Acute Ischemic Stroke : Infarct Core Estimation On Ct Angiography Source Images Depends On Ct Angiography Protocol Page 10

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NEURORADIOLOGY:
Infarct Core Estimation on CT Angiography Source Images Depends on Protocol
Pulli et al
and DW imaging in the protocol 2 co-
viability threshold ( 46,47 ), and cere-
Signifi cant overestimation occurs with
hort, but this was not an independent
bral metabolic rate of oxygen (CMRO
)
shortened time from contrast material
2
predictor of lesion overestimation. Be-
below the viability threshold ( 48 ). How-
injection to imaging of the ischemic ter-
cause DW imaging volumes were smaller
ever, because of the possibility of spon-
ritory and with atrial fi brillation.
in group 2 despite group 1 and group 2
taneous reperfusion in acute ischemic
Disclosures of Potential Confl icts of Interest:
having similar NIHSSSs, we cannot ex-
stroke, CMRO
better differentiates be-
2
B.P. No potential confl icts of interest to disclose.
clude DW imaging infarct underestima-
tween irreversible and reversible neu-
P.W.S. No potential confl icts of interest to dis-
tion in this group. However, given the
ronal damage than CBF ( 49,50 ). Spon-
close. R.H. No potential confl icts of interest to
minimal variations in DW imaging pro-
taneous reperfusion also challenges the
disclose. Z.A.C. No potential confl icts of interest
to disclose. M.H.L. Financial activities related
tocol and the use of the same MR im-
use of MR imaging– or CT-measured
to the present article: received research support
aging unit throughout the study period,
CBV as an alternative to estimating the
from GE Healthcare and consulting fees or hon-
this possibility seems unlikely. An alter-
infarct core at DW imaging. With rep-
oraria from CoAxia, Millennium Pharmaceuticals ,
native explanation for the difference in
erfusion of the core, CBV may be nor-
and GE Healthcare. Financial activities not related
to the present article: none to disclose. Other
DW imaging infarct size is that despite
mal despite the presence of irreversibly
relationships: none to disclose. J.A.H. Financial
similar NIHSSSs in the two groups, pa-
damaged tissue ( 51 ). Moreover, lesion
activities related to the present article: none to
tients in group 2 had better collateral
volume at acute DW imaging correlates
disclose. Financial activities not related to the
vessels. It has been shown that with
highly with that at fl umazenil positron
present article: has served as a consultant for
CareFusion, Atrius, and Phillips; receives royalties
proximal occlusions, the strength of the
emission tomography ( 52 ), a marker
from CareFusion; holds stock or stock options
collateral vessels is inversely correlated
for neuronal integrity ( 53 ), and is sim-
in IntraTech and N Focus. Other relationships:
with the size of the infarct core ( 23,34 ).
ilar to fi nal infarct volume in patients
none to disclose. R.G.G. No potential confl icts
of interest to disclose. A.J.Y. Financial activities
However, if the collateral vessels were
with successful recanalization but not
related to the present article: none to disclose.
indeed better in patients in group 2,
in patients with persistent occlusion
Financial activities not related to the present ar-
this difference would be unlikely to ex-
( 12,54 ). Despite these limitations, DW
ticle: has a grant or a grant pending with Penum-
plain the signifi cant overestimation on
imaging is widely regarded as the best
bra. Other relationships: none to disclose.
CT angiography source images of the
imaging modality for estimating the in-
DW imaging infarct volume seen in
farct core in the acute setting.
References
these patients. On the contrary, better
Finally, we cannot exclude that rep-
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lateral circulation (eg, timing and ex-
sions that were identifi able at CT an-
the American Heart Association . Stroke
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for assessment of the infarct core. It
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Therapeutics and Technology Assessment
intense regions at DW imaging can
window of 9 hours was chosen because
Subcommittee of the American Academy of
reverse themselves ( 35–38 ), but re-
it is the longest time after stroke where
Neurology . Neurology 2010 ; 75 ( 2 ): 177 – 185 .
cently ( 39 ) this was shown to be a rare
there is clinical evidence to support a
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Desmoteplase in Acute Ischemic Stroke
versal when tissue shrinkage was taken
who are selected on the basis of imag-
Trial (DIAS): a phase II MRI-based 9-hour
into account. Moreover, such reversal
ing fi ndings ( 4,5 ).
window acute stroke thrombolysis trial with
at DW imaging does not improve clin-
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ical outcome ( 37,40 ), and delayed re-
col changes designed to speed imaging
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associated with signifi cant overestima-
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mic Stroke (DEDAS): evidence of safety
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and effi cacy 3 to 9 hours after stroke onset .
Stroke 2006 ; 37 ( 5 ): 1227 – 1231 .
been shown to represent several path-
concurrent DW imaging, which may
ophysiologic processes ( 43,44 ), such
lead to inappropriate exclusion of pa-
6 . Wintermark M , Meuli R , Browaeys P , et al .
as tissue acidosis ( 45 ), CBF above the
tients who may benefi t from treatment.
Comparison of CT perfusion and angiography
602
Radiology: Volume 262: Number 2—February 2012
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