Certified Respiratory Therapist Practice Exam

A PET scan is most useful in diagnosing which of the following diseases?

1. COPD

2. Bronchogenic carcinoma

3. Tuberculosis

4. Pneumonia

The correct answer is: Bronchogenic carcinoma

A PET scan, or Positron Emission Tomography scan, is particularly useful in the diagnosis and management of bronchogenic carcinoma, which is a type of lung cancer that originates in the bronchi. The scan is effective because it allows for the visualization of metabolic activity in tissues; cancer cells, such as those found in bronchogenic carcinoma, typically have a higher metabolic rate than normal cells. Therefore, they absorb more of the radioactive glucose used in the scan, making them more detectable. In contrast, the other options are primarily assessed through other imaging methods or clinical evaluations. For example, COPD is usually diagnosed using spirometry and clinical history, while tuberculosis is identified through a combination of clinical symptoms, sputum tests, and radiographic images. Pneumonia is typically diagnosed using physical examination and chest X-rays. Thus, while all these diseases affect the respiratory system, the PET scan's specific capabilities make it most beneficial for detecting bronchogenic carcinoma, emphasizing its use in oncology rather than in infectious or chronic obstructive lung diseases.