Contrast agents angiography

The pharmacokinetics of X-ray contrast agents used in angiography and urography are practically identical. These are characterized by extracellular distribution followed by renal excretion by glomerular filtration. The terminal half-life is approx. 1.5 h. An overview of the existing data on pharmacokinetics of X-ray contrast media in humans has been given by Bourin et al. [5]. 

The viscosity of contrast agent solutions determines the maximal rate of injection. Since in some techniques, e.g. angiography or CT, extremely high injection rates are mandatory (up to 20 mb s ), the viscosity of the preparation might be a limiting factor. Side-effects related to high viscosity, on the other hand, have not been determined unequivocally. 

Recent efforts to synthesize triiodinated benzene derivatives that are taken up by the liver have been published by Ranganathan [76]. This group synthesized lipophilic and/or amphiphilic derivatives of the angiography contrast agent, diatrizoate (Fig. 10). 

Acute sialadenitis ( iodide mumps ) has been described in a 70-year-old man who underwent femoral artery angiography with an iodine-containing contrast agent he gave a history of a similar episode 24 hours after a previous angiogram (56). 

Koronarangiographie—eine prospektive Untersuchung euthyreoten Patienten. [Thyroid function after iodine-containing contrast agent administration in coronary angiography a prospective study of euthyroid patients.] Z Kardiol 2001 90(10) 751-9. 

Both chelates have been launched as extracellular contrast agents using doses up to 3 mmol/kg body weight. Both can be formulated as 1.0 molar aqueous solutions with acceptable viscosity (Table 2). These highly concentrated agents are useful in fast dynamic studies such as brain perfusion and fast magnetic resonance angiography (MRA). 

Rosen BR, Belliveau JW, Vevea JM et al (1990) Perfusion imaging with NMR contrast agents. Magn Reson Med 14 249-265 Rother J, Wentz KU, Rautenberg W et al (1993) Magnetic resonance angiography in vertebrobasilar ischemia. Stroke 24 1310-1315... 

Visual hallucinations are very rare adverse effects of contrast media, with isolated reports after vertebral angiography or myelography. The mechanism of this adverse reaction could be similar to that reported in transient cortical blindness after infusion of contrast agents. However, other possibilities include a toxic effect of contrast media on the optic nerve, transient impairment of cerebral blood flow, which could be mediated through the release of the potent vasoconstrictor endothelin, or the formation of microclots. Two cases of visual hallucinations after coronary angiography have been reported (416). 

Tyekl, Z., Dunham, S.U., Midelfort, K., etal. (2007) Structural, kinetic, and thermodynamic characterization of the interconverting isomers of MS-325, a gadohnium(III)-based magnetic resonance angiography contrast agent. Inorganic Chemistry, 46, 6621-6631. 

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