Neuroradiology Flashcards
What is the best detial for CT and MRI?
CT –> bone
MRI –> soft tissue
What is the main features of CT?
Use of Xray, high radation, low cost, readily available and scan time is short
What is the main features of MRI?
Magenetic field used but no radation, high cost, and not always available and scan time is long
Can you have different Ct windows?
Yes you can have different windows that have a preferance to show different things such as bone fracture or a bleed.
You can have a braina dn bone window
In a stroke emergency what would you use first a CT or MRI and what are you trying to investigate?
You would use a Ct scan and try and identify whether or not is a hemorrhage stroke
On CT what does the different colours indicate/
White is bone
WAter is grey
Air is black
What are the two types of MRI scan?
T1 and T2 weighted MRI
What are the characteristics of a T1 weighted MRI scan?
Grey/white is right
Fluid is dark
Fat is bright
Also bright – protein, melanin, contrast
See anatomy better
What are the characterstics of a T2 weight MRI scan?
Grey/white is wrong
Fluid is bright
Fat is not so bright
See pathology better
What is mass effect?
compression of the brain –>moving things out of the way
When looking at a MRI scan what are you looking for?
Blood Grey/white differentiation Oedema Mass effect Ventricular size Bones
What are all the prefix for the stroke classification?
TAC_ – Total Anterior Circulation
PAC_ – Partial Anterior Circulation -
LAC_ – Lacunar
POC_ – Posterior Circulation
What is the sufix for the stroke classification?
S – Syndrome
_I – Infarct
_H – Haemorrhage
What area is damaged by TAC and what is the symptoms?
Large cortical stroke in middle / anterior
cerebral artery areas.
Diagnosis have all 3 of: All three of the following: 1. Unilateral weakness (and/or sensory deficit) of face, arm and leg 2. Homonymous hemianopia 3. Higher cerebral dysfunction (dysphasia, visuospatial disorder
What area is damaged by PAC and what is the symptoms?
Cortical stroke in middle / anterior
cerebral artery areas
Diagnosis have 2 of the 3: 1.Unilateral weakness (and/or sensory deficit) of face, arm and leg 2. Homonymous hemianopia 3. Higher cerebral dysfunction (dysphasia, visuospatial disorder
What area is damaged by POC and what is the symptoms?
Posterior circulation
Diagnosis by having one of
- Cerebellar or brainstem syndromes
- Loss of consciousness
- Isolated homonymous hemianopia
What area is damaged by LACS and what is the symptoms?
Subcortical stroke due to small vessel dieing
Diagnose by having one of:
Unilateral weakness (and/or sensory deficit)
of face and arm, arm and leg or all three.
Pure sensory stroke.
Ataxic hemiparesis
What is lacunar stroke?
Is a type of stroke that results from a occlusion of a small artery deep in the brain that provide blood to deep brain structurs such as grey matter.
Why should you scan when a stroke patient comes in?
Exclude haemorrhage
Prove ischaemic stroke
When should you do a scan of a person who has had a potential stroke within the hour?
Loss of GCS, if patient on anticoagulant, have GCS that is fluctuating, Focal neurology
What do you do if a Ct scan does not show any sign of stroke on a patient who you think has one?
DWI weighting MRI shows acute stroke
What are the Ct signs of a heamrrhagic stroke?
Blood – hyperdense (bright)
Mass effect
What are the CT signs of a ischeamic stroke?
Thrombus in vessel – hyperdense (bright)
Loss of grey/white
Oedema – hypodense (dark)
Mass effect
What are the different types of extra axial haemorrhage?
Extra dural
Sub-dural
Sub-arachanoid
What is the indication of the age of the haemorrhage?
Acute –> Hyperdense –>Bright
Sub-acute –> Isodense –> Grey
Chronic –> Hypodense –> Dark
What occurs in Subarachnoid haemorrhage?
Bleeding between the Arachanoid and Pia matter
The blood occupies the CSF spaces - sulci, fissures, ventricles, basal cisterns
Cause of Subarachnoid haemorrhage?
Traumatic
Spontaneous
Ruptured aneurysm
What are the symptoms of Subarachnoid haemorrhage?
Worst-ever’ / ‘thunderclap’ headache
Blood irritates meninges
Vomitting
What occurs in extradural haemorrhage?
Damage to the middle meningeal artery usually such as trauma to the Pterion region. Build up of blood between the skull and dura matter
Usually occur with a fracture
What is the consequence of extradural heamorrhage?
Dura is peeled off the skull
Loss of grey and white matter differentiation
How is extradural heamorrhage treated?
Treated with burr hole to relieve the pressure on the brain
What is the cause of Subdural haemorrhage and where does it occur?
Between dura and arachnoid mater
Usually tearing of bridging veins that cross the dural space
Venous bleed
Gradual increase in headache and confusion
Who are at more risk of subdural haemorrhage?
Elderly people and alcoholics –> shrunken brain so less of a good fit.
People on anticoagulant medication
Cause is usually trauma
What shape is the subdural haemorrhage?
Subdural haematoma forms a crescent-shaped collection
What shape is formed by extradural haemorrhage?
Forms a lens-shaped collection
What does coup and contre-coup inuury mean in terms of head injury?
In head injury, a coup injury occurs under the site of impact with an object, and a contrecoup injury occurs on the side opposite the area that was hit.
