For healthcare providers, the package insert and the prescribing information is the locally appropriate and always updated contrast agent specific information source. TEA MR CONTRAST AGENT HOW TOThe regulatory approval by an agency such as the Food and Drug Administration (FDA) in the United States defines the indicated use frequently-also referred to as the labeled use-as well as how to use it appropriately, any warnings and contraindications. Therefore, we will initially discuss the development and safety of MR contrast agents before we will review some of their type-specific characteristics for cardiovascular MR and MRA. 2 We also experience a substantial variability in country specific availability of MR contrast agents for cardiovascular imaging as well as regulatory approvals, which is especially evident for cardiovascular imaging. For cardiovascular MR imaging, we classify today’s available agents into paramagnetic (mostly gadolinium-based) and super-paramagnetic (mostly iron oxide-based). For example, all contrast agents for x-ray computer tomography (CT) use iodine as their central ion, whereas MR contrast agents depend on the magnetic moment of the central atom. MR contrast agents generate image contrast by locally changing the relaxivity of the recipient tissue. Radiographic contrast agents lead to an attenuation of the transmitted x-rays MR agents rely on a completely different biophysical principle. The value of a contrast agent depends on its ability to generate image contrast for a given imaging modality. 1 This chapter will focus solely on those MR contrast agents that have, or promise to have, value for cardiovascular applications. These applications were facilitated by innovations in MRI instrumentation that improved acquisition speed and in optimization of cardiovascular imaging protocols. Contrast-enhanced magnetic resonance angiography (CE MRA) has become the preferred method for fast and accurate assessment of common arterial structures such as the thoracic aorta, abdominal aorta, carotid arteries, renal arteries, and peripheral arteries. Myocardial perfusion and myocardial delayed enhancement MR are important contrast-enhanced techniques for the clinical evaluation for myocardial disease. Intravenous contrast agents have become integral to the clinical practice of cardiovascular magnetic resonance (MR) imaging.
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