Neuroradiology + Embryology

Question 1

How do you distinguish a CT from MRI?

Answer 1

CT- (see teeth) bone is white, CSF is black

Question 2

What neurological suspected pathology would require a CT scan?

Answer 2

Head Trauma
Acute Stroke
Headache (red flag for tumour/ subarachnoid)
Cancer (mets)
Post Surgical- hydrocephalus, Haemorrhage

Question 3

What neurological presentation would be contraindicative to a CT?

Answer 3

GCS 15
No open/ depressed skull fracture
No CSF leakage
No panda eyes
<2 vomiting episodes
No amnesia
<65
Fall <1m
Seizure-MRI

Question 4

What type of imaging shows white CSF?

Answer 4

T2 MRI

Question 5

What does bone look like vs fat on an MRI?

Answer 5

Dark bone surrounded by white fat

Question 6

What neurological suspected pathology would require an MRI scan?

Answer 6

Demyelination- MS
CNS tumours
Spine- IV disk prolapse
TIAs
Epilepsy
Paediatric Neurology
Headache- IC Hypertension
Cancer

Question 7

What physical/ psychological complications would prevent a Pt from an MRI scan?

Answer 7

Implants- electronics, cardiac pacemakers, defibs, cochlear implants
Shunts
Insulin pumps
Moveable- Aneurysm clips, heart valves, recent intra-abdominal clips
Claustrophobia
Pregnancy
Tattoos

Question 8

What is the purpose of an angiography?

Answer 8

Look for large vascular (arterial + venous) abnormalities
Aneurysm
Arterio-Venous Malformation
Carotid Cavernous Fistula
Unstoppable epistaxis  (nosebleed)

Question 9

What is the purpose of Ct perfusion?

Answer 9

See the volume of blood passing through a defined volume of tissue per unit of time
Look for strokes (Dec perfusion), Tumour (INc perfusion- angiogenesis, aggressive)

Question 10

What is the purpose of a PET Scan?

Answer 10

Map out glucose usage (inc metabolism in tumour, inflammation + infection). useful after brain tumour resection for differentiating granulation tissue (low energy use) from leftover tumour (high energy use)

Question 11

What embryological layer does the nervous system develop from?

Answer 11

Ectoderm

Question 12

The 3 primary brain vesicles (forebrain, midbrain + hindbrain) develop into 5 secondary vesicles what are the adult derivatives of these?

Answer 12

1. Tiencephalon- Hemispheres, Hippocampus, Basal Ganglia
2. Diencephalon- Thalamus (+hypo), Pituitary, Pineal
3. Mesencephalon- Sup + Inf Colliculi
4. Metencephalon- cerebellum + pons
5. Myelncephalon- Medulla

Question 13

What is the difference between gyrus + sulci? How are they formed?

Answer 13

Sulcus- Groove
Gyrus- Raised
Folds as a results of rapid growth to give more space

Question 14

What are the 2 types of neural epithelial cells? How do they develop and what do they produce as a result?

Answer 14

Neuroepithelial Cells- pseudostratisfied epithelium- ependymal cells- Nuerones, Astrocytes (proteoplastic, fibrous), Oligiodentrycytes

Neural Crest Cells–migrate- between somites (=DRG); organs (sympathetic + parasympathetic ganglia); gut (enteric NS); meninges, adrenal medulla, facial bones + cartilage