Mohammed Salman Shazeeb1, Christopher Sotak2
1Radiology, University of Massachusetts Medical School, Worcester, MA, United States; 2Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States
Manganese (Mn2+) is a T1 contrast agent used in MEMRI studies to visualize functional neural tracts and anatomy in the brain. In animal studies, high doses of Mn2+ are desired to maximize contrast. Unlike the intravenous Mn2+ injection, which results in fast initial bioelimination of Mn2+ from plasma, the subcutaneous (SC) injection can deliver a much higher dose of Mn2+ since it releases the Mn2+ slowly into the bloodstream while avoiding immediate hepatic elimination and minimizing toxic effects. SC Mn2+ injection led to a dose-dependent response of T1 relaxation times and a prolonged accumulation of Mn2+ in the rat brain.