Generators

Question 1

What are Radionuclide Generator systems used for?

Answer 1

To generate radionuclides for routine clinical practice.

Question 2

What is the most widely used generator system?

Answer 2

Molybdenum (Mo-99) / Technetium (Tc-99m) generator.

Question 3

What is the half-life of Mo-99?

Answer 3

67 hours.

Question 4

What is the half-life of Tc-99m?

Answer 4

6 hours.

Question 5

What type of imaging relies on the Mo-99/Tc-99m generator?

Answer 5

SPECT imaging.

Question 6

What is the half-life of Rb-82?

Answer 6

2 minutes.

Question 7

What generator produces krypton (Kr-81m) for ventilation studies?

Answer 7

Rb-81/Kr-81m generator.

Question 8

What is the half-life of Kr-81m?

Answer 8

13 seconds.

Question 9

What is a characteristic of the Sn-113/In-113m generator?

Answer 9

Parent half-life: 115 days; Daughter half-life: 1.7 minutes.

Question 10

What is the half-life of Ge-68?

Answer 10

280 days.

Question 11

What is the half-life of Ga-68?

Answer 11

68 minutes.

Question 12

What is the half-life of Zn-62?

Answer 12

9.3 hours.

Question 13

What is the half-life of Cu-62?

Answer 13

9.8 minutes.

Question 14

What is the half-life of Sr-82?

Answer 14

25 days.

Question 15

What is the half-life of Rb-82?

Answer 15

1.3 minutes.

Question 16

What is the typical useful life of a Mo-99/Tc-99m generator?

Answer 16

About 3 half-lives or approximately one week.

Question 17

What is meant by ‘milking’ the generator?

Answer 17

Removing the daughter nuclide from the generator.

Question 18

How often should the daughter nuclide be removed from a Mo-99/Tc-99m generator?

Answer 18

Every 6 hours, twice daily or once daily.

Question 19

What are the general characteristics of a radionuclide generator?

Answer 19

Parent has long half-life; daughter has short half-life; different chemical properties.

Question 20

What materials are used in the construction of a generator?

Answer 20

• Glass/Plastic tube
• Chromatography column
• Lead shield/pack
• Source of eluent
• Evacuation vials.

Question 21

What is the decay constant?

Answer 21

A factor used in calculating the activity of radionuclides.

Question 22

What is transient equilibrium?

Answer 22

Condition when the activity of the daughter nuclide reaches a maximum as the parent decays.

Question 23

True or False: Transient equilibrium occurs when the half-life of the parent is less than that of the daughter.

Answer 23

False.

Question 24

What is the significance of the ideal generator?

Answer 24

Sterile & pyrogen-free eluate; no violent chemical reactions; room temperature storage.

Question 25

What is the short half-life of Technetium-99m?

Answer 25

6 hours.

Question 26

What is the primary method used to elute Tc-99m from the generator?

Answer 26

Using normal saline through the column.

Question 27

What is the role of alumina in the Mo-99/Tc-99m generator?

Answer 27

It serves as the adsorbent for Mo-99.

Question 28

What is the activity of Tc-99m in relation to Mo-99?

Answer 28

Tc-99m is produced from the decay of Mo-99.

Question 29

What does the term 'elution profile' refer to?

Answer 29

The activity of radionuclides over time after elution.

Question 30

What is the importance of radionuclide generators?

Answer 30

They are easily transportable sources of short-lived radionuclides.

Question 31

Fill in the blank: The half-life of Rb-81 is _______.

Answer 31

4.7 hours.