Brain Health and Dementia 2a

Question 1

What is horizontal plane also known as?

Answer 1

Transverse.

Question 2

Describe transverse plane?

Answer 2

cutting horizontally

Question 3

Describe frontal / coronal plane?

Answer 3

cutting down through left to right

Question 4

Describe sagittal plane

Answer 4

cutting down through the front.

Question 5

What does PET scan stand for?

Answer 5

Positron Emission Tomography.

Question 6

What is a Positron ?

Answer 6

Opposite particle to the electron
It is a particle
Positively charged
Symbol : β+ or e+
Emitted during radioactive decay

Question 7

What is tomography?

Answer 7

Tomography is an x-ray technique in which shadows of superimposed structures are blurred out by a moving x-ray tube and produce detailed images of internal structures.

Question 8

What is a positron the equivalent of?

Answer 8

The positively charged equivalent of an electron.

Question 9

What is this an equation for? p → n + β^+ + νe

Answer 9

Beta plus decay generic equation.

Question 10

Describe the equation for Beta Plus decay?

Answer 10

p → n + β^+ + νe

a proton decays into a neutron + positron + electron neutrino

Question 11

Whats the charge of an electron?

Answer 11

negative charge (-)

Question 12

Whats the charge of a positron?

Answer 12

positive charge (+)

Question 13

What is the charge of a neutrino?

Answer 13

0. Neutral charge.

Question 14

What is neutrino represented by?

Answer 14

v

Question 15

When are positrons emitted?

Answer 15

During radioative decay, also known as Beta+ decay (B^+)

Question 16

What does a proton decay into in beta + decay?

Answer 16

a proton decays into a neutron + positron + electron neutrino

Question 17

How often do positrons occur naturally?

Answer 17

almost never occurs naturally

Question 18

What is the brains main source of energy?

Answer 18

Glucose is used as the main source of energy (krebs cycle).

Question 19

Where in the brain is glucose used?

Answer 19

is used in the brain in the neurons and the cells.

Question 20

What does the brain need in order to function?

Answer 20

The brain needs energy.

Question 21

How could we measure where is glucose used ?

Answer 21

Use of non-hydrolysable (non-degradable) glucose molecules (glucose analogues)
- [18F] fluorodeoxyglucose
- used as a marker (tracer)

Question 22

What do PET scans detect?

Answer 22

PET scans detect the emission of protons via indirect detection of the energy emitted by the 2 photons travelling in opposite directions.

Question 23

Describe how a PET scan works.

Answer 23

1) Radioactive atom produces a positron
2) Travels a minute distance until it meets and electron. This distance is very small.
3) Positron and electron react and create a neutral charge.
4) Annihilation. Needs to release energy and does so by forming photons (Y) which travel in opposite directions.
5) Each photon has 511 keV. kiloelectronvolts.
6) t2 does not have to travel far to be detected by the machine so will be quick.
7) t1 has to travel further so will take more time for detection.

Question 24

What are the different types of coincident events?

Answer 24

True coincidence, random (accident) coincidence, and scattered coincidence.

Question 25

What is different with random (accident) coincidence, and scattered coincidence?

Answer 25

The annihilation event does not lie on the apparent line of response between two photon detectors.

Question 26

What type of detectors are involved in PET scans?

Answer 26

photon detectors.

Question 27

WHat is [18F] FDG used for?

Answer 27

use for visualization of metabolism

Question 28

What is [15O] used for?

Answer 28

Used for visualisation of blood flow.