Final answer:
Contrast materials for 'with contrast' CT, CTA, MRI, and MRA procedures are administered via intravenous (IV) injection to enhance the images obtained during these scans.
Step-by-step explanation:
Injection of this type of contrast material is part of procedures such as "with contrast" CT (Computed Tomography), CTA (CT Angiography), MRI (Magnetic Resonance Imaging), and MRA (Magnetic Resonance Angiography). The contrast material is typically administered by the intravenous (IV) route. This involves injecting the contrast agent into a vein, which allows the material to circulate through the bloodstream and enhance the images of the body's structures.
For example, in MRI, a paramagnetic metal cation forms a stable complex known as an MRI contrast agent. Once injected, it alters the magnetic properties of water in cells, providing highly detailed images of soft tissues by differentiating various cellular environments. Gadolinium (Gd³+) is one common metal ion used, administered as a stable complex like DTPA³¯ to avoid toxicity and ensure safe excretion.