Acute Stroke Management - American Society of Neuroimaging
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Transcript Acute Stroke Management - American Society of Neuroimaging
Introduction to MRI Head Imaging
Ryan Hakimi, DO, MS
Director, Critical Care Neurology
Assistant Professor
Department of Neurology
The University of Oklahoma Health Sciences Center
January 16, 2015
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DISCLOSURES
FINANCIAL DISCLOSURE
Nothing to disclose
UNLABELED/UNAPPROVED USES
DISCLOSURE
Nothing to disclose
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Objectives
Describe the pros and cons of MRI versus CT when
imaging the head
Discuss some common MRI sequences
Illustrate the appearance of acute ischemic stroke on
various MRI head sequences
Present MRI head imaging of other common
neurological diagnoses
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Principles of Magnetic Resonance
Imaging
Uses a magnet and radio waves to create
an image based on changes in alignment
of protons in the tissue
Terminology
Hyperintense (bright, white)
Hypointense (dark, black)
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Advantages of MRI over CT Head
No radiation
Can image in multiple planes (axial,
sagital, coronal, oblique)
Superior soft tissue imaging
Can image some vessels without contrast
(MRA head)
Many different sequences allow for
specialized imaging
Can image the brainstem and cerebellum
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Disadvantages of MRI vs CT Head
Inferior bone imaging
Cost
Longer study time
Images degraded by motion
Can not image patient with pacemaker,
claustrophobia, metallic foreign bodies
(bullet)
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Axial T1
orbit
pons
T1 looks like a CT
CSF is black
(hypointense)
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Sagital T1
atrophy
corpus collosum
pons
cerebellum
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Coronal with contrast (gadolinium)
With contrast can see
hyperintensity of the blood
vessels
Good for visualization of
hyppocampi
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Axial T2
T2 has white
(hyperintense)CSF
lateral ventricles
frontal horn
occipital horn
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DWI brainstem
Breakdown of blood brain barrier
acute ischemic stroke
acute demyelination
acute trauma
Right
pontine
ischemic
infarction
T2 shine
through
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T2* acute ICH
(gradient echo)
Blood will appear black
(hypointense)
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Acute Ischemic Stroke
DWI
T1
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Acute Ischemic Stroke
T2
FLAIR
(fluid-attenuated inversion
recovery)
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Acute Ischemic Stroke
T2*
petechial hemorrhages
within the ischemic
tissue
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MRA (LMCA patent)
Image can be rotated, left is not always on the right side of the screen, must look at labels
anterior
cerebral
artery
middle
cerebral
artery
R
L
internal
corotid
artery
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Normal Pressure Hydrocephalus
Central atrophy (large
ventricles) out of proportion to
peripheral atrophy (minimal
atrophy)
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Meningioma
Extraaxial brain tumor
(outside of the brain) displacing
The brain)
Enhances with gadolinium
Has a dural tail
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Multiple Sclerosis
Periventricular white matter hyperintensities, some of which
enhance, from National MS Center
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GAD with NSF
Puts patients at risk for nephrogenic
systemic fibrosis
Fibrosis of skin, eyes, organs
Gadolinium can not be administered in
patients:
Glomerular filtration rate (GFR) of 30 or less
On dialysis
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Questions
Thank you
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