Radiology Practice Test

Which contrast agent type is frequently used in CT scans to enhance images?

1. Gadolinium-based agents

2. Iohexol

3. Contrast-enhanced ultrasound agents

4. Mix of barium and water

The correct answer is: Iohexol

Iohexol is widely used as a contrast agent for CT scans due to its unique properties. It is an iodinated contrast medium that enhances the visibility of anatomical structures and pathological conditions in imaging studies. The iodine content in iohexol is key, as it provides high radiopacity, which means it effectively absorbs X-rays. This absorption creates a significant difference in imaging contrast, allowing for clearer delineation of blood vessels, organs, and any potential abnormalities such as tumors or lesions. Its rapid excretion through the kidneys also makes it ideal for dynamic studies, where timing and clarity during imaging are crucial. This contrasts with other agents like gadolinium-based agents, which are typically used in MRI rather than CT, and barium, which is primarily used in gastrointestinal studies. Contrast-enhanced ultrasound agents differ in that they do not provide the same level of detail for the types of areas typically assessed in CT imaging. Overall, iohexol’s efficiency and effectiveness for CT scans make it a standard choice in radiology practice.