L13 - Imaging the brain (HM)

Question 1

What is the principle of computerised tomography (CT)

Answer 1

uses x-rays to create images of the brain

x-ray absorption varies by tissue density - denser tissue absorbs more x-rays

images are constructed form x-ray scans taken from multiple angles

Question 2

What are CT scans used for?

Answer 2

diagnoses diseases. or. injuries (e.g., internal bleeding)

typically not used in research due to lower spatial resolution

involves small amounts of radiation

Question 3

What is the principle of Magnetic Resonance Imaging?

Answer 3

based on the behaviour of hydrogen atoms in a magnetic field

strong magnets align hydrogen protons, and radiation waves alter their orientation

the MRI signal is generated as protons return to their aligned state

Question 4

what to Functional Magnetic Resonance imaging (fMRI) do?

Answer 4

Measures BOLD signal to infer brain activity.

High spatial resolution, poor temporal resolution.

Question 5

what do Functional Near-Infrared Spectroscopy (fNIRS) do?

Answer 5

Measures blood oxygenation through optical absorption.

Good temporal resolution, limited spatial resolution.

Question 6

What do PET scans do?

Answer 6

Measures biochemical changes using radioactive tracers.

Moderate temporal and spatial resolution; detects diseases and conditions early.