American Society of Radiologic Technologist (ASRT) Practice Exam

The greatest source of medical radiation exposure in the United States is:

1. Radiography.

2. Interventional fluoroscopy.

3. Nuclear medicine.

4. Computed tomography (CT).

The correct answer is: Computed tomography (CT).

The greatest source of medical radiation exposure in the United States is computed tomography (CT). This is primarily due to the high energy levels and the cumulative dose associated with CT scans compared to other diagnostic imaging procedures. CT scans provide detailed cross-sectional images of the body and are frequently used for various medical evaluations, which increases their frequency of use in clinical practice. Radiography generally involves lower radiation doses and is widely used for a variety of standard diagnostic purposes, but the cumulative exposure from CT scans significantly surpasses that from traditional radiographic procedures. Interventional fluoroscopy, while associated with higher doses than standard radiography, is performed less frequently than CT scans. Nuclear medicine involves radioisotope administration, which also contributes to radiation exposure but generally occurs in a more limited context. Thus, due to its widespread usage and the higher doses associated with each scan, CT stands out as the leading source of medical radiation exposure.