Neuroradiology

Question 1

Sagital image: what is fourth ventricle?

Answer 1

Triangle shaped structure between spinal cord and cerebellum

Question 2

What is the vermis?

Answer 2

Midline part of cerebellum that is covering the fourth ventricle

Question 3

What is best for rapid imaging of patients with hemorrhage or mass effect?

Answer 3

CT

Question 4

What is more sensitive for subtle findings, but requires longer imaging times?

Answer 4

MRI

Question 5

Describe the neuroradiology of MS?

Answer 5

• MRI is preferred imaging modality
• White matter lesion known as plaques show
• Contrast used to assess activity : Areas called active lesions

Question 6

Describe the pathology of MS:

Answer 6

• Immune mediated disease where body starts to attack myelin
• Damaged myelin leads to scar formation (sclerosis) which impairs nerve impulses
• Thought to be related to environmental factors in genetically susceptible patients

Question 7

Encephalitis?

Answer 7

Infection of brain itself

Question 8

Abscess in brain?

Answer 8

More focal walled off collection - infection walled off

Question 9

What happens in a Subarachnoid Hemorrhage?

Answer 9

• Most commonly related to ruptured aneurysm
• Leads to sudden, severe headache, with loss or impairment of consciousness
• If CT negative with strong suspicion may need LP

Question 10

Where is the thalamus on the axial section?

Answer 10

Lateral to the 3rd ventricle

Question 11

When detecting stroke or heart attack, what imaging modality is used first?

Answer 11

CT

Question 12

***What are risk factors for infarction?

Answer 12

• Atherosclerosis (fat and other substances build up in the walls of the arteries)
• High BP
• Diabetes mellitus
• Tobacco use
• Obesity
• Elevated lipids

Question 13

What is intraparenchymal?

Answer 13

Occurring in the body of an organ

Question 14

What is an infarction?

Answer 14

• Caused by blockage in the blood supply
• It can be caused by thrombosis (blockage of vessel due to formation of a clot) or embolism (blockage travels from elsewhere)

Question 15

How can you tell if you’re look at a CT or MRI?

Answer 15

• MRI has more detail, can tell white from gray matter - well differentiated
• CT - bones look white

Question 16

What is MRI good for?

Answer 16

• Best way to assess for acute ischemic changes or infarction
• Special sequences that identify infarcts with in hours
• Best way to assess for demyelinating disease, tumors, or seizure foci

Question 17

Why should you always get CTs without contrast for acute traumas?

Answer 17

-Contrast material appears white/dense and acute hemorrhage on a CT is dense (looks white)

Question 18

When should you use contrast?

Answer 18

• Infection, inflammation and tumor which can all disrupt the BBB
• You can better see the process and its effect on the BBB if you use contrast

Question 19

What happens in a Neonatal US?

Answer 19

• One at 20 weeks used as a screening exam
• Visualization of normal lateral ventricles, normal cavum septum pellucid (below/between lateral ventricles) and a normal appearing posterior fossa can exclude a vast majority of congenital CNS abnormalities

Question 20

What does the corpus callous do?

Answer 20

• Connects the two hemispheres

- Parts: Rostrum, genu, body and splenium parts

Question 21

What is suli?

Answer 21

Depressions in brain, fluid filled

Question 22

What images are used to make diagnoses most often?

Answer 22

Axial/transverse

Question 23

Where is the cerebellar vermis?

Answer 23

-Bottom, back/posterior of the cerebellum

Question 24

What uses ionizing radiation?

Answer 24

CT

Question 25

What is CT good for?

Answer 25

• Rapidly acquired images - great for ER, ICU patients

- Best screen for intracranial hemorrhage or complications related to mass effect (tumor, etc.)

Question 26

When do you use an MRI?

Answer 26

• Only if you have time
• Longer imaging times require a stable, cooperative patient
• Best test for acute ischemia, demyelinating disease, seizure foci or tumors