1. 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

2. DISCLOSURES FINANCIAL DISCLOSURE UNLABELED/UNAPPROVED USES DISCLOSURE
Nothing to disclose
UNLABELED/UNAPPROVED USES DISCLOSURE

3. 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 3

4. 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)

5. 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

6. 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)

7. Axial T1
T1 looks like a CT
CSF is black
(hypointense)
orbit
pons

8. Sagital T1
atrophy corpus collosum pons cerebellum

9. Coronal with contrast (gadolinium)
With contrast can see hyperintensity of the blood vessels Good for visualization of hyppocampi

10. Axial T2 T2 has white (hyperintense)CSF lateral ventricles
frontal horn
occipital horn

11. DWI brainstem
Breakdown of blood brain barrier acute ischemic stroke acute demyelination acute trauma
Right pontine ischemic infarction
T2 shine through

12. T2* acute ICH
(gradient echo)
Blood will appear black
(hypointense)

13. Acute Ischemic Stroke DWI T1

14. Acute Ischemic Stroke T2 FLAIR (fluid-attenuated inversion recovery)

15. Acute Ischemic Stroke T2*
petechial hemorrhages within the ischemic tissue

16. MRA (LMCA patent) anterior cerebral artery middle cerebral artery L R
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 L R
internal corotid artery

17. Normal Pressure Hydrocephalus
Central atrophy (large
ventricles) out of proportion to
peripheral atrophy (minimal
atrophy)

18. Meningioma Extraaxial brain tumor (outside of the brain) displacing
Enhances with gadolinium
Has a dural tail

19. Multiple Sclerosis
Periventricular white matter hyperintensities, some of which enhance, from National MS Center

20. 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

21. Questions
Thank you
OU Neurology