Radiologic Technologist Practice Exam

What type of contrast medium dissociates into two molecular particles in water?

1. nonionic agents

2. hydroxyl groups

3. amine groups

4. ionic agents

The correct answer is: ionic agents

The correct answer is that ionic agents dissociate into two molecular particles when mixed with water. Ionic contrast media are composed of molecules that contain ions, which can separate when dissolved, resulting in an increase in the effective osmolarity of the solution. This dissociation is important because it helps to provide better density and contrast during imaging procedures. Ionic agents generally have a higher osmolality compared to nonionic agents because they break apart and release more particles into the solution. This characteristic can influence the patient's reactions and the quality of images produced, as high osmolality can lead to side effects such as discomfort during administration or adverse reactions. Nonionic agents, on the other hand, do not dissociate in this manner and remain as a single particle in solution, which tends to make them safer and more comfortable for patients. Hydroxyl groups and amine groups are functional groups found within molecules but do not pertain specifically to the dissociation characteristics of contrast media. Therefore, understanding the nature of ionic agents and their behavior in water is crucial for radiologic technologists in choosing the appropriate contrast medium for imaging studies.