Units of Activity in Nuclear Medicine

📚 Topic Summary

In nuclear medicine, we use specific units to quantify the amount of radioactive material present. This measurement, called activity, indicates the rate at which a radioactive substance undergoes decay. The two primary units are the Curie (Ci) and the Becquerel (Bq). The Becquerel is the SI unit, representing one decay per second. The Curie, an older unit, is still commonly used and is defined as the activity of a quantity of radioactive material in which 3.7 x $10^{10}$ nuclei decay per second. Understanding these units is crucial for accurate dosing and safety in nuclear medicine procedures.

🧪 Part A: Vocabulary

Match the terms with their definitions:

1. Term: Curie (Ci)
2. Term: Becquerel (Bq)
3. Term: Activity
4. Term: Decay
5. Term: Half-life

1. Definition: The process by which an unstable atomic nucleus loses energy by emitting radiation.
2. Definition: The rate at which a radioactive substance undergoes nuclear transformations.
3. Definition: The time required for half of the radioactive atoms in a sample to decay.
4. Definition: A unit of radioactivity equal to 3.7 x $10^{10}$ decays per second.
5. Definition: The SI unit of radioactivity, equal to one decay per second.

🧮 Part B: Fill in the Blanks

Complete the following paragraph with the correct terms.

The ________ (1) is the SI unit of activity and represents one ________ (2) per second. A larger unit, the ________ (3), is equal to 3.7 x $10^{10}$ ________ (4) per second. Knowing the ________ (5) of a radioactive isotope helps determine how quickly it will decay.

🤔 Part C: Critical Thinking

Why is it important to accurately measure the activity of radioactive materials used in nuclear medicine?