Positron emission tomography

Question 1

The tracer principle

Answer 1

same chemical properties are share by isotope of the same elements.
Radioactive isotope can be used as indicator of non-radioactive counterpart.

Question 2

Concentration of tracer

Answer 2

usually order of nano(10^-9) or pico(10^-12) moles

Question 3

Most common positron emitting isotope

Answer 3

18 fluorine, 11 carbon, 15 oxygen

Question 4

what radiation positron emitting isotope emit?

Answer 4

g-ray

Question 5

What determine the distribution and concentration the signal?

Answer 5

Determined by radiopharmaceutical (Tracer) and the biological target it interacts with.
The rate of accumulation and clearance of tracer is determined by physiological functions of the body.

Question 6

Specific uptake

Answer 6

uptake of tracer by tracers’ target

Question 7

non-specific uptake

Answer 7

uptake of non-targets

Question 8

what determine the contrast in PET

Answer 8

ratio of specific and non-specific uptake

Question 9

what determine spatial resolution of PET

Answer 9

1. G-ray emitted not exactly 180 degree.
2. postiron range
3. Size of detector.

Question 10

whats TOF

Answer 10

measure the difference of arrival time to the detectors.

Question 11

Strengths of PET

Answer 11

1. Measure physiological changes precede anatomical or structural changes.
2. Extremely sensitive

Question 12

Current clinical applications of PET

Answer 12

1. Cancer
2. Dementia