Which of the following can be used as a positive contrast agent for a cystogram?Group of answer choicesSalineBarium contrastIodinated contrastRoom air

The iodinated contrast can be used as a positive contrast agent for a cystogram. Here's why:

1. A cystogram is a diagnostic procedure that involves taking X-ray images of the bladder.

2. For these images to be clear, a contrast agent is needed. This agent helps to highlight the structures of the bladder, making them more visible on the X-ray.

3. Positive contrast agents are substances that appear white or light on X-ray images.

4. Iodinated contrast is a type of positive contrast agent. It is often used in various radiographic studies, including cystograms.

5. On the other hand, saline and room air are negative contrast agents, meaning they appear dark on X-ray images.

6. Barium contrast is also a positive contrast agent, but it is typically used for gastrointestinal studies, not for cystograms.

So, out of the options provided, iodinated contrast is the most suitable choice for a cystogram.