Abstract #1302

Miller G, Mugler III J, Cai J, Mata J, Cates G, de Lange E, Tobias W, Brookeman J

A feedback algorithm was incorporated as part of a 3D fast-gradient-echo sequence for hyperpolarized 3He lung imaging using variable flip angles. Signal measurements are acquired periodically during sequence execution, and the observed signal evolution is analyzed to calibrate the transmitter voltage and T1. Based on these measurements, the variable flip angle sequence is adjusted to ensure optimum usage of the available hyperpolarized magnetization.