Garrett William Astary1, Svetlana Kantorovich2, Paul Richard Carney1,3, Malisa Sarntinoranont4, Thomas Harold Mareci5
1Biomedical Engineering, University of Florida, Gainesville, FL, United States; 2Neuroscience, University of Florida; 3Division of Pediatric Neurology, University of Florida; 4Mechanical & Aerospace Engineering, University of Florida; 5Biochemistry & Molecular Biology, University of Florida
A priori knowledge of contrast agent (CA) relaxivity (R1 and R2), which parameterizes how a CA alters neighboring water proton relaxation times (T1 and T2), can be used to determine the CA concentration in tissue, using pre- and post-contrast T1-weighted scans and knowledge of inherent tissue T1 values. The relaxivity of the CA gadolinium-labeled albumin (Gd-albumin) was measured in rat thalamus in vivo at 11.1 T and compared to the relaxivity of this CA measured in solution. R1 and R2 values in tissue were found to be reduced by 78% and 32%, respectively relative to solution values.