While the advances in cross-sectional imaging (ultrasound, computed tomography, and magnetic resonance) have decreased the use of radiographic contrast media, intravascular contrast agents are still essential for accurate detection and characterization of many anatomic abnormalities and diseases. There are unanswered questions concerning the toxicity of contrast media; however, it has been well established that approximately 5% of patients will have a reaction following intravascular injection of ionic agents.1 This is not an acceptable figure but it has stimulated the development of new agents. The new low osmolality contrast agents, particularly the nonionic media, have been shown to be safer than the currently used ionic agents; unfortunately, they are considerably more expensive. Fischer and coworkers' timely and important article addresses the difficult decisions and problems of using more costly, but apparently safer, contrast media.2
As expected, these new nonionic agents should be as efficacious as the standard ionic agents.