Welcome the Chemistry of Contrast Media Group
Mark Woods holds academic appointments at both the Department of Chemistry at Portland State University and the Advanced Imaging Research Center at the nearby Oregon Health and Science University. His research bridges these two departments. Mark's focus is both fundamental and practical aspects of MRI contrast agent design and use, and cross-campus curriculum and graduate education.
We focus on two approaches to improving diagnosis by MRI: changing the way in which the contrast agent functions; or changing the way in which the contrast agent is used, or both.
The underlying mechanism by which all lanthanide-based contrast agents operate is by the exchange of solvent water molecule on and off the paramagnetic metal center. By understanding and controlling this water exchange process we can improve the function of MRI contrast agents. In addition we can also endow agent with properties that are useful for imaging specific diseases and biological functions. But, the exchange of water on and off the agent is not the only relevant water exchange process; in vivo water is compartmentalized and the contrast agent does not access all compartments. Contrast agents are exclusively extra-cellular. As a result the water within each compartment has a different exposure to the contrast agent. Water exchanges across the lipid membranes separating these compartments, and this exchange modulates how the contrast agent affects the MR image. Understanding this water exchange process is critical to determining how contrast agent affects the MR image.
Although we are fascinated by the understanding and controlling the coordination chemistry of lanthanide chelates with respect to MRI contrast agent design it is really the processes of water exchange that drive our research interests.
Our research breaks down into two distinct areas: