Radiology Practice Test 2026 - Free Radiology Practice Questions and Study Guide

Iodine contrast is commonly used in CT scans because it has high radiopacity, which significantly enhances the visibility of internal structures during imaging. When iodine-based contrast agents are introduced into the body, they absorb X-rays more effectively than surrounding tissues. This results in improved differentiation between various anatomical structures and pathologies, making it easier for radiologists to identify abnormalities such as tumors, blood clots, or vascular issues.

Iodine contrast can be administered intravenously for vascular studies or orally for gastrointestinal imaging, depending on the area being examined. Its effectiveness in enhancing the contrast between different tissues helps provide clearer, more detailed images during CT evaluations.

Other substances like gadolinium are typically used in MRI rather than CT scans, while barium is primarily utilized for gastrointestinal studies rather than general CT imaging. Carbon dioxide can be used in specific cases such as in certain vascular studies, but it is not as commonly employed as iodine-based agents in routine CT scans.