Topic 48

Question 1

What is the use of radioactive tracers?

Answer 1

Radioactive isotopes movements, accumulation and fate can be traced

Question 2

How can tracers be used in organs?

Answer 2

Atoms of an organ is exchanged for a radiocative iostope, letting the function of the organ be seen.

Question 3

A molecule which has been exchanged with an isotope

Answer 3

Labelled Molecule

Question 4

What is an advantageous method of radiactive tracers?

Answer 4

Using isotopes of short half-life (Minutes, Hours)

Using Gamma-photos as they are less absorbed.

Question 5

70% of tracings use…

Answer 5

⁹⁹Tc (Half Life of 6 hours)

Product washed with NaCl solution

Question 6

What are in-vitro mothods used for?

Answer 6

To determine volumes of hormones

Radioimmunoanalysis

Question 7

What are In-vivo applications of isotopes?

Answer 7

Diagnostic of thyroid gland (Iodine uptake measured)

Measure blood volume

Question 8

Give the equation to calculate blood volume with radioactive isotopes

Answer 8

V = V₀((C₀/C)-1)

• V₀ = Volume of radioactive solution*
• C₀ = Specific activity of solution*