Guanshu Liu1,2, Matthew M. Moake3, Assaf A. Gilad2,4, Muksit Jamil2, Yah-el Har-el2, Chris Long3, Piotr Walczak2,4, Jiangyang Zhang2, Amanda Cardona2, Marco A. DeLiso2, George Sgouros2, Jeff W.M. Bulte2,4, Peter C.M. van Zijl1,2, Michael T. McMahon1,2
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; 2Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
We developed a new MR-visible liposome system based on labeling with three distinct diamagnetic Chemical Exchange Saturation Transfer (DIACEST) agents, L-arginine, poly-L-lysine and glycogen. Using saturation frequency swept MRI with B0-correction, the accumulation of all three types of DIACEST liposomes in mouse popliteal lymph nodes could be visualized. As a proof of concept, we demonstrate the first in-vivo multi-contrast (multi-color) MRI using two DIACEST agents, L-arginine liposomes and poly-L-lysine liposomes, that were simultaneously injected to two footpads of the same mouse. This new system allows direct monitoring of liposomal uptake in lymph nodes without any paramagnetic or super-paramagnetic contrast material.