Lecture 3 Neuroimaging Techniques 1

Question 1

What does CT stand for?

Answer 1

Computed Tomography

Question 2

Describe how a CT works.

Answer 2

Based on X-Rays. The depth of the rays shows how dense the tissue is. X-Ray beam is put into a circular gantry and then spin the X-Ray around so enough information can be gathered to see internal structures past bone.

Question 3

Why does bone appear bright and air appear dark on a CT scan?

Answer 3

Bone blocks the greatest number of X-Rays giving it a bright appearance. Air blocks no X-Rays so gives a dark appearance.

Question 4

What does MRI stand for?

Answer 4

Magnetic resonance imaging

Question 5

Describe how an MRI works.

Answer 5

Interested in the nucleus of hydrogen atoms. Radio signals absorbed by the hydrogen protons and a magnetic resonance signal is omitted.

Question 6

What is a T1 weighted scan?

Answer 6

Characterised by CSF being dark and showing the contrast between white and grey matter.

Question 7

What is a T2 weighted scan?

Answer 7

Shows liquid structures being very bright.