Final answer:
The statement that an ionic contrast agent is a low osmolality agent is false; ionic contrast agents usually have a high osmolality compared to plasma.
Step-by-step explanation:
An ionic contrast agent is not a low osmolality agent. This statement is false. Contrast agents such as iodine-based or gadolinium-based compounds, which are ionic in nature, tend to have a high osmolality compared to the plasma. High osmolality can cause more side effects, which is why non-ionic, low-osmolality contrast agents have been developed to provide a safer alternative for imaging procedures like MRI and CT scans. Gadolinium (Gd³⁺), due to its highly paramagnetic nature with seven unpaired electrons, is used in its complexed form, usually with DTPA³⁻ (diethylene triamine pentaacetic acid), to avoid toxicity and enhance the contrast in MRI scans of soft tissues.