CAMRT Radiography Practice Exam

What is the purpose of using a saline flush after contrast injection during a CT scan?

1. To hydrate the patient

2. To reduce the risk of allergic reactions

3. To decrease artifacts from dense contrast

4. To enhance image quality

The correct answer is: To decrease artifacts from dense contrast

Using a saline flush after contrast injection during a CT scan serves the purpose of decreasing artifacts from dense contrast. When iodinated contrast media is administered, it can sometimes lead to streaking artifacts on the images due to the high density of the contrast agent compared to surrounding tissues. This is particularly relevant in situations where the contrast might not fully clear from the region of interest. The saline flush helps to dilute and wash away the contrast that may linger in the vascular system. This process helps ensure that the imaging fields are not obscured by residual contrast that can contribute to image degradation. By clearing out the dense contrast agent, the saline flush enhances the clarity of the structures being imaged and improves the overall quality of the CT scans. With regard to the other options: while hydrating the patient and reducing the risk of allergic reactions are valid considerations in contrast administration, they are not the primary purpose of using a saline flush in this context. Enhancing image quality is somewhat related, but the direct action served by the saline flush is more specifically aimed at minimizing artifacts rather than general enhancement of image quality.