H217O as a ""smart"" T2 contrast agent with relaxivity sensitive to tissue metabolic status
Thelwall P, Silver X, Blackband S
University of Florida
H217O acts as a water proton T2 relaxation agent due to scalar coupling interactions between 1H and 17O. This T2 relaxivity effect is transmitted to bulk water by proton exchange, and thus T2 relaxivity is proportional to exchange rate. As this rate is modulated by sample pH and phosphate content, H217O acts as a T2 contrast agent sensitive to tissue metabolic status. We employed H217O to distinguish between normal and ischemic in vivo mouse brain in mice enriched with ~1.5% H217O. Thus H217O acts as a minimally invasive smart contrast agent with relaxivity sensitive to tissue metabolic status.