Elliot K. Fishman, MD is Professor of Radiology and Oncology, and Director of Diagnostic Radiology and Body CT at Johns Hopkins Medical Institutions in Baltimore, MD

In March 2004, I served as the moderator for a second focus group discussion on The Use of Contrast in CT Angiography Applications. This distinguished panel of radiologists addressed many issues regarding the use of contrast in clinical CTA applications, including technical issues, as well as contrast and imaging features that affect the selection of contrast media for CTA applications. These presentations and panel discussions are published in this special online supplement to Applied Radiology to share these important insights with the radiology community.

The discussion was designed to provide some clarification on several issues, including:

• Which applications are best suited to the use of CTA?
• How can CTA be optimized?
• What is the role of contrast in CTA?
• Which contrast and acquisition protocols provide high-quality diagnostic images?
• Which factors influence the decision of which type, volume, and concentration of contrast to use?

The presentations and discussions provide each of the clinicians' experience with current literature on the clinical applications of CTA. These articles provide a great deal of valuable information for radiologists planning to add CTA to their practice, or those just beginning to perform these studies. More information on CTA, including additional protocols, is available at www.ctisus.com.

I would like to thank GE Healthcare for sponsoring the focus group and these proceedings, as well as Anderson Publishing for the arrangements and the publication. We would also like to thank all the panelists for their time and effort discussing CTA applications in great detail.