9
Î The usefulness of chest radiographs in the hyperacute stroke setting
in the absence of evidence of acute pulmonary, cardiac, or pulmonary
vascular disease is unclear. If obtained, they should not unnecessarily
delay administration of fibrinolysis (IIb-B).
Early Diagnosis: Brain and Vascular Imaging
For patients with acute cerebral ischemic symptoms that have
not yet resolved:
Î Emergency imaging of the brain is recommended before initiating any
specific treatment for acute stroke (I-A). (Unchanged from 2013 guideline)
Notes: In most instances, non–contrast-enhanced CT will provide the necessary
information to make decisions about emergency management.
Î If endovascular therapy is contemplated, a noninvasive intracranial
vascular study is strongly recommended during the initial imaging
evaluation of the acute stroke patient but should not delay IV rtPA if
indicated. For patients who qualify for IV rtPA according to guidelines
from professional medical societies, initiating IV rtPA before non-
invasive vascular imaging is recommended for patients who have
not had non-invasive vascular imaging as part of their initial imaging
assessment for stroke. Non-invasive intracranial vascular imaging
should then be obtained as quickly as possible (I-A).
(New recommendation)
Î The benefits of additional imaging beyond CT and CTA or MR and MRA,
such as CT perfusion or diffusion- and perfusion-weighted imaging, for
selecting patients for endovascular therapy are unknown (IIb-C).
(New recommendation)
Note: Further randomized, controlled trials may be helpful to determine whether
advanced imaging paradigms employing CT perfusion, CTA, and MRI perfusion
and diffusion imaging, including measures of infarct core, collateral flow status,
and penumbra, are beneficial for selecting patients for acute reperfusion therapy
who are within 6 hours of symptom onset and have an ASPECTS score <6. Further
randomized, controlled trials should be done to determine whether advanced
imaging paradigms employing CT perfusion and MRI perfusion, CTA, and diffusion
imaging, including measures of infarct core, collateral flow status, and penumbra, are
beneficial for selecting patients for acute reperfusion therapy who are beyond 6 hours
from symptom onset.
Î Either non–contrast-enhanced CT or MRI is recommended before IV
rtPA administration to exclude intracerebral hemorrhage (absolute
contraindication) and to determine whether CT hypodensity or MRI
hyperintensity of ischemia is present (I-A).
Î IV fibrinolytic therapy is recommended in the setting of early ischemic
changes (other than frank hypodensity) on CT, regardless of their
extent (I-A).
