12-3. Describe a method with a radioactive nuclide to determine the

volume of a large container.

12-4. The following count rates were recorded 24 hours after administration

of 0.4 MBq of 131I to the patient:

For the patient’s thyroid 1831 cpm

For the patient’s thyroid shielded by a lead block 246 cpm

For a standard source in a thyroid phantom 3942 cpm

For a standard shielded by a lead block 214 cpm

What is the percent uptake?