1. Hot Lab 2 Problem Solving12
Hot Lab 2
Problem Solving

2. Q 1
If a bone scan has been ordered on a 5-year-old girl, and the physician prescribes 60% of the adult dose to be given, how many mCi should be administered?

3. Q 2
If the biological half-life of an isotope is
6 hours, and the physical half-life is 12hrs,what is the effective half-life?

4. Q 3
A vial containing 99mTc is assayed at 9:00 a.m. And contains 255 mCi.
To calculate the remaining activity at 3:00 pm

5. Q 4
If a kit contains 140 mCi of 99mTc in 20 ml, how much volume must be withdrawn to obtain a dose of 5 mCi?

6. Q 5
If a radiopharmaceutical is spilled on the floor, the first
priority is to:
a. contact the Radiation Safety Officer
b. pour a chelating solution over the area of the spill
c. cover the area with absorbent paper and restrict access
around it
d. call the housekeeping department to arrange
for cleaning

7. Q 6
A vial of technetium eluate contains 50 mCi/ml. If 4 ml are withdrawn and added to a diphosphonate kit containing 16 ml of solution,what volume would then need to be withdrawn to prepare a 20 mCi dose at that moment?

8. Half value layer HVL
The thickness of any given material where 50% of the incident energy has been attenuated is know as the half-value layer (HVL).
The HVL is expressed in units of distance (mm or cm) of thickness of the shielding material (usually lead).

10. The HVL is often used in nuclear medicine simply because it is easier to remember values and perform simple calculations for shielding.
It can be seen that if the thickness of one HVL is known, it is possible to quickly determine how much material is needed to reduce the intensity to less than 1%.

11. Half-lives of radiopharmaceuticals
The physical half-life (Tp) of a radiopharmaceutical is the amount of time necessary for the radioactive atoms to decay to one half their original number.
Each radionuclide is characterized by a specific half-life that is a physical constant

13. Prof. Dr. Omar Shebl Zahra
Thank you and Good Luck
Prof. Dr. Omar Shebl Zahra