Peter Caravan, PhD: The Future of MR Contrast Agents: Molecular MR and Gadolinium-free Contrast

Peter Caravan, PhD

Co-Director, Institute for Innovation in Imaging (i3)
Department of Radiology
Massachusetts General Hospital
Professor of Radiology
Harvard Medical School

Abstract

Contrast enhanced MR utilizes small, hydrophilic gadolinium chelates that freely distribute in the blood vessels and extravascular, extracellular space shortening the T1 relaxation time and generating positive contrast. Contrast enhanced MR identifies abnormal vasculature, e.g., stenoses, or abnormal distribution of the contrast agent, e.g. across disrupted blood brain barrier. Over the last 15 years, the safety of gadolinium-based contrast agents (GBCAs) has been questioned, especially in patients with severely impaired renal function and in those who require repeat scans. Our lab has developed a gadolinium-free contrast agent that is functionally equivalent to general purpose and liver specific GBCAs but does not contain gadolinium. We have also been developing contrast agents that expand the diagnostic armamentarium to provide specific molecular readouts. In particular, we have designed molecular MR probes that can detect and stage organ fibrosis, probes that can report on fibrotic disease activity (fibrogenesis) and be used to monitor treatment response, as well as probes whose MR signal is “turned-on” in the presence of reactive oxygen species. Here we will describe these innovations and potential applications in different disease models.

Short Bio

Peter Caravan leads a multidisciplinary and translational molecular imaging lab focused on the invention of novel molecular probes and their broad applications in cardiovascular, pulmonary, renal, and hepatic diseases as well as in cancers. His research spans novel chemistry technologies to advanced MRI and PET imaging in animal models through to applications in patient populations. Dr Caravan received his BSc (Hons) from Acadia University followed by a PhD in Inorganic Chemistry from the University of British Columbia under the mentorship of Prof. Chris Orwig. Following a NSERC post-doctoral fellowship with Prof. André Merbach at the Université de Lausanne, he worked in industry developing targeted MR probes including the blood pool agent gadofosveset (Ablavar). He joined the faculty of Harvard Medical School in 2007 and has been a continuously funded NIH researcher ever since. Dr. Caravan has published over 200 peer-reviewed articles, is a named inventor on over 25 issued patents, has brought multiple PET and MRI probes to first-in-human studies, and has co-founded two companies.