G. W. Kuster et al. / Case Reports in Clinical Medicine 2 (2013) 470-472 471
ABCD2 score. The only remarkable finding was a
proximal moderate left internal carotid stenosis (50%)
detected by the carotid ultrasound examination. He was
discharged and referred to the neurological outpatient
clinic with an optimized medical therapy.
Four mouth later, he presented a recurrence of similar
symptoms without a complete recovery (NIHSS = 2) and
arrived at hospital outside of the therapeutic window for
reperfusion. Brain MRI demonstrated an ischemic stroke
lesion in the corona radiata and frontal cortex visible in
the FLAIR and T2-weighted imaging. Carotid angio-
graphy showed a 60% stenosis in the left proximal
internal carotid artery with a regular surface (Figure
1(A)). CT plaque imaging (Figure 1(B)) detected a thin
fibrous cap with calcification and an intraplaque hemorr-
hage (Figure 1(C)) classified as a high-risk plaque ac-
cording to the American Heart Association plaque
classification [7]. These findings were confirmed in the
histolopathological study of the atherosclerotic plaque
(Figure 1(D)) performed after the endarterectomy. After
1 year of follow-up, the patien t returned indep enden tly to
his daily activities (modified Rankin score = 1).
3. DISCUSSION
Carotid ultrasound is usually the first line exa mination
to evaluate carotid disease in patients with TIA and
Figure 1. (A) Digital Subtraction Angiography with 60% bulb
carotid stenosis, according NASCET criteria, and regular
surface (arrow). (B,C) Contrast CT carotid plaque imaging with
a thin fibrous cap (green), calcification (blue), rich lipid ne-
crotic core (yellow) and intraplaque hemorrhage (red). (D)
Histological sample (HE, ×400) of pos endarterectomy carotid
plaque confirming hemorrhage (arrow).
detects a stenosis degree in the lower limit of the range
(50%) for a clinical decision in favor of carotid endarte-
rectomy in our patients.
Carotid angiography performed in the recurrent
ischemic event did not significantly add new information.
We hypothesized that the stenosis grade obtained (60%)
might have changed during the interval between the two
ischemic events due to dynamic modification in the
structure and have turned into a high risk plaque. CT
plaque imaging identified features beyond luminal ste-
nosis or plaque surface and represented a new non-
invasive imaging technique that might reliably assess
plaque vulnerability in symptomatic carotid disease pa-
tients presenting with an acute ischemic event. Based on
histological American Heart Association criteria, the
classification allows categorization of carotid plaques
noninvasively into distinct lesion types (I-VIII). Athero-
sclerotic plaques that are prone to rupture owing to their
intrinsic composition such as a large lipid core, thin
fibrous cap and intraplaque hemorrhage are associated
with subsequent thromboembolic ischemic events as oc-
curred in our patients.
CT plaque imaging classification worked less well for
classifying lipid-rich necrotic cores and hemorrhage,
probably because the range of densities associated with
these components overlapped with the densities as-
sociated with connective tissue, but they showed a good
correlation with histological classification when only
large lipid core and large hemorrhage are considered [5].
On the other hand, MRI has also some limitations in the
acute stroke evaluation and needs a specific phased-array
surface coil for plaque examination [6].
Timing of carotid endarterectomy after an ischemic
event may largely influence outcome. Therefore, we
propose the inclusion of noninvasive CT plaque imaging
in the evaluation of acute TIA with moderate carotid
stenosis to better select patients with high er risk of strok e
recurrence.
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