Neuroimaging

Question 1

What are the 3 different possible orientations?

Answer 1

• Sagittal,
• Transverse,
• Coronal

Question 2

What are cisternas?

Answer 2

Openings in the subarachnoid space in the brain create by the separation of the arachnoid and pia mater

Question 3

What are the ABCS of CT/MRI interpretation?

Answer 3

A - Adequacy, alignment and artefact.
B - Bones, blood and brain,
C - Cisterns and ventricles,
S - Subcutaneous and surfaces and symmetry

Question 4

Describe the appearance of an extradural haematoma

Answer 4

Will be found between skull and outer later of dura. It will look biconvex (limited by cranial sutures)

Question 5

Describe the appearance of a subdural haematome

Answer 5

This will be found between the dura and arachnoid mater. It will appear as a crescent shape. There can be parenchymal shift.
Old blood is a dark grey - indicates the bleed is chronic whereas in acute bleeds the blood will appear white

Question 6

What is diffuse axonal injury?

Answer 6

It is a traumatic brain injury due to shearing forces. It will appear with poor grey-white matter differentiation and loss of sulci. may have association with haemorrhage.

Question 7

Where will blood collect in a subarachnoid haemorrhage?

Answer 7

Within cisterns

Question 8

How will obstructive hydrocephalus appear?

Answer 8

enlarged ventricles as there is a blockage in the ventricular system.

Question 9

What areas do you want to be looking at under S - subcutaneous and soft tissues

Answer 9

• Skin/subcutaneous lesions,
• Orbit,
• Sinuses,
• Nasopharynx and oropharynx

Question 10

Describe the appearance of a meningioma

Answer 10

Homogenous, well circumscribed, broad Dural base growth. Patients are often asymptomatic so accidental finding

Question 11

What are the risk factors for an haemorrhagic stroke?

Answer 11

Hypertension, ischaemic stroke, anticoagulation and amyloid angiopathy.

Question 12

What do MRI measure?

Answer 12

The speed at which it takes nuclei to return to their original orientation after radiofrequency pulses cause them to flip.

Question 13

Describe features of T1 imaging

Answer 13

Best for structural imagine, in this scan type the grey matter is darker than white matter. water is dark

Question 14

Describe features of T2 imaging

Answer 14

This is good for identifying pathology such as inflammation or oedema. Think WW2 Water is white, white matter is darker than grey matter

Question 15

What are two important MRI variants?

Answer 15

DWI - Diffusion weighted. This is a T2 based sequence that measures diffusion of water within tissues.
ADC - Apparent diffusion coefficient. Calculated from DWI, shows pure diffusion

Question 16

Why are DWI/ACD used in acute stroke imagine?

Answer 16

in acute stokes cells are starved of O2 so the membrane channels allow less diffusion.

Question 17

What is an MR venogram?

Answer 17

Technique that can be used to track blood flow through veins, no contrast is required

Question 18

How can multiple sclerosis be visualised on MRI scanning

Answer 18

In T2/FLAIR imaging it appears as hyperintense plaques.
In T1 it appears as hypointense but hyperintense in advance disease