Radiology Practice Test

What is the main purpose of digital subtraction angiography (DSA)?

1. To visualize internal organs

2. To measure bone density

3. To visualize blood vessels and identify blockages or anomalies

4. To conduct skin examinations

The correct answer is: To visualize blood vessels and identify blockages or anomalies

Digital subtraction angiography (DSA) primarily serves the purpose of visualizing blood vessels in order to identify any blockages, stenoses, or anomalies. This technique uses a series of X-ray images taken before and after a contrast agent is introduced into the vascular system. By subtracting the pre-contrast images from the post-contrast images, DSA enhances the visibility of blood vessels while minimizing the interference from surrounding structures, such as bones or tissues, which do not contain the contrast medium. This ability to clearly visualize the vascular structures is critical in various clinical scenarios, such as diagnosing vascular diseases, planning for interventional procedures, and evaluating the success of previous vascular interventions. In contrast, other options like visualizing internal organs, measuring bone density, or conducting skin examinations pertain to different imaging modalities or techniques that are not specific to DSA's focus on vascular imaging.