Neuroradiology of Stroke and Headaches
Learning Objec:ves 1. Iden:fy T1 and T2 sequences 2. Recall the normal anatomy of the intracranial circula:on 3. Apply appropriate CT and MR imaging of the brain in acute stroke
Learning Objec:ves 4. Differen:ate acute from chronic infarct on CT 5. Classify primary and secondary headaches 6. Formulate appropriate imaging algorithms for headache
Learning Objec:ves 7. Recognize subarachnoid hemorrhage on noncontrast head CT 8. State common loca:ons of intracranial aneurysms 9. Describe treatment op:ons for pa:ents with intrcranial aneurysms
What type of imaging modali:es are used to evaluate the brain in pa:ents presen:ng with acute stroke?
Axial NECT head
What is the most sensitive method for detection of acute ischemia in the brain?
Describe factors which influence which modality is chosen to image pa:ents with acute stroke.
What modali:es can be used to evaluate the cerebral vasculature?
Pros and Cons of Vascular Exams Exam Pro Con MRA/MRV CTA/CTV Catheter based Angiogram or Venogram 11
Pros and Cons of Vascular Exams Exam Pro Con MRA/MRV Noninvasive/Minimally Invasive (if iv contrast) No radia:on No contrast Exam :mes long Coopera:on needed/quality inconsistent Not always available in some centers CTA/CTV Minimally invasive (iv required) Quick Immediately available Radia:on dose Contrast required Catheter based Angiogram or Venogram Gold standard High resolu:on of vascular detail Offers endovascular access if needed Radia:on dose Contrast required Invasive Morbidity/Mortality Necessitates angiography team Expensive 12
ACA MCA ICA PCA SCA basilar AICA PICA vert
ACA MCA basilar PCA ICA vert
What vessel connects the anterior and posterior circula:on? Where would you draw it?
Describe a clinical scenario where MRA is indicated.
lateral oblique coronal
superior sagittal sinus sigmoid sinus torcula transverse sinus Internal jugular internal cerebral veins sigmoid sinus Internal jugular vein of Galen superior sagittal sinus straight sinus transverse sinus torcula MRV
How might this pa:ent have presented? Axial NECT head
What are the findings? Axial NECT head
24
Normal Normal extracellular space neuron Cytotoxic Edema in Infarc:on Extracellular space decreased and diffusion limited swollen neuron extracellular diffusion > intracellular diffusion 25
At what point aber the onset of stroke like symptoms does DWI become posi:ve? 26
55 yo female with new right hemiparesis, right neglect and expressive aphasia
Explain the discordance in the findings between these two studies. Axial NECT head MRI Axial DWI
67 yo male with 2 hours of new onset of right sided weakness. What is in your differen:al diagnosis?
What imaging study would you order?
67 yo male with 2 hours of new onset of right sided weakness
Coronal NECT head Axial NECT head What occurred in the interval?
Coronal NECT head Axial NECT head What are the signs of mass effect?
How does hemorrhagic transforma:on of ischemic infarct occur?
Axial NECT head Acute vs. chronic Coronal NECT head
Acute vs. chronic MRI axial DWI MRI axial T2 MRI axial ADC
19 yo female c/o headache gradually worsening over 3 days and decreased visual acuity. She is obese, takes oral contracep:ves and has papilledema on phys exam. What is in your differen:al diagnosis?
What type of imaging examina:on should be ordered?
Axial NECT head
Normal Pa:ent 40
What are the pa:ent s risk factors?
What are other risk factors associated with venous sinus thrombosis?
Now let us turn to this pa:ent s MRI. What do we expect to see on the DWI?
Can you give examples of other secondary headaches?
What are examples of primary headaches?
41 yo male with sudden onset of severe h/a. Denies history of h/a in past. What should be done next for this pa:ent?
When should a non- enhanced CT head be ordered in the clinical segng of headache?
41 yo male with sudden onset of severe headache. Axial NECT head
What imaging examina:on should be performed next?
What if the CT angiogram is nega:ve?
What are the treatment op:ons for ruptured aneurysm?
What are the advantages and disadvantages to each?
AP XR skull Axial NECT head bone window
What are the most common loca:ons of intracranial aneurysms? Why?
How do aneurysms cause headaches?
What examina:ons can be used to detect aneurysms?
Aneurysm found on screening MRA. Where is it located? MRA MIP MRA axial source images
Who is at increased risk for developing aneurysms?
Who should be screened?
What is the preferred modality for aneurysm screening?
52 y.o. male w/hx of 4 mm right paraophthalmic aneurysm found on CT angiography performed aber high speed MVA resul:ng in skull base fractures. Sagittal CT angiography Coronal CT angiography
54 yo female w/ long hx of h/a, photophobia and phonophobia Primary or secondary headache?
What are the indica:ons to order an MRI in the clinical segng of headache?
54 yo female w/ long hx of h/a, photophobia and phonophobia
54 yo male with 2 wks of fever, malaise and h/a. Now has increasing right arm and right facial weakness. PMHx of IVDA which currently denies. Primary or secondary h/a?
What is in your differen:al diagnosis?
What type of imaging study would you order?
T1 T1 gad 2 weeks fever, malaise and h/a. Now with increasing right arm and right facial weakness T2
T1 T1 gad How would you describe this lesion? T2 MRI axial T1 MRI axial T1 gad MRI axial T2 MRI axial DWI
T1 T1 gad How does the restricted diffusion shape your differen:al? T2 T1 T1 gad T2 DWI
T1 T1 gad Why is this NOT an infarct? T2 T1 T1 gad T2 DWI
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