Imaging

Question 1

How is contrast determined in CT?

Answer 1

By electron density

Question 2

What is white on a ct and what is black?

Answer 2

White - bone

Black - gas

Question 3

How is contrast determined in MRI?

Answer 3

By proton density

Question 4

Contraindications for MRI?

Answer 4

Implanted electronic device

Implanted ferromagnetic field

Question 5

What artificial contrast can be used in Ct?

Answer 5

Iodine

Question 6

What artificial contrast can be used in MRI ?

Answer 6

Gadolinium

Question 7

Advantages of CT?

Answer 7

Fast
Good bone detail
Acute haematoma easily seen

Question 8

Advantages of MRI?

Answer 8

Very good multi plane view

Non-ionising

Question 9

What is hypertensive in MRI -T1?

Answer 9

Fat 
Methemoglobin
Mineral deposition 
Melanin 
Mush

Question 10

What is hypotensive in MRI -T1?

Answer 10

Water

High flow

Question 11

What is hypertensive in MRI-T2?

Answer 11

Water

Fat

Question 12

What is hypotensive in MRI T2?

Answer 12

Blood products
Mineral deposition
Paucity of water/ mobile protons
High flow

Question 13

Indications for angiography?

Answer 13

Investigation of spontaneous subarachnoid haemorrhage
Suspected aneurysm
Carotid stenosis