Rapid Dynamic PRF/δT1/T2* Monitoring for the Characterization of Heat-Induced USPIO Release from Thermosensitive Liposomes

Cyril Lorenzato¹, Alexandru Cernicanu², Baudouin Denis de Senneville¹, Pierre Smirnov¹, Marie-Edith Meyre³, Matthieu Germain³, Mario Ries¹, Chrit Moonen¹

Thermosensitive magnetoliposomes (TSM) can be prepared to contain drugs as well as super paramagnetic contrast agent. This would allow heat induced drug release, while detecting the release by simultaneously imaging relaxivity changes. Here, we propose a fast dynamic MRI method to simultaneously monitor temperature, T2*, and T1-changes in a gel doped with USPIO-charged TSM during heating. From a sigmoidal fit to the ∆T1 evolution the half-time of release at each voxel is obtained as well as estimate of the temperature of release, effectively characterizing the heat-induced release of USPIO from the TSM.