1 =
within the
echolucent
plaques
ulceration
for
plaques (type
echogenic plaques).
of
plaque
Based onthis clas-
to
4 =
type
plaque instability,
in
various cross-sectional studies have
sification,
prevalent
symptomatic
that the relative
was
of neu-
demonstrated
frequency
in
plaques. 109,112-115
rovascular
e. Local variations in
In
symptoms
higher
plaques types
surface deformability.
hierarchical-
and
1
2
and that the
was
a
and
status
one ultrasound
asymptomatic
study
using
estimator,
Hennerici 119 showed that
in
In the
3
and
motion
and
4. 98-101
model-based
Meairs
higher
plaques types
of
El-
higher
pursuit
accuracy,
plaques
asymptomatic
et
used the
Scale
Median
had surface motion vectors of orientation and
al,lo2
Grey
Barghouty
a
feature of an echo
to those of the internal carotid
(GSM,
analysis
computer
magnitude equal
of
as an index
overall
whereas
demon-
movement.
program)
plaque
bright-
artery,
strated evidence
symptomatic plaques
ness. In one cross-sectional
showed
of
inherent
study, they
plaque
that
with
a
low GSM
were
of
A review
characteristics.
(echolucent)
plaques
with
f. Pathological
associated
neurovascular
a
relative
This
of
be-
of
the literature
the correlation
characteristics
higher
SyMptoMS.102
tween the dark ultrasonic tissue
frequency
concerning
association be-
characteristics
tween
the
and the
histopathologic
plaques
shows
presenting symptomatology
a
and neurovascular events has been
verified in
In
of studies
a
results.
series
conflicting
natural
studies of
was associated with
whereas
prospective,
history
carotid
sympto-
having
events
intraplaque hemorrhage
matic and
in
neurovascular
asymptomatic
plaques
symptom, 112,113,120-130
the
of new cerebrovascular
others it
not.114,115,131-136 These
was
development
discrepan-
800
Heusler
