Radiology Practice Test

Which imaging technique uses radioactive tracers to assess organ function?

1. Computed Tomography (CT)

2. Magnetic Resonance Imaging (MRI)

3. Fluoroscopy

4. Positron Emission Tomography (PET)

The correct answer is: Positron Emission Tomography (PET)

Positron Emission Tomography (PET) is a specialized imaging technique that employs radioactive tracers, known as radiotracers or radiopharmaceuticals, to evaluate organ function and metabolic processes in the body. During a PET scan, these radiotracers are injected, inhaled, or ingested, and they emit positrons as they decay. The unique aspect of PET imaging lies in its ability to visualize physiological functions rather than just anatomical structures. This is particularly useful in oncology to detect cancerous tissues, as cancer cells often have higher metabolic activity than normal cells. By assessing the distribution of the radioactive tracers in organs and tissues, PET can help in diagnosing diseases, planning treatment strategies, and monitoring the effectiveness of therapies. Unlike techniques such as CT and MRI, which primarily focus on structural imaging to assess anatomy, PET provides insights into how well organs are functioning and their metabolic state. Fluoroscopy, while useful for real-time imaging of moving structures like the gastrointestinal tract, does not specifically assess organ function through metabolic processes using radioactive tracers. Therefore, PET stands out as the correct choice for the assessment of organ function through the use of radioactive materials.