[Topics in Current Chemistry] Contrast Agents I Volume 221 || Non-Gadolinium-Based MRI Contrast Agents

✍ Scribed by Krause, Werner

• Book ID: 118154753
• Publisher: Springer Berlin Heidelberg
• Year: 2002
• Tongue: English
• Weight: 294 KB
• Edition: 1
• Category: Article
• ISBN: 354045733X
• DOI: 10.1007/3-540-45733-x_6

✦ Synopsis

Extracellular MRI and X-ray contrast agents are characterized by their phar- cokinetic behaviour.After intravascular injection their plasma-level time curve is characeterized by two phases. The agents are rapidly distributed between plasma and interstitial spaces followed by renal elimination with a terminal half-live of approximatly 1–2 hours. They are excreted via the kidneys in unchanged form by glomerular filtration. Extracellular water-soluble contrast agents to be applied for X-ray imaging were introduced into clinical practice in 1923. Since that time they have proved to be most valuable tools in diagnostics.They contain iodine as the element of choice with a sufficiently high atomic weight difference to organic tissue. As positive contrast agents their attenuation of radiation is higher compared with the attenuation of the surrounding tissue. By this contrast enhancement X-ray diagnostics could be improved dramatically. In 2,4,6-triiodobenzoic acid derivatives iodine is firmly bound. Nowadays diamides of the 2,4,6-triiodo-5-acylamino-isophthalic acid like iopromide (Ultravist, Fig. 1) are used as non-ionic (neutral) X-ray contrast agents in most cases [1].